In this study, the physicochemical properties, in vitro fermentation, and interaction with Bacteroides ovatus of a purified fraction of polysaccharides from the root of Brassica rapa (BRP2-2) were investigated. It was demonstrated with an in vitro anaerobic fermentation model that BRP2-2 significantly increased (p < 0.05) the relative abundance of Bacteroides spp. After 24 h incubation of BRP2-2 with Bacteroides ovatus alone, 10.24 ± 0.69, 8.76 ± 0.48 and 3.37 ± 0.26 mM of acetate, propionate and isovalerate were produced, respectively. Moreover, transcriptome analysis of B. ovatus showed that 143 genes were up-regulated by BRP2-2, including five discrete polysaccharide utilization loci and two carbohydrate-active enzyme clusters. Based on the annotation of carbohydrate enzyme function, we speculate that BRP2-2 is a pectic polysaccharide containing homogalacturonan, rhamnogalacturonan I and rhamnogalacturonan II domains. These results suggested that BRP2-2 was degraded by B. ovatus, which produced metabolites with beneficial effects on host health.

Obesity and metabolic disorders are rising global health concerns, emphasizing the need for effective dietary interventions. High-viscosity dietary fibers such as bacterial cellulose (BC) and guar gum (GG) have unique properties that may complement each other in modulating gut microbiota and metabolic health. This study investigates their effects in high-fat diet-fed mice. BC and GG increase Bacteroides, which degrade polysaccharides and produce short-chain fatty acids (SCFAs), supporting metabolic health. BC enhances bile acid excretion and enriches Faecalibaculum, Duncaniella, and Paramuribaculum, promoting gut barrier integrity and reducing inflammation, potentially improving bile acid turnover and lipid metabolism. GG more effectively increases butyrate production by enhancing butyrate-producing bacteria, such as Clostridium XIVa and Kineothrix, and promotes Bifidobacterium, strengthening anti-inflammatory effects and gut barrier function. Both fibers upregulate bile acid biosynthesis, but BC's non-fermentable nature leads to higher bile acid excretion, while GG's fermentation causes lower excretion and broader liver metabolic changes. Both fibers reduce body weight, fat accumulation, and cholesterol levels, highlighting their potential in managing obesity and metabolic disorders. The complementary effects of BC and GG underscore the importance of fiber diversity for targeted dietary strategies to improve metabolic health.

Akkermansia muciniphila, a microorganism ubiquitously colonizing the mucosal layer of the human gut, has garnered significant scientific interest as a promising candidate for probiotic therapeutics. Its persistent identification in both laboratory and living organism studies underscores its potential physiological benefits, positioning it as a bacterium of paramount importance in promoting host health. This review examines the diversity and abundance of gut microbiota members, emphasizing the identification of microbial species engaged in cross-feeding networks with A. muciniphila. Insightful exploration into the mechanisms of cross-feeding, including mucin-derived nutrient exchange and metabolite production, unveils the intricate dynamics shaping microbial community stability. Such interactions contribute not only to the availability of essential nutrients within the gut environment but also to the production of metabolites influencing microbial community dynamics and host health. In conclusion, the cumulative evidence from in vitro and in vivo perspectives substantiates the notion that A. muciniphila holds tremendous promise as a next-generation probiotic. By leveraging its unique physiological benefits, particularly in mucosal health and metabolic regulation, A. muciniphila stands poised to revolutionize the landscape of probiotic interventions for enhanced host well-being.

In 2023, the World Obesity Atlas Federation concluded that more than 50% of the world's population would be overweight or obese within the next 12 years. At the heart of this epidemic lies the gut microbiota, a complex ecosystem that profoundly influences obesity-related metabolic health. Its multifaced role encompasses energy harvesting, inflammation, satiety signaling, gut barrier function, gut-brain communication, and adipose tissue homeostasis. Recognizing the complexities of the cross-talk between host physiology and gut microbiota is crucial for developing cutting-edge, microbiome-targeted therapies to address the global obesity crisis and its alarming health and economic repercussions. This narrative review analyzed the current state of knowledge, illuminating emerging research areas and their implications for leveraging gut microbial manipulations as therapeutic strategies to prevent and treat obesity and related disorders in humans. By elucidating the complex relationship between gut microflora and obesity, we aim to contribute to the growing body of knowledge underpinning this critical field, potentially paving the way for novel interventions to combat the worldwide obesity epidemic.

Obesity is a major global public health challenge, affecting billions and serving as a primary risk factor for many chronic diseases. Certain probiotics have shown promise in regulating energy balance and enhancing fat metabolism, offering potential strategies for managing obesity. In this study, we evaluated three strains of Bifidobacterium adolescentis and identified B. adolescentis FJSSZ23M10 as the most effective in alleviating high-fat diet (HFD)-induced obesity. This strain significantly reduced weight gain, improved abnormal serum biochemical indicators, decreased lipid accumulation in adipocytes, and enhanced energy expenditure. Furthermore, B. adolescentis FJSSZ23M10 treatment modulated the gut microbiota, notably increasing the abundance of Bifidobacterium and Faecalibaculum. Untargeted metabolomic analysis revealed that B. adolescentis FJSSZ23M10 uniquely upregulated beneficial metabolites, such as butyrate and pyruvic acid, suggesting its superior metabolic impact. Genomic analysis indicated that B. adolescentis FJSSZ23M10 harbored the highest abundance of unassigned genes and carbohydrate-active enzymes (CAZymes) compared to the other strains, highlighting its superior functional potential. Combining the shared and unique modifications in gut microbiota, metabolites, and genomic annotations, the study highlights that genomic differences among probiotics could shape their effects on gut microbiota and metabolites. Conclusively, the study underscores the critical role of probiotic genomic characteristics in determining their functional efficacy and suggests that the intake of the B. adolescentis FJSSZ23M10 strain with enriched genomic features, such as CAZymes, could represent a novel genomic-based strategy for alleviating obesity through gut microbiota modulation and metabolic regulation.

Studies have indicated a potential relationship between gut microbiota and renal cell carcinoma. However, the causal relationship between various types of gut microbiota and renal cell carcinoma, as well as the role of inflammatory protein as mediators, remains unclear.

This study aimed to identify the relationship between gut microbiota, inflammatory protein, and renal cell cancer through a large-scale genome-wide association study (GWAS) utilizing pooled data. We employed Mendelian randomization (MR) to investigate the causal relationship among these variables. Inverse variance weighting (IVW) was utilized as the primary statistical method. Furthermore, we examined the mediating role of inflammatory protein in the pathway through which gut microbiota influences the development of renal cell cancer.

The analysis revealed 12 positive causal relationships and 15 negative causal relationships between the genetic liability of gut microbiota and renal cell cancer. Furthermore, there were three positive causal relationships and one negative causal relationship between inflammatory proteins and renal cell cancer. There were two axes of relationships in which gut microbiota promote the development of renal cell cancer. through inflammatory proteins acting as mediators.

