A distinct clade of Bifidobacterium longum in the gut of Bangladeshi children thrives during weaning

The gut microbiome has an important role in infant health and development. We characterized the fecal mi-crobiome and metabolome of 222 young children in Dhaka, Bangladesh during the first two years of life. A distinct Bifidobacterium longum clade expanded with introduction of solid foods and harbored enzymes for utilizing both breast milk and solid food substrates. The clade was highly prevalent in Bangladesh, present globally (at lower prevalence), and correlated with many other gut taxa and metabolites, indicating an impor-tant role in gut ecology. We also found that the B. longum clades and associated metabolites were implicated in childhood diarrhea and early growth, including positive associations between growth measures and B. longum subsp. infantis, indolelactate and N-acetylglutamate. Our data demonstrate geographic, cultural, seasonal, and ecological heterogeneity that should be accounted for when identifying microbiome factors implicated in and potentially benefiting infant development.

Automated summary

This study investigated the gut microbiome and metabolome of 222 young children in Dhaka, Bangladesh during the first two years of life. It found that a specific Bifidobacterium longum clade expanded after the introduction of solid foods and had enzymes for utilizing both breast milk and solid food substrates. The clade was prevalent in Bangladesh, present globally (at lower prevalence), and correlated with other gut taxa and metabolites, indicating its important role in gut ecology.