FRIDAY, Aug. 18, 2023 (HealthDay News) -- Race- and ethnicity-associated microbiome variation is identified at 3 months of age and persists throughout childhood, according to a study published online Aug. 17 in PLOS Biology.
Elizabeth K. Mallott, Ph.D., from Vanderbilt University in Nashville, Tennessee, and colleagues examined the age at which microbiome variability emerges between race and ethnic groups. Eight gut microbiome composition datasets from 2,756 samples, including 729 children between birth and 12 years of age, were combined.
The researchers found that variation in the gut microbiome associated with race and ethnicity occurred after 3 months of age and persisted throughout childhood. One-third of the bacterial taxa that vary across caregiver-identified racial categories in children are also reported to vary between adults. Racial and ethnic categories were identified with 87 percent accuracy with machine learning modeling of childhood microbiomes from the cohort studies. When childhood microbiomes were used to predict adult self-identified race and ethnicity, predictive genera were also among the top 30 most important taxa.
"Notably, our findings do not support race- or ethnicity-associated variation appearing at birth or shortly after, when mother-to-infant and other mechanisms of vertical microbial transmission are expected to be strongest," the authors write. "External factors are most likely shaping race- and ethnicity-associated microbiome variation at or shortly after 3 months."