Published online Jul 21, 2022. doi: 10.3748/wjg.v28.i27.3455
Peer-review started: February 18, 2022
First decision: May 9, 2022
Revised: May 17, 2022
Accepted: June 20, 2022
Article in press: June, 20, 2022
Published online: July 21, 2022
Processing time: 150 Days and 6.8 Hours
Dyslipidemia is a common chronic disorder, and is defined as any abnormality in blood lipid levels. In recent years, considerable progress has been made in elucidating the mechanisms of dyslipidemia, and the gut microbiota (GM) has been indicated to play a pivotal role in its pathophysiology. However, the associations between GM and dyslipidemia remain to be elucidated.
Although recent studies have convincingly linked GM to dyslipidemia, proving the associations between GM and host lipid metabolism remains a challenge in humans. In addition, ethnicity, geography and sex are potent factors that could influence the GM community. Therefore, it is important to clarify the relationship between GM and dyslipidemia, and to explore the importance of sex differences. In this study, we first revealed sex differences regarding the GM features, and then introduced dyslipidemia, highlighting its intricate relationships with GM and possible altered GM functions.
This study focused on the associations of GM features with dyslipidemia based on sex differences in a northwestern Chinese population.
This study finally recruited 142 participants (73 females and 69 males) at Honghui Hospital, Xi’an Jiaotong University, who fulfilled the criteria for the diagnosis of dyslipidemia according to the “Guidelines for prevention and treatment of dyslipidemia in Chinese adults”. The anthropometric and blood metabolic parameters of all participants were measured. According to their detected serum lipid levels, female and male participants were classified into a high triglyceride (H_TG) group, a high total cholesterol (H_CHO) group, a low high-density lipoprotein cholesterol (L_HDL-C) group, and a control (CON) group with normal serum lipid levels. Fresh fecal samples were collected for 16S rRNA gene sequencing, and UPARSE software, QIIME software, the RDP classifier tool and the FAPROTAX database were used for sequencing analyses.
Different GM features were identified between females and males, and the associations between GM and serum lipid profiles were different between females and males. In the comparison of the three dyslipidemia subgroups in females, Lactobacillus_salivarius were enriched in H_CHO females, and Prevotellaceae were enriched in L_HDL-C females. Compared with CON or H_TG males, Prevotellaceae, unidentified_Ruminococcaceae, Roseburia and Roseburia_inulinivorans were decreased in L_HDL-C males; while linear discriminant analysis effect size analysis indicated an enrichment of these above GM taxa in H_TG males in comparison to other male subgroups. Additionally, Roseburia_inulinivorans abundance was positively correlated with the serum TG and total cholesterol levels, and Roseburia were positively correlated with the serum TG level. Furthermore, Proteobacteria, Lactobacillaceae, Lactobacillus and Lactobacillus_salivarius distinguished H_CHO females from CON females, while Coriobacteriia, Coriobacteriales, Prevotellaceae, Roseburia and Roseburia_inulinivorans distinguished H_TG males from CON males. Based on the predictions of GM metabolic capabilities from the FAPROTAX database, cellulolysis was increased in L_HDL-C females compared with CON females, but was decreased in L_HDL-C males compared with CON males.
This study provides evidence of the associations between GM and serum lipid profiles based on sex differences, suggesting a complex interaction between GM and distinct lipid metabolisms, and providing new insights into the pathogenesis of dyslipidemia.
Future studies are needed to determine which specific taxa have the potential to ameliorate dyslipidemia, to investigate the underlying biological functions of the key GM in dyslipidemia, and to explore the differences in diet and other factors between females and males as possible causes for the observed differences in GM and the lipid profiles.