Microbiome function and neurodevelopment in Black infants: Vitamin B12 biosynthesis emerges as a key factor

The early life gut microbiome affects the developing brain, and therefore may serve as a target to support neurodevelopment of children living in stressful and under-resourced environments, such as Black American youth. To date, microbiome compositions/functions key to facets of neurodevelopment have not been studied in Black children; thus, a subsample of Black infants living in urban, low-income neighborhoods whose mothers participated in a prenatal nutrition study were recruited for paired fecal microbiome (16S rRNA gene/shotgun metagenomics sequencing) and neurodevelopmental (standard testing, behavioral probes and maternal report) analysis. Two microbiome community types, defined by high Lachnospiraceae or Enterobacteriaceae abundance, were discovered in this cohort, and the Enterobacteriaceae-dominant community type was significantly associated with poorer cognitive/language scores specifically in male children. Vitamin B12 biosynthesis emerged as a key microbiome function, as it was the only pathway positively associated with all developmental skills (i.e., cognition, language, motor, surgency, effortful control, stress regulation).