Gut microbiota and inflammatory protein were causally related to renal cell cancer, and inflammatory protein were intermediary factors in the pathway between gut microbiota and renal cell cancer.

The importance of the intestinal microbita in a multitude of physiological processes is well-evidenced. These include metabolism of nutrients and xenobiotics, biosynthesis of vitamin K and vitamin B12, immunomodulation, maintenance of the gut mucosal barrier integrity and protection against some pathogens. Interindividual differences in the intestinal microbiota composition have impacts on health. The bioavailability and activity of some pharmaceuticals are heavily influenced by interindividual variability in metabolism, which has a genetic basis. This variability, primarily occurring in the liver but also in the intestine, has been studied extensively. Despite the advancement of this field - pharmacogenetics - its integration into clinical practice remains limited for reasons discussed herein. This highlights the even greater challenge of applying emerging knowledge on variability in the gut microbiota to drug therapy. However, ignoring these opportunities would be a mistake. While clinical applications of microbiota-guided drug therapy are currently absent and the ideas in this article are largely theoretical, research is uncovering that in cases where a substantial portion of a drug or its metabolites reaches the colon, or where drugs are formulated for colonic delivery, the gut microbiota can significantly affect drug metabolism and activity. Greater focus should be placed on research into how interindividual variability in the intestinal microbiome can modify pharmaceutical bioavailability and activity. This article is deliberately speculative and exploratory but proposes that, though there are still no clinical examples of microbiome-guided drug therapy, these interactions could afford opportunities for improvements in personalised medicine and also for drug design.

Atrial cardiomyopathy is a multifaceted heart disease characterized by structural and functional abnormalities of the atria and is closely associated with atrial fibrillation and its complications. Its etiology involves a number of factors, including genetic, infectious, immunologic, and metabolic factors. Recent research has highlighted the critical role of the gut microbiota in the pathogenesis of atrial cardiomyopathy, and this is consistent with the gut-heart axis having major implications for cardiac health. The aim of this work is to bridge the knowledge gap regarding the interactions between the gut microbiota and atrial cardiomyopathy, with a particular focus on elucidating the mechanisms by which gut dysbiosis may induce atrial remodeling and dysfunction. This article provides an overview of the role of the gut microbiota in the pathogenesis of atrial cardiomyopathy, including changes in the composition of the gut microbiota and the effects of its metabolites. We also discuss how diet and exercise affect atrial cardiomyopathy by influencing the gut microbiota, as well as possible future therapeutic approaches targeting the gut-heart axis. A healthy gut microbiota can prevent disease, but ecological dysbiosis can lead to a variety of symptoms, including the induction of heart disease. We focus on the pathophysiological aspects of atrial cardiomyopathy, the impact of gut microbiota dysbiosis on atrial structure and function, and therapeutic strategies exploring modulation of the microbiota for the treatment of atrial cardiomyopathy. Finally, we discuss the role of gut microbiota in the treatment of atrial cardiomyopathy, including fecal microbiota transplantation and oral probiotics or prebiotics. Our study highlights the importance of gut microbiota homeostasis for cardiovascular health and suggests that targeted interventions on the gut microbiota may pave the way for innovative preventive and therapeutic strategies targeting atrial cardiomyopathy.

Dietary fibers influence the composition of the human gut microbiota and directly contribute to its downstream effects on host health. As more research supports the use of glycans as prebiotics for therapeutic applications, the need to identify the gut bacteria that metabolize glycans of interest increases. Fructo-oligosaccharide (FOS) is a common diet-derived glycan that is fermented by the gut microbiota and has been used as a prebiotic. Despite being well studied, we do not yet have a complete picture of all FOS-consuming gut bacterial taxa. To identify new bacterial consumers, we used a short exposure of microbial communities in a stool sample to FOS or galactomannan as the sole carbon source to induce glycan metabolism genes. We then performed metatranscriptomics, paired with whole metagenomic sequencing, and 16S amplicon sequencing. The short incubation was sufficient to cause induction of genes involved in carbohydrate metabolism, like carbohydrate-active enzymes (CAZymes), including glycoside hydrolase family 32 genes, which hydrolyze fructan polysaccharides like FOS and inulin. Interestingly, FOS metabolism transcripts were notably overexpressed in Blautia species not previously reported to be fructan consumers. We therefore validated the ability of different Blautia species to ferment fructans by monitoring their growth and fermentation in defined media. This pulse metatranscriptomics approach is a useful method to find novel consumers of prebiotics and increase our understanding of prebiotic metabolism by CAZymes in the gut microbiota.

Complex carbohydrates are key contributors to the composition of the human gut microbiota and play an essential role in the microbiota's effects on host health. Understanding which bacteria consume complex carbohydrates, or glycans, provides a mechanistic link between dietary prebiotics and their beneficial health effects, an essential step for their therapeutic application. Here, we used a pulse metatranscriptomics pipeline to identify bacterial consumers based on glycan metabolism induction in a human stool sample. We identified novel consumers of fructo-oligosaccharide among Blautia species, expanding our understanding of this well-known glycan. Our approach can be applied to identify consumers of understudied glycans and expand our prebiotic repertoire. It can also be used to study prebiotic glycans directly in stool samples in distinct patient populations to help delineate the prebiotic mechanism.

Intestinal dysbiosis was considered a pivotal pathological mechanism underlying sarcopenia. Despite the fervor surrounding research in this domain, substantial controversy persists regarding the obtained outcomes.

To systematically summarized the disparities in gut microbiota composition between the group afflicted by sarcopenia and non-sarcopenia controls.

PubMed, Medline, CINAHL, EMBASE, Scopus, Web of Science and Google Scholer, Cochrane Library and gray literature sources were systematically searched for in randomized controlled trials. Meta-analysis and random-effects meta-regression were conducted using Rev. Man 5.3. Overall effect was measured using Hedges's g and determined using Z-statistics. Cochran's Q test and I 2 were used to investigate heterogeneity. The Newcastle-Ottawa Scale was used to assess overall quality of evidence.

Ten studies, including 421 cases of sarcopenia and 1,642 cases of controls, were included in the meta-analysis. Patients with sarcopenia showed significantly reduced gut microbiota in α diversity, and β diversity was significantly different in 8/9 of included studies. We also found more abundance of phylum Proteobacteria and genus Escherichia-Shigella, and less abundance of phylum Firmicutes and genus Faecalibacterium, Prevotella 9, Blautia in the sarcopenia group.

The gut microbiota composition in patients with sarcopenia has undergone alterations, serving as a fundamental reference for further investigation into the potential pathogenic mechanisms and treatment strategies for sarcopenia.

The residual black wolfberry fruit (RBWF) is rich in nutrients and contains a diverse range of active substances, which may offer a viable alternative to antibiotics. This experiment was conducted to investigate the impact of varying levels of RBWF on the growth performance and rumen microorganisms of fattening sheep, and to quantify its economic benefits.

