Why diversity matters in the human microbiome sciences
Human genomes are 99.9% identical, yet gut microbiomes and viromes are remarkably individualized. This microbiome variation may underpin individual differences in gut health and disease, including health disparities whose causes are often unknown. Unfortunately, the vast majority of characterized human microbiomes are from participants of European ancestry. This bias limits our understanding of the diversity of human microbiomes and viromes across the diversity of all of us. Relative to BMI, sex, or age, our studies find that self-identified race and ethnicity is an important factor persistently associated with microbiome variation across studies. The distinguishing aspects of the variation span bacterial and viral taxa and gene functions spanning carbohydrate active enzymes and antibiotic resistance. Notably, geography and diet were not sufficient to explain the variation across self-identity groups. Disentangling microbiome diversity across the diversity of humans is an important imperative for potentially modulating and/or predicting social and environmental factors and microbiome compositions that might contribute to the onset and/or prevention of health disparities.