Modulating the developing gut microbiota with 2fucosyllactose and pooled human milk oligosaccharides

Synthetic human milk oligosaccharide (HMO) structures are used to supplement infant formula despite limited understanding of their impact on the developing gut microbiota. Here, we assess the impact of 2fucosyllactose (2FL) and pooled (p)HMOs on the composition and activity of cultured microbial communities derived from seven infants. Bacterial isolates spanning 157 species were derived from these communities and individually evaluated for their responses to HMOs. Exposure to pHMOs resulted in shifts in the composition and metabolic output of the communities, including increased absolute abundance of several genera, notably Bacteroides, and production of health-associated metabolites. In contrast, the addition of 2FL alone had no measurable effect. Over 100 non-Bifidobacterium species showed enhanced growth with pHMOs treatment, and a high degree of intraspecies variation in HMO metabolism was noted. Our study warrants further investigation into the significance of incorporating 2FL alone into infant formula, especially in the context of gut microbiota modulation.