In this experiment, 40 three-month-old and male Duolang sheep with an average weight of 29.85 kg, selected for their propensity to gain weight, were randomly assigned to one of four groups, with ten sheep in each group. To this end, each group was fed with a different proportion of RBWF (0%, 2%, 5%, 8%), and rumen fluid samples were collected to detect differences in fermentation parameters and microbial structure.

The findings indicate that the dry matter intake, OM and NDF apparent digestibility of Duolang sheep in the H2 group were found to be significantly higher than those observed in the other groups (P < 0.05). The concentration of volatile fatty acids (VFAs), including acetate, propionate, iso-butyrate, butyrate and iso-valerate, in rumen fluid demonstrated a linear increase with the supplementation of RBWF in the diet (P < 0.05). The dominant bacteria in the rumen of Duolang sheep were identified as Prevotella, Christensenellaceae R7 group, NK4A214 group, Ruminococcus, and Rikenellaceae RC9 gut group. Compared with the CK group, the relative abundance of Prevotella, NK4A214 group, unclassified Prevotellaceae and Lachnospiraceae NK3A20 group in the rumen of sheep in each experimental group increased to varying degrees. The gross profit of the H2 group was significantly higher than that of the other groups.

In conclusion, the supplementation of RBWF has been demonstrated to enhance the growth performance of Duolang sheep, optimise rumen fermentation parameters, and ultimately increase gross profit, of which 5 % is the best.

Metabolic disease is a multifaceted condition characterized by the disruption of numerous metabolic parameters within the host. Its prevalence has surged significantly in recent years and it has become a prominent non-communicable disease worldwide. The effect of gut microbiota on various beige fat induction is well studied, while the mechanisms behind the link remain unclear. Given that gut microbiota-derived metabolites (meta-metabolites) secreted in the gut serve as a key mode of communication with their host through direct circulation or indirect host physiology modification, understanding the effect of meta-metabolites on adipose tissue is essential.

In our previous in-vivo studies, we observed a correlation between gut microbiota and the formation of beige fat. In this study, we further aimed to validate this correlation by treating the adipocyte cell line (3T3-L1) with meta-metabolites collected from the cecum of mice exhibiting beige adipose tissue formation. Additionally, we treated the adipocyte cell line with known beige fat inducers (L-Rhamnose and Ginsenoside) to assess meta-metabolites' efficacy on beige fat formation.

Upon treatment with the meta-metabolites from the antibiotic-treated mice, we observed a significant increase in lipid metabolism and beige-specific gene expression. Analyzing the metabolites in these cells revealed that a set of metabolites potentially govern adipocytes, contributing to a metabolically active state. These effects were at par or even better than those of cells treated with L-Rhamnose or Ginsenoside.

This research sheds light on the intricate interplay between microbial metabolites and adipose tissue, offering valuable clues for understanding and potentially manipulating these processes for therapeutic purposes.

To evaluate the effect of Weichang'an pill (, WCAP) on functional dyspepsia (FD) and explore its regulation of brain-gut peptides (BGPs) and gut microbiota balance as a potential treatment mechanism.

The "0 ℃ saline gavage + irregular feeding and tail clamp" method was used to establish the FD rat model, excluding the normal group. The successfully established FD rat models were randomly divided into the model group and the WCAP1 (WC1), WCAP2 (WC2), WCAP3 (WC3), WCAP4 (WC4), WCAP5 (WC5), and Domperidone (Dom) groups (n = 10 per group). The unhandled rats were designated as the control group. The gastrointestinal motility of the rats was evaluated using the charcoal propulsion test. Histopathology was assessed by hematoxylin and eosin (HE) staining. The enzyme-linked immunosorbnent assay method was used to detect the levels of motilin (MTL), gastrin (GAS), vasoactive intestinal peptide (VIP), and somatostatin (SS) in the serum from each group. In addition, the gut microbiota composition of fecal samples was analyzed using 16S rRNA sequencing.

Rat models were successfully established according to data from rat state, gastrointestinal motility assessments, and HE staining. WCAP improved FD symptoms by accelerating the gastric emptying and small intestinal transit of FD rats. Mechanistically, WCAP increased the levels of GAS and MTL and reduced the levels of VIP and SS. Moreover, WCAP treatment restored the total relative abundance of Firmicutes and Bacteroidetes, increased the species richness of the gut flora, and modulated the changes in the composition and function of the gut microbiota.

WCAP can effectively promote the recovery of gastrointestinal motility disorders in FD rats. The mechanism may be related to regulating the secretion of BGPs and the composition of the gut microbiota.

Microplastics (MPs), defined as plastic particles smaller than 5 mm, are increasingly recognized as environmental contaminants with potential health risks. These emerge as breakdown products of larger plastics and are omnipresent in marine, freshwater, and terrestrial ecosystems. They are primarily composed of polymers such as polyethylene, polypropylene, polystyrene, and additives that enhance their performance. MPs also adsorb harmful environmental chemicals like persistent organic pollutants and heavy metals, posing risks to human and environmental health. Human exposure to MPs occurs mainly through ingestion and inhalation, with MPs detected in food products, water, and even the air. MPs have been shown to accumulate in the gastrointestinal tract, disrupting the gut microbiome, and causing dysbiosis-a harmful imbalance between beneficial and harmful bacteria. This disruption has been linked to various health issues, including gastrointestinal disorders, systemic inflammation, and chronic diseases. Furthermore, the gut-brain axis may be affected, with potential neuroinflammatory consequences. As research continues to unravel the health impacts of MP exposure, understanding the mechanisms of accumulation and the broader implications on human health is crucial. This review highlights the effects of MPs on human health, emphasizing their impact on the gut microbiome. We discuss the potential connections between MP exposure and cardiometabolic and inflammatory diseases, and disorders related to the Gut-Brain Axis. By synthesizing the latest research, this work sheds light on the silent yet pervasive threat posed by MPs and underscores the importance of further studies to understand their health impacts fully.

Roux-en-Y (RYGB) and one anastomosis gastric bypass (OAGB) represent two of the most used bariatric/metabolic surgery (BMS) procedures. Gut microbiota (GM) shift after bypass surgeries, currently understated, may be a possible key driver for the short- and long-term outcomes.

Prospective, multicenter study enrolling patients with severe obesity, randomized between OAGB or RYGB. Fecal and blood samples were collected, pre- (T0) and 24 months postoperatively (T1). GM was determined by V3-V4 16S rRNA regions sequencing and home-made bioinformatic pipeline based on Qiime2 plugin and R packages.

To compare OAGB vs RYGB microbiota profile at T1 and its impact on metabolic and nutritional status.

54 patients completed the study, 27 for each procedure. An overall significant variation was detected in anthropometric and serum nutritional parameters at T1, with a significant, similar decrease in overall microbial alpha and beta diversity observed in both groups. An increase in relative abundances of Actinobacteria and Proteobacteria and a reduction of Bacteroidetes, no significant changes in Firmicutes and Verrucomicrobia, with an increase of the Firmicutes/Bacteroidetes ratio were observed.

