Effects of prenatal consumption of caprine milk oligosaccharides on mice mono-associated with Bifidobacterium bifidum (AGR2166)

Background. Prenatal consumption of oligosaccharides are associated with changes in the maternal gastrointestinal tract (GIT) microbiota with health consequences for the offspring. It has previously been demonstrated that caprine milk oligosaccharides (CMO) stimulate the growth and fermentation rate of Bifidobacterium bifidum AGR2166. Objective. The objective of this study was to examine the effects of B. bifidum AGR2166 and prenatal consumption of CMO, alone or in combination, on the dam’s large intestine, foetal development and ability of B. bifidum to translocate from the gastrointestinal lumen to organs and foetal membranes. Method. Germ-free BALB/c mice, inoculated with B. bifidum AGR2166 or anaerobic phosphate buffer, were fed either diet supplemented with CMO or with galacto-oligosaccharide. Pregnant mice were euthanised 1 to 3 days before the expected delivery date and samples collected for analysis. Results. Dietary CMO, regardless of bifidobacterial inoculation was shown to increase GIT weight and to reduce foetal weight compared to galacto-oligosaccharide-fed dams. B. bifidum AGR2166 DNA was detected in the mesenteric lymph nodes, liver, plasma and placenta of the dam by amplification of the bifidobacterial 16S rRNA gene. Conclusion: B. bifidum AGR2166 DNA was detected in maternal organs, however there is no indication that live bifidobacteria was able to translocate during pregnancy. Further studies using conventionally-raised mouse models will develop a deeper understanding of the interactions between dietary CMOF, the host, and bacteria.