Bifidobacteria infantis and human milk oligosaccharides have independent effects on immune response and amino acid metabolism in germ-free mouse models

Mono-colonization with BI increased monocytes, macrophages, B cells, CD4+ T cells, and Treg cells in mesenteric lymph nodes (MLN) relative to control. In the spleen, BI alone increased B cells, dendritic cells, Th17 cells, and ILC3 cells, and enriched serum amino acid metabolism pathways. Additionally, BI influenced colonocyte gene expression, and modulated serum metabolites regulating circadian rhythms.

BI+HMO increased MLN Th17 cells and spleen monocytes compared to HMO alone. Collectively, the results of this study highlight the complex interplay between host-microbe-diet interactions and emphasize the importance of considering these interactions when designing strategies to modulate infant health during early life.