BMS promotes a dramatic change in GM composition. This is the first multicenter, RCT evaluating the impact of OAGB vs Roux-en-Y bypass on GM profile. The bypass technique per se did not impact differently on GM or other examined metabolic parameters. The emergence of slightly different GM profile postoperatively may be related to clinical conditions or may influence medium or long-term outcomes and as such GM profile may represent a biomarker for bariatric surgery's outcomes.

Microorganisms are vital for the health of marine invertebrates, and their assembly is driven by both deterministic and stochastic factors that regulate residents (innate to the host) and transients (from ambient water). However, the role of water microbiota and the significance of deterministic and stochastic processes in aquatic hosts facing mortality threats are largely unknown. This study examines the shifts in water microbiota during an oyster mortality event using amplicon sequencing and compared with those of resident oysters to disentangle the balance of the deterministic and stochastic factors involved. Water temperature and dissolved oxygen significantly shape the microbial community with a distinct monthly pattern, and Cyanobacteria blooms might exacerbate oyster mortality. The comparative analysis of microbial communities in oysters and water revealed that ≤ 21% of the genera were shared between oysters and water, implying that water microbiota cannot easily transfer into oysters. Furthermore, these shared genera had different functions, with oysters more involved in promoting host digestion and nutrient acquisition and water bacteria enriched more in functions promoting their own growth and survival. These findings illustrate that oysters may possess specific selection or barrier mechanisms that permit a small percentage of transients, controlled by stochastic factors and having a minimal effect on oyster mortality, to enter, whereas the majority of oyster microbiota are residents governed by deterministic factors. Consequently, oysters exhibit some plasticity in their symbiotic microbiota, enabling them to maintain microbial homeostasis and adapt to complex microbial surroundings. This may be a shared mechanism among marine invertebrates for survival in complex marine environments.IMPORTANCEPacific oysters are widely cultured and play vital ecological roles. However, the summer mortality hinders sustainable oyster farming. Untangling causative mechanisms of oyster mortality is a complex task due to the intricate "interactome" involving environmental factors, hosts, and pathogens. Interactions between hosts and microorganisms offer an ideal avenue for investigating the truth. We systematically investigated the microbial community in water and resident oysters during a summer mortality event and proposed that the assembly of oyster microbiota is primarily governed by deterministic processes independent of mortality. Pathogens mainly originate from resident members of the oyster microbiota, with a limited influence from the microbial community in the water. Additionally, environmental degraders, such as Cyanobacteria blooms, cannot be overlooked as a contributing factor of oyster mortality. This study evaluated the weight of deterministic and stochastic factors in microbial assembly during an oyster mortality event and greatly broadened our understanding of the "interactome" through the interaction between oysters and water in microbiota.

Deranged gut microbiota can release increased levels of uremic toxins leading to exacerbated kidney injury. In diabetic kidney disease (DKD), phenyl sulfate (PS) derived from tyrosine catabolism by gut microbiota has been demonstrated to be both an early diagnostic marker and a therapeutic target. In this perspective article, we summarize PS generation pathways and recent findings on PS and kidney injury in DKD. Increasing evidence has shown that the underlying mechanisms of PS-induced kidney injury mainly involve oxidative stress, redox imbalance, and mitochondrial dysfunction, which all may be targeted to attenuate PS-induced kidney injury. For future research directions, we think that a deeper understanding of the pathogenic role of PS in kidney injury using a variety of diabetic animal models should be investigated. Moreover, we also suggest beneficial approaches that could be used to mitigate the deleterious effect of PS on the kidney. These approaches include caloric restriction, tyrosine restriction, and administration of ketogenic drugs, ketogenic diets or natural products; all of which should be conducted under obese and diabetic conditions.

Increasing awareness regarding health promotion and disease prevention has driven inclusion of fermented foods and beverages in the daily diet. These are the enormous sources of beneficial microbes, probiotics. This study aims to isolate yeast strains having probiotic potential and effectivity against colitis. Initially, ninety-two yeast strains were isolated from Haria, an ethnic fermented beverage of West Bengal, India. Primary screening was done by their acid (pH 4) and bile salt (0.3%) tolerance ability. Four potent isolates were selected and found effective against Entamoeba histolytica, as this human pathogen is responsible to cause colitis. They were identified as Saccharomyces cerevisiae. They showed luxurious growth even at 37 oC, tolerance up to 5% of NaCl, resistance to gastric juice and high bile salt (2.0%) and oro-gastrointestinal transit tolerance. They exhibited good auto-aggregation and co-aggregation ability and strong hydrophobicity. Finally, heat map and principal component analysis revealed that strain Y-89 was the best candidate. It was further characterised and found to have significant protective effects against DSS-induced colitis in experimental mice model. It includes improvement in colon length, body weight and organ indices; reduction in disease activity index; reduction in cholesterol, LDL, SGPT, SGOT, urea and creatinine levels; improvement in HDL, ALP, total protein and albumin levels; decrease in coliform count and restoration of tissue damage. This study demonstrates that the S. cerevisiae strain Y-89 possesses remarkable probiotic traits and can be used as a potential bio-therapeutic candidate for the prevention of colitis.

The causes of functional constipation (FC) in adults are unclear, but changes in the gut microbiome may play an important role. The present study aimed to assess the relationship between urinary metabolites of dopamine and serotonin and some dysbiosis indicators in patients with FC. The study included 40 healthy women and 40 women with FC aged 21-46 years.

Urinary levels of homovanillic acid (HVA), 5-hydoxyindoleacetic acid (5-HIAA), p-hydroxyphenylacetic acid (PhAc), and 3-indoxyl sulfate, as final metabolites of dopamine, serotonin, and indole pathway, respectively, were determined using the LC-Ms/Ms method. However, hydrogen-methane and ammonia breath tests were performed. The GA-map Dysbiosis Test was used to identify and characterize the dysbiosis index (DI).

In patients with FC, the DI was significantly higher than in the control group: 4.05 ± 0.53 vs. 1.52 ± 0.81 points (p < 0.001), but the number of many types of bacteria varied among individuals. The levels of HVA were higher, while 5-HIAA levels were lower in patients. Moreover, the HVA/5-HIAA ratio had a positive correlation with DI as well as with the severity of symptoms.

In patients with functional constipation, the balance in dopamine and serotonin secretion is disturbed, which is associated with changes in the gut microbiome.

