GOS-fed mice Targeted Locus (Loci). mouse gut metagenome

Prebiotics are carbohydrates resistant to gastrointestinal digestive enzymes that can be fermented by colonic health-promoting bacteria, modulating the intestinal microbiota. The aim of this study was to evaluate the influence of a β (1-4) galacto-oligosaccharides formulation consisting of 90% pure GOS (GOS-90), on the composition and activity of the mouse gut microbiota. Germ-free mice were colonized with microbiota from four pathogen-free wt 129 mice donors (SPF), and stools were collected during a feeding trial in which GOS-90 was delivered orally for 14 days. Pyrosequencing of 16S rDNA amplicons showed that Bifidobacterium and specific Lactobacillus, Bacteroides and Clostridiales were more prevalent in GOS-90-fed mice after 14 days, although the prebiotic impact on Bifidobacterium varied among individual mice. Prebiotic feeding also resulted in decreased abundance of Bacteroidales, Helicobacter and Clostridium. High-throughput quantitative PCR showed an increased abundance of Bifidobacterium adolescentis, B. pseudocatenulatum, B. lactis and B. gallicum in the prebiotic fed mice. Regardless of treatment, female mice showed a higher diversity (Phylogenetic Diversity PD = 15.1 ± 3.4 in stools and PD = 13.0 ± 0.6 in intestinal contents) than males (PD = 7.8 ± 1.6 in stool samples and PD = 9.5 ± 1.0 in intestinal contents), and significant differences in abundance of bacterial genera were observed between genders. GOS-90 did not modify inflammatory biomarkers (IL-6, IL-12, IL-1β, IFN-γ and TNF-α). Decreased butyrate, acetate and lactate concentrations in stools of prebiotic fed mice suggested an increase in colonic absorption and reduced excretion. Overall, our results demonstrate that GOS-90 is capable of modulating the intestinal microbiome resulting in expansion of the probiome (autochtonous commensal intestinal bacteria considered to have a beneficial influence on health).