Microbiota Supplementation with <i>Bifidobacterium</i> and <i>Lactobacillus</i> Modifies the Preterm Infant Gut Microbiota and Metabolome: An Observational Study.

Abstract

Supplementation with members of the early-life microbiota as "probiotics" is increasingly used in attempts to beneficially manipulate the preterm infant gut microbiota. We performed a large observational longitudinal study comprising two preterm groups: 101 infants orally supplemented with <i>Bifidobacterium</i> and <i>Lactobacillus</i> (Bif/Lacto) and 133 infants non-supplemented (control) matched by age, sex, and delivery method. 16S rRNA gene profiling on fecal samples (n = 592) showed a predominance of <i>Bifidobacterium</i> and a lower abundance of pathobionts in the Bif/Lacto group. Metabolomic analysis showed higher fecal acetate and lactate and a lower fecal pH in the Bif/Lacto group compared to the control group. Fecal acetate positively correlated with relative abundance of <i>Bifidobacterium,</i> consistent with the ability of the supplemented <i>Bifidobacterium</i> strain to metabolize human milk oligosaccharides into acetate. This study demonstrates that microbiota supplementation is associated with a <i>Bifidobacterium</i>-dominated preterm microbiota and gastrointestinal environment more closely resembling that of full-term infants.