Weaning is a critical stage in the swine production cycle, as young pigs need to adjust to sudden and dramatic changes in their diet and environment. Among the various organ systems affected, the gastrointestinal tract is one of the more severely impacted during this transition. Traditionally, challenges at weaning have been managed by prophylactic use of antibiotics, which not only provides protection against diarrhea and other gut dysfunction but also has growth-promoting effects. With banning or major restrictions on the use of antibiotics for this purpose, various alternative products have been developed as potential replacements, including direct-fed microbials (DFMs) such as probiotics and postbiotics. As their efficiency needs to be improved, a continued effort to gain a deeper understanding of their mechanism of action is necessary. In this context, this report presents a study on the impact of a Lactobacillus-based probiotic (LPr) and a Bifidobacterium-based postbiotic (BPo) when added to the diet during the nursery phase. For animal performance, an effect was observed in the early stages (Day 0 to Day 10), as pigs fed diets supplemented with either DFMs were found to have higher average daily feed intake (ADFI) compared to pigs fed the control diet (p < 0.05). Histological analysis of intestinal morphology on D10 revealed that the ileum of supplemented pigs had a higher villus height/crypt depth ratio (p < 0.05) compared to controls, indicating a benefit of the DFMs for gut health. In an effort to further explore potential mechanisms of action, the effects of the DFMs on gut microbial composition were investigated using fecal microbial communities as a non-invasive representative approach. At the bacterial family level, Lactobacillaceae were found in higher abundance in pigs fed either LPr (D10; p < 0.05) or BPo (D47; p < 0.05). At the Operational Taxonomic Unit (OTU) level, which can be used as a proxy to assess species composition, Ssd-00950 and Ssd-01187 were found in higher abundance in DFM-supplemented pigs on D47 (p < 0.05). Using nucleotide sequence identity, these OTUs were predicted to be putative strains of Congobacterium massiliense and Absicoccus porci, respectively. In contrast, OTU Ssd-00039, which was predicted to be a strain of Streptococcus alactolyticus, was in lower abundance in BPo-supplemented pigs on D47 (p < 0.05). Together, these results indicate that the DFMs tested in this study can impact various aspects of gut function.

Tea is a highly popular beverage, primarily due to its unique flavor and aroma as well as its perceived health benefits. The impact of tea on the gut microbiome could be an important means by which tea exerts its health benefits since the link between the gut microbiome and health is strong. This review provided a discussion of the bioactive compounds in tea and the human gut microbiome and how the gut microbiome interacts with tea polyphenols. Importantly, studies were compiled on the impact of differently processed tea, which contains different polyphenol profiles, on the gut microbiota from in vivo animal feeding trials, in vitro human fecal fermentation experiments, and in vivo human feeding trials from 2004-2024. The results were discussed in terms of different tea types and how their impacts are related to or different from each other in these three study groups.

Immunoglobulin A (IgA) is a major gut antibody that coats commensal gut bacteria and contributes to shaping a stable gut bacterial composition. Although previous studies have shown that cyclic oligosaccharides, including cyclic nigerosyl-1,6-nigerose (CNN) and cyclodextrins (CDs, including αCD, βCD, and γCD), alter the gut bacterial composition, it remains unclear whether cyclic oligosaccharides modify the IgA coating of gut bacteria, which relates to cyclic oligosaccharide-induced alteration of the gut bacterial composition. To address this issue, mice were maintained for 12 weeks on diets containing CNN, αCD, βCD, or γCD; the animals' feces were evaluated for their bacterial composition and the IgA coating index (ICI), a measure of the degree of IgA coating of bacteria. We observed that the intake of each cyclic oligosaccharide altered the gut bacterial composition, with changes in the ICI found at both the phylum and genus levels. The ICI for Bacillota, Lachnospiraceae NK4A136 group, UC Lachnospiraceae, and Tuzzerella were significantly and positively correlated with the relative abundance (RA) in total bacteria for these bacteria; in contrast, significant correlations were not seen for other phyla and genera. Our observations suggest that cyclic oligosaccharide-induced modulation of the IgA coating of gut bacteria may partly relate to changes in the community structure of the gut bacteria.

Being overweight and obesity are significant global public health challenges due to their association with adipose tissue dysfunction, pro-inflammatory marker production, and alterations in gut microbiota composition. To explore the relationship between gut microbiota, dietary factors, and inflammatory markers in overweight or obese women, we conducted a cross-sectional study involving a healthy group (n = 20) and an overweight or obese group (n = 75). We collected data, including clinical, anthropometric, and dietary assessments, and carried out a blood biochemical analysis, the measurement of inflammatory biomarkers (hs-CRP, IL-6, and TNF-α), and the 16S rRNA gene sequencing of fecal samples. The gut microbiota analysis revealed notable differences in alpha and beta diversity between the two groups. Moreover, the abundance of gut microbiota in the overweight or obese group correlated positively with adiposity markers, blood pressure, lipid profiles, and inflammatory markers. These findings highlight significant changes in gut microbiota associated with obesity, potentially implicating pathways such as lipopolysaccharide biosynthesis. Understanding the role of the gut microbiome in obesity could reveal specific avenues for intervention.

The gut microbiota is crucial in human health and diseases. Traditional Chinese Medicine Constitution (TCMC) divides people into those with a balanced constitution (Ping-he [PH]) and those with an unbalanced constitution. Dampness-heat constitution (Shi-re [SR]) is a common unbalanced constitution in the Chinese population and is susceptible to diseases. However, unbalanced constitutions can be regulated by Chinese medicine and lifestyle interventions in clinical practice. Ermiao Pill (EMP) is a Chinese medicine known for clearing heat and draining dampness and improving SR. However, the efficacy and mechanism of EMP are unclear.

To determine alterations in the gut microbiota and metabolome in SR and any changes after EMP treatment combined with lifestyle intervention.

Randomized clinical trial.

We enrolled 112 healthy SR individuals and evaluated the efficacy of EMP along with lifestyle interventions. We further assessed serum cytokine levels, serum and urinary metabolomes, and the gut microbiota by 16S rRNA gene sequencing analysis before and after the EMP and lifestyle interventions.

107 SR individuals (55 in the intervention group and 52 in the control group) completed the 1-month-intervention and 1-year-follow-up. The intervention group significantly improved their health status within 1 month, with a reduced SR symptom score, and the efficacy lasted to the 1-year follow-up. The control group needed a further 6 months to reduce the SR symptom score. The gut microbiota of PH individuals was more diverse and had significantly higher proportions of many bacterial species than the SR. Microbiota co-occurrence network analysis showed that SR enriches metabolites correlating with microbial community structure, consistent with traits of healthy SR-enriched microbiota.

EMP combined with lifestyle intervention produced health benefits in SR individuals. Our study indicates a pivotal role of gut microbiota and metabolome alterations in distinguishing between healthy SR and PH. Furthermore, the study reveals structural changes of gut microbiota and metabolites induced by EMP and lifestyle intervention. The treatment enriched the number of beneficial bacteria, such as Akkermansia muciniphila and Lactobacillus in the gut. Our findings provide a strong indication that several metabolite factors are associated with the gut microbiota. Moreover, the gut microbiome and metabolome might be powerful tools for TCMC diagnosis and personalized therapy.

