Human microbiome variation associated with race and ethnicity emerges as early as 3 months of age

Area of Science:

• Human microbiome research
• Developmental biology
• Health disparities

Background:

• Human microbiome composition is linked to disease incidence, prevalence, and mortality.
• Microbiome variation is known to associate with race and ethnicity in the United States.
• The specific age at which these race and ethnicity-associated microbiome differences emerge in early life is not well understood.

Purpose of the Study:

• To determine the age of onset for race and ethnicity-associated gut microbiome variation in children.
• To investigate the persistence of these variations through childhood.
• To identify key microbial taxa and developmental windows influencing these associations.

Main Methods:

• Analysis of gut microbiome data from 729 children across 8 cohort studies (2,756 samples).
• Utilized machine learning models to distinguish racial and ethnic categories based on childhood microbiomes.
• Compared bacterial taxa varying in children with those known to vary in adults.

Main Results:

• Race and ethnicity-associated gut microbiome variation emerges after 3 months of age and continues through childhood.
• Machine learning accurately distinguished racial and ethnic groups (87% accuracy) using childhood microbiome data.
• Taxa predictive of race/ethnicity in children were also important for predicting adult race/ethnicity.

Conclusions:

• A critical developmental window at or shortly after 3 months of age is identified for the establishment of race and ethnicity-associated microbiome patterns.
• Social and environmental factors likely drive these early microbiome variations.
• These early-life microbiome differences may contribute to adult health outcomes and health disparities.