Gut microbiota in various childhood disorders: Implication and indications

Table 1 The microbiota in the different parts of the gut

       

Site	pH	Predominant microbiota	Bacterial load (CFU/gram content)	Other factors
Mouth	6.5-7	Bacteria (esp Fusobacterium nucleatum), fungi, viruses and protozoa	700 species	Ideal warm environment
Stomach	Strong acidic	Lactobacilli, streptococci, Lactobacillus, Peptostreptococcus, Helicobacter pylori, and yeasts	Low (102)	Gastric acidity, Acid suppressive therapy, H. pylori colonization, the reflux of bile, mucus thickness and gastric peristalsis
Duodenum	4-5	Lactobacilli and Streptococci	More than (102-104)	Age, diet, antibiotic, and proton pump inhibitor use
Jejunum-ileum	6-7.4	Firmicutes and Proteobacteria	More than duodenum (106-108)	Nutrient reach environment faster transit time, bile acids, and antimicrobial peptide exposure
Colon	Left colon 6.1-7.5; Cecum 5.7; Rectum 6.7	Bacteriodetes (especially the genera Bacteroides and Prevotella) and Firmicutes (especially members of the genus Clostridium). Methanogenic archaea and fungi; Cecum: Aerobic bacteria; Rectum: Bacteroides and Prevotella.	1010-1012	High diversity and density, no digestive secretions, nutrient-poor environment, & slow transit time (30 h)

H. pylori: Helicobacter pylori.

Table 2 The diseases-associated dysbiosis and the proposed probiotics

The disease	Encountered dysbiosis	The proposed probiotics
Autism[57,58]	Mother have abundance of Alphaproteobacteria, Proteobacteria, Acinetobacter, & Moraxellaceae. Children have more clostridial species, non-spore-forming anaerobes, and microaerophilic bacteria	No suggested type yet
Malnutrition[60]	Less Bifidobacteria. More pathogenic microbes (Escherichia coli, Fusobacterium mortiferum, & Streptococcus spp.)	The lack of strong evidence for specific types of probiotics
Obesity[75-78]	Less bifidobacteria. More Bacteroides & Staphylococcus spp.	Bifidobacterium lactis and Lactobacillus GG
Infant colic[85-87]	More abundance of Proteobacteria. Less abundance of the genera Lactobacillus & Bifidobacterium. Reduced gut bacterial diversity	Lactobacillus reuteri DSM17938 in breastfeeding infants
Functional abdominal pain[90,91]	More Prevotella, Lactobacillus, Veillonella, & Parasporo bacterium. Less Verrucomicrobium & Bifidobacterium	Sporobacter & Subdoligranulum
Functional constipation[94,95]	More Prevotella. More butyrate-producing bacteria as Roseburia, Coprococcus, & Faecalibacterium	Still investigational
Necrotizing enterocolitis[98,99]	More Citrobacter koseri and/or Klebsiella pneumoniae. Reduced diversity. Less Lactobacillus abundance	Bifidobacteria and Lactobacillus
Helicobacter pylori infection[102,106,107]	Prevotella, Clostridium, Proteobacteria, and Firmicutes. Less Bacteroides	Saccharomyces boulardii, L. acidophilus, L. casei DN-114001, L. gasseri, and Bifidobacterium infantis 2036 and Lactobacillus reuteri Gastrus
Coeliac disease[109,114-116]	Reduced Gram-positive/Gram-negative bacteria ratio. Less Bifidobacterium, Clostridium histolyticum, Clostridium. lituseburense and Faecalibacterium prausnitzii. More Bacteroides-Prevotella group. Less IgA coating the Bacteroides-Prevotella group	Lactobacillus rhamnosus, Bifidobactera breve & Longum, and Lactobacilli strains (L. ruminis, L. Johndoni, L. amylovorus, L. salivaris)
Inflammatory bowel diseases[122,126-128]	Less abundance of the healthy commensal (such as Clostridium IXa and IV groups, Bacteroides, Bifidobacteria). More abundance of the pathogenic bacteria as sulphate-reducing Escherichia coli	Still controversial. Saccharomyces boulardi. Escherichia coli Nissle1917, Bifidobacterium breve, Bifidobacterium bifidum, Lactobacillus acidophilus
Cystic fibrosis[135-137]	Aberrant colonization of gut and respiratory microbiota due to altered intestinal & airway microenvironment	Lactobacillus rhamnosus GG & Lactobacillus reuteri
Allergic rhinitis[140,142-144]	Decrease gut bacterial diversity	Lactobacillus paracasei. Bifidobacteria mixture
Bronchial asthma[147]	Relative abundance of the bacterial genera Rothia, Veillonella, Lachnospira, & Faecalibacterium. Low total & gut microbial diversity	Still controversial
Atopic dermatitis[154-157]	Reduced microbial diversity. More abundance of pathogenic Staphylococcus aureus and Malassezia. Presence of Clostridioides difficile. More Bifidobacteria abundance. Lower lactobacilli abundance	Topical Roseomonas mucosa
Psoriasis[160,161,163,164]	More bacterial diversity & heterogeneity. More Staphylococcus aureus. Less Staphylococcus epidermidis & Propionibacterium acnes. Reduced microbiota stability. Variable topographic dysbiosis	Sill controversial. Oral Lactobacillus, one sachet thrice daily with biotin
Systemic lupus erythematosus[166,168]	Less microbiota abundance and diversity	Animal studies showed Lactobacillus fermentum CECT5716 (LC40)
Juvenile idiopathic arthritis[172,174]	Less Faecalibacterium Prausnitzii abundance. More Bifidobacterium abundance, mostly B. adolescentis	Not conclusive. Trial with Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus bulgaricus, Lactobacillus rhamnosus, Bifidobacterium breve, Streptococcus thermophile & Bifidobacterium longum
Dental caries[176,178,179]	More abundance of Prevotella melaninogenica, Leptotrichia shahii, Leptotrichia HOT 498, Veillonella dispar, and Streptococcus mutans	Insufficient evidence. Lactobacillus rhamnosus may help
Chronic congestive heart failure[180,184,187,189]	Decreased gut microbiota diversity. More pathogenic Microbes as Campylobacter, Yersinia enterocolitica, Salmonella, Shigella & candida. Low Coriobacteriaceae, Erysipelotrichaceae and Ruminococcaceae	Bifidobacteria, yeasts, and lactic acid-producing bacteria such as Lactobacillus rhamnosus GR-1. Saccharomyces boulardii