Bats are the natural reservoir hosts for SARS-related coronavirus (SARSr-CoV) and other highly pathogenic microorganisms. Therefore, it is conceivable that an individual bat may harbor multiple microbes. However, there is limited knowledge on the overall co-circulation of microorganisms in bats. Here, we conducted a 16-year monitoring of bat viruses in south and central China and identified 238 SARSr-CoV positive samples across nine bat species from ten provinces or administrative districts. Among these, 76 individual samples were selected for further metagenomics analysis. We found a complex microenvironment characterized by the general co-circulation of microbes from two different sources: mammal-associated viruses or environment-associated microbes. The later includes commensal bacteria, enterobacteria-related phages, and insect or fungal viruses of food origin. Results showed that 25% (19/76) of the samples contained at least one another mammal-associated virus, notably alphacoronaviruses (13/76) such as AlphaCoV/YN2012, HKU2-related CoV and AlphaCoV/Rf-HuB2013, along with viruses from other families. Notably, we observed three viruses co-circulating within a single bat, comprising two coronavirus species and one picornavirus. Our analysis also revealed the potential presence of pathogenic bacteria or fungi in bats. Furthermore, we obtained 25 viral genomes from the 76 bat SARSr-CoV positive samples, some of which formed new evolutionary lineages. Collectively, our study reveals the complex microenvironment of bat microbiome, facilitating deeper investigations into their pathogenic potential and the likelihood of cross-species transmission.

Aberrant activation of the classic renin-angiotensin system (RAS) and intestinal micro dysbiosis adversely affect insulin resistance (IR), dyslipidemia, and other metabolic syndrome markers. However, the action of angiotensin-converting enzyme 2 (ACE2) and gut health in systemic homeostasis vary, and their interaction is not completely understood.

We adopted a combinatory approach of metabolomics and fecal 16S rRNA analysis to investigate gut microbiota and metabolite in two different mouse models, ACE2 knockout (ACE2 KO) mice and the ACE2-overexpressing obese mice.

16S rRNA gene sequencing revealed that ACE2 influences microbial community composition and function, and ACE2 KO mice had increased Deferribacteres, Alcaligenaceae, Parasutterella, Catenibacterium, and Anaerotruncus, with decreased short-chain fatty acid (SCFA)-producing bacteria (Marvinbryantia and Alistipes). In contrast, ACE2-overexpressed mice exhibited increased anti-inflammatory probiotic (Oscillospiraceae, Marinifilaceae, and Bifidobacteriaceae) and SCFA-producing microbes (Rikenellaceae, Muribaculaceae, Ruminococcaceae, Odoribacter, and Alistipes) and decreased Firmicutes/Bacteroidetes, Lactobacillaceae, Erysipelotrichaceae, and Lachnospiraceae. Metabolome analysis indicated differential metabolites in ACE2 KO and ACE2-overexpression mice, especially the glucolipid metabolism-related compounds. Furthermore, correlation analysis between gut microbiota and metabolites showed a dynamic mutual influence affecting host health.

Our study confirms for the first time a significant association between ACE2 status and gut microbiome and metabolome profiles, providing a novel mechanism for the positive effect of ACE2 on energy homeostasis.

Disruption of the gut microbiota causes metabolic dysfunction, and intervention in the gut microbiota has the potential to improve host glucose metabolism. Akkermanisa muciniphila is an intestinal bacterium involved in anti-obesity and insulin resistance. Developing interventions to increase A. muciniphla would be useful for new treatment strategies. In this study, we screened herbal drug extracts that promoted the growth of A. muciniphila. Among the 123 herbal drugs, five herbal drug extracts significantly increased A. muciniphila DNA levels compared with that in controls. In particular, Dioscoreae rhizoma extract increased the growth of A. muciniphila in the intestines of mice fed a high-fat diet and improved obesity. It significantly reduced body weight gain, improved glucose tolerance even when the administration was initiated after the induction of dietary obesity. These results suggest that herbal drug extracts, such as Dioscoreae rhizome, that increase A. muciniphila could be a new therapeutic strategy for metabolic syndrome.

The online version contains supplementary material available at 10.1007/s13340-024-00713-w.

The glucose-lowering drug metformin alters the composition of the gut microbiome in patients with type 2 diabetes mellitus (T2DM) and other diseases. Nevertheless, most studies on the effects of this drug have relied on fecal samples, which provide limited insights into its local effects on different regions of the gut. Using a high-fat diet (HFD)-induced mouse model of T2DM, we characterize the spatial variability of the gut microbiome and associated metabolome in response to metformin treatment. Four parts of the gut as well as the feces were analyzed using full-length sequencing of 16S rRNA genes and targeted metabolomic analyses, thus providing insights into the composition of the microbiome and associated metabolome. We found significant differences in the gut microbiome and metabolome in each gut region, with the most pronounced effects on the microbiomes of the cecum, colon, and feces, with a significant increase in a variety of species belonging to Akkermansiaceae, Lactobacillaceae, Tannerellaceae, and Erysipelotrichaceae. Metabolomics analysis showed that metformin had the most pronounced effect on microbiome-derived metabolites in the cecum and colon, with several metabolites, such as carbohydrates, fatty acids, and benzenoids, having elevated levels in the colon; however, most of the metabolites were reduced in the cecum. Thus, a wide range of beneficial metabolites derived from the microbiome after metformin treatment were produced mainly in the colon. Our study highlights the importance of considering gut regions when understanding the effects of metformin on the gut microbiome and metabolome.

Antipsychotics (APs) have been increasingly prescribed for psychiatric disorders from schizophrenia to disruptive behavioral conditions. These drugs have been associated with considerable side effects, such as weight gain, and increasing evidence has also indicated that its use impacts gut microbiota (GM), although this connection is still little understood. To assess APs effects on the GM of patients starting or ongoing treatment, a systematic review was carried out in PubMed and Scopus databases. Twelve articles were considered eligible for the review, which investigated the effects of risperidone (5 studies), quetiapine (3), amilsupride (1), olanzapine (1), and unspecified atypical drugs (2). Eleven reported changes in GM in response to APs, and associations between the abundance of bacterial groups and different metabolic parameters were described by most of them. However, the studies were noticeably heterogeneous considering design, methods, and results. In this way, the effects of APs on GM composition and diversity were inconclusive. Despite the uncertain interactions, a more comprehensive understanding on how microbiota is affected by APs may help to optimize treatment, potentially minimizing side effects and improving adherence to treatment.

The collection of microorganisms, mainly bacteria, which live in the gastrointestinal (GI) tract are collectible known as the gut microbiota. GI bacteria play an active role in regulation of the host's immune system and metabolism, as well as certain pathophysiological processes. Diet is the main factor modulating GI microbiota composition and recent studies have shown that high fat (HF) diets induce detrimental changes, known as dysbiosis, in the GI bacterial makeup. HF diet induced microbiota dysbiosis has been associated with structural and functional changes in gut-brain vagally mediated signaling system, associated with overeating and obesity. Although HF-driven changes in microbiota composition are sufficient to alter vagal signaling, it is unknown if restoring normal microbiota in obesity can improve gut-brain signaling and metabolic outcomes. In this study, we evaluated the effect of lean gut microbiota transfer in obese, vagally compromised, rats on gut-brain communication, food intake, and body weight. Male Sprague-Dawley rats were maintained on regular chow, or 45% HF diet for nine weeks followed by three weeks of microbiota depletion using an antibiotic cocktail. The animals were then divided into four groups (n=10 each): LF - control group on regular chow, LF-LF - chow fed animals that received antibiotics and microbiota from chow fed animals, HF-LF - HF fed animals that received microbiota from chow fed animals, and HF-HF - HF fed animals that received microbiota from HF fed animals. Animals were gavaged with donor microbiota for three consecutive days on week one and once a week thereafter for three more weeks. HF-LF animals received inulin as a prebiotic to aid the establishment of the lean microbiome.

We found that transferring a LF microbiota to HF fed animals (HF-LF) reduced caloric intake during the light phase when compared with HF-HF rats and prevented additional excessive weight gain. We did not observe significant changes in the density of vagal afferents terminating in the brainstem among the groups, however, HF-LF animals displayed an increase in postprandial activation of both primary sensory neurons innervating the GI tract and brainstem secondary neurons.

We concluded from these data that normalizing microbiota composition in obese rats improves gut-brain communication and restores normal feeding patterns which was associated with a reduction in weight gain.

This study aimed to identify characteristic gut genera in obese and normal-weight children (8-12 years old) using 16S rDNA sequencing. The research aimed to provide insights for mechanistic studies and prevention strategies for childhood obesity. Thirty normal-weight and thirty age- and sex-matched obese children were included. Questionnaires and body measurements were collected, and fecal samples underwent 16S rDNA sequencing. Significant differences in body mass index (BMI) and body-fat percentage were observed between the groups. Analysis of gut microbiota diversity revealed lower α-diversity in obese children. Di-fferences in gut microbiota composition were found between the two groups. Prevotella and Firmicutes were more abundant in the obese group, while Bacteroides and Sanguibacteroides were more prevalent in the control group.

To identify the characteristic gut genera in obese and normal-weight children (8-12-year-old) using 16S rDNA sequencing, and provide a basis for subsequent mechanistic studies and prevention strategies for childhood obesity.

Thirty each normal-weight, 1:1 matched for age and sex, and obese children, with an obese status from 2020 to 2022, were included in the control and obese groups, respectively. Basic information was collected through questionnaires and body measurements were obtained from both obese and normal-weight children. Fecal samples were collected from both groups and subjected to 16S rDNA sequencing using an Illumina MiSeq sequencing platform for gut microbiota diversity analysis.

Significant differences in BMI and body-fat percentage were observed between the two groups. The Ace and Chao1 indices were significantly lower in the obese group than those in the control group, whereas differences were not significant in the Shannon and Simpson indices. Kruskal-Wallis tests indicated significant differences in unweighted and weighted UniFrac distances between the gut microbiota of normal-weight and obese children (P < 0.01), suggesting substantial disparities in both the species and quantity of gut microbiota between the two groups. Prevotella, Firmicutes, Bacteroides, and Sanguibacteroides were more abundant in the obese and control groups, respectively. Heatmap results demonstrated significant differences in the gut microbiota composition between obese and normal-weight children.

Obese children exhibited lower α-diversity in their gut microbiota than did the normal-weight children. Significant differences were observed in the composition of gut microbiota between obese and normal-weight children.

Exercise, health, and the gut microbiota (GM) are strongly correlated. Research indicates that professional athletes, especially ultra-marathon runners, have unique GM characteristics. However, more research has focused on elite athletes, with little attention given to amateur sports enthusiasts, especially those in the middle-aged population. Therefore, this study focuses on the impact of long-term running on the composition and potential functions of the GM in middle-aged individuals.

We compared the GM of 25 middle-aged serious runnerswith 22 sedentary healthy controls who had minimal exercise habitsusing 16S rRNA gene sequencing. Additionally, we assessed dietary habits using a food frequency questionnaire.

Statistical analysis indicates that there is no significant difference in dietary patterns between the control group and serious runners. Diversity analysis results indicate that there is no significant difference in α diversity between the two groups of GM, but there is a significant difference in β diversity. Analysis of the composition of GM reveals that Ruminococcus and Coprococcus are significantly enriched in serious runners, whereas Bacteroides, Lachnoclostridium, and Lachnospira are enriched in the control group. Differential analysis of functional pathway prediction results reveals significant differences in the functional metabolism levels of GM between serious runners and the control group. Further correlation analysis results indicate that this difference may be closely related to variations in GM. In conclusion, our results suggest that long-term exercise can lead to changes in the composition of the GM. These changes have the potential to impact the overall health of the individual by influencing metabolic regulation.

The fecal microbiota plays an important role in maintaining animal health and is closely related to host life activities. In recent years, there have been an increasing number of studies on the fecal microbiota from birds. An exploration of the effects of species and living environments on the composition of gut microbiota will provide better protection for wildlife. In this study, non-injury sampling and 16S rDNA high-throughput sequencing were used to investigate the bacterial composition and diversity of the fecal microbiota in silver pheasants (Lophura nycthemera) and golden pheasants (Chrysolophus pictus) from Tianjin Zoo and Beijing Wildlife Park. The results showed that the abundance of Firmicutes was the highest in all fecal samples. At the genus level, Bacteroides was the common dominant bacteria, while there were some differences in other dominant bacteria genera. There were significant differences in fecal microbial composition between the golden pheasants from Tianjin Zoo and Beijing Wildlife Park. The metabolic analysis and functional prediction suggested that the gut microbiota composition and host metabolism were influenced by dietary interventions and living conditions. The results of this study provide the basis for further research of intestinal microbial of L. nycthemera and C. pictus, and valuable insights for conservation of related species.

The intestinal ecological environment plays a crucial role in nutrient absorption and overall well-being. In recent years, research has focused on the effects of extracellular vesicles (EVs) in both physiological and pathological conditions of the intestine. The intestine does not only consume EVs from exogenous foods, but also those from other endogenous tissues and cells, and even from the gut microbiota. The alteration of conditions in the intestine and the intestinal microbiota subsequently gives rise to changes in other organs and systems, including the central nervous system (CNS), namely the microbiome-gut-brain axis, which also exhibits a significant involvement of EVs. This review first gives an overview of the generation and isolation techniques of EVs, and then mainly focuses on elucidating the functions of EVs derived from various origins on the intestine and the intestinal microenvironment, as well as the impacts of an altered intestinal microenvironment on other physiological systems. Lastly, we discuss the role of microbial and cellular EVs in the microbiome-gut-brain axis. This review enhances the understanding of the specific roles of EVs in the gut microenvironment and the central nervous system, thereby promoting more effective treatment strategies for certain associated diseases.

Spirulina (S.) platensis is a blue-green algae with reported nutritional and health-promoting properties, such as immunomodulating, antioxidant, cholesterol-lowering properties, and beneficial effects on inflammatory diseases. Spirulina platensis can improve the function and composition of the gut microbiota and exert systemic beneficial effects. Gut dysbiosis is characterized by an imbalance in the composition and function of gut microbiota and is associated with several diseases. Some dietary bioactive compounds can restore the composition, diversity, and function of the gut microbiota and improve health-related parameters. This review proposes to gather relevant information on the effects of S. platensis supplementation on the modulation of the function and composition of gut microbiota and local and systemic measures related to gut health, such as inflammation, oxidative stress, and glucose and lipid metabolism. The body of evidence conducted with animals and clinical studies shows that S. platensis supplementation increased gut microbiota diversity and improved gut microbiota composition, as reported by a decrease in the Firmicutes/Bacteroides ratio, increase in the relative abundance of Prevotella and Lactobacillaceae, increase in short-chain fatty acid production and decrease of gut permeability. Improvements in gut microbiota have been associated with host health benefits such as anti-obesity, anti-diabetic, anti-hypertensive, anti-lipemic, anti-inflammatory, and antioxidant effects.

Patients with diabetes exhibit altered taste sensitivity, but its details have not been clarified yet. Here, we examined alteration of sweet taste sensitivity with development of glucose intolerance in Otsuka Long-Evans Tokushima Fatty (OLETF) rats as a model of non-insulin-dependent diabetes mellitus. Compared to the cases of Long Evans Tokushima Otsuka (LETO) rats as a control, glucose tolerance of OLETF rats decreased with aging, resulting in development of diabetes at 36-weeks-old. In brief-access tests with a mixture of sucrose and quinine hydrochloride, OLETF rats at 25 or more-weeks-old seemed to exhibit lower sweet taste sensitivity than age-matched LETO ones, but the lick ratios of LETO, but not OLETF, rats for the mixture and quinine hydrochloride solutions decreased and increased, respectively, aging-dependently. Expression of sweet taste receptors, T1R2 and T1R3, in circumvallate papillae (CP) was almost the same in LETO and OLETF rats at 10- and 40-weeks-old, while expression levels of a bitter taste receptor, T2R16, were greater in 40-weeks-old rats than in 10-weeks-old ones in both strains. There was no apparent morphological alteration in taste buds in CP between 10- and 40-weeks-old LETO and OLETF rats. Metagenomic analysis of gut microbiota revealed strain- and aging-dependent alteration of mucus layer-regulatory microbiota. Collectively, we concluded that the apparent higher sweet taste sensitivity in 25 or more-weeks-old OLETF rats than in age-matched LETO rats was due to the aging-dependent increase of bitter taste sensitivity in LETO rats with alteration of the gut microbiota.

Gastrointestinal (GI) microbiota plays an active role in regulating the host's immune system and metabolism, as well as certain pathophysiological processes. Diet is the main factor modulating GI microbiota composition and studies have shown that high fat (HF) diets induce detrimental changes (dysbiosis) in the GI bacterial makeup. HF diet induced dysbiosis has been associated with structural and functional changes in gut-brain vagally mediated signaling system, associated with overeating and obesity. Although HF-driven changes in microbiota composition are sufficient to alter vagal signaling, it is unknown if improving microbiota composition after diet-induced obesity has been established can ameliorate gut-brain signaling and metabolic outcomes. In this study, we evaluated the effect of lean gut microbiota transfer in obese, vagally compromised, rats on gut-brain communication, food intake, and body weight. Male rats were maintained on regular chow or 45% HF diet for nine weeks followed by three weeks of microbiota depletion using antibiotics. The animals were then divided into four groups (n = 10 each): LF - control fed regular chow, LF-LF - chow fed animals that received microbiota from chow fed donors, HF-LF - HF fed animals that received microbiota from chow fed donors, and HF-HF - HF fed animals that received microbiota from HF fed donors. HF-LF animals received inulin as a prebiotic to aid the establishment of the lean microbiome. We found that transferring a LF microbiota to HF fed animals (HF-LF) reduced caloric intake during the light phase when compared with HF-HF rats and prevented additional excessive weight gain. HF-LF animals displayed an increase in postprandial activation of both primary sensory neurons innervating the GI tract and brainstem secondary neurons. We concluded from these data that improving microbiota composition in obese rats is sufficient to ameliorate gut-brain communication and restore normal feeding patterns which was associated with a reduction in weight gain.

Psychiatric and mood disorders may play an important role in the development and persistence of irritable bowel syndrome (IBS). Previously, we hypothesized that stress-induced implicit memories may persist throughout life via epigenetic processes in the enteric nervous system (ENS), independent of the central nervous system (CNS). These epigenetic memories in the ENS may contribute to developing and perpetuating IBS. Here, we further elaborate on our earlier hypothesis. That is, during pregnancy, maternal prenatal stresses perturb the HPA axis and increase circulating cortisol levels, which can affect the maternal gut microbiota. Maternal cortisol can cross the placental barrier and increase cortisol-circulating levels in the fetus. This leads to dysregulation of the HPA axis, affecting the gut microbiota, microbial metabolites, and intestinal permeability in the fetus. Microbial metabolites, such as short-chain fatty acids (which also regulate the development of fetal ENS), can modulate a range of diseases by inducing epigenetic changes. These mentioned processes suggest that stress-related, implicit, long-term epigenetic memories may be programmed into the fetal ENS during pregnancy. Subsequently, this implicit epigenetic stress information from the fetal ENS could be conveyed to the CNS through the bidirectional microbiota-gut-brain axis (MGBA), leading to perturbed functional connectivity among various brain networks and the dysregulation of affective and pain processes.

Astaxanthin is a keto-based carotenoid mainly obtained from marine organisms, like Haematococcus pluvialis (H. pluvialis). Previous studies indicated the protective effects of Astaxanthin and H. pluvialis on aging related oxidative injury in liver, while the potential mechanisms are largely unknown. In addition, H. pluvialis residue is a by-product after astaxanthin extraction, which is rarely studied and utilized. The present study aimed to compare the effects of astaxanthin, H. pluvialis and H. pluvialis residue on the oxidant injury of liver in D-galactose-induced aging mice and explore the potential mechanisms through gut-liver axis. The results showed that all the three supplements prevented D-galactose-induced tissue injury, oxidative stress and chronic inflammation in liver and improved liver function. Gut microbiota analysis indicated that astaxanthin notably increased fecal levels of Bacteroidetes, unclassified_f__ Lachnospiraceae, norank_f__Lachnospiraceae, norank_f__norank_o__Clostridia_UCG-014, Prevotellaceae_ UCG-001, unclassified_f__Prevotellaceae in D-galactose-fed mice (p < 0.05). Compared to aging mice, H. pluvialis group had higher fecal levels of norank_f__Lachnospiraceae and Lachnospiraceae_UCG-006 (p < 0.05). H. pluvialis residue group displayed higher relative levels of Bacteroidetes, Streptococcus, and Rikenellaceae_RC9_gut_group (p < 0.05). Moreover, the production of fecal microbial metabolites, like SCFAs and LPS was also differently restored by the three supplements. Overall, our results suggest astaxanthin, H. pluvialis and H. pluvialis residue could prevent aging related hepatic injury through gutliver axis and provide evidence for exploiting of H. pluvialis residue as a functional ingredient for the treatment of liver diseases. Future studies are needed to further clarify the effect and mechanism of dominant components of H. pluvialis residue on liver injury, which is expected to provide a reference for the high-value utilization of H. pluvialis resources.