Gut Microbiota Diversity across Ethnicities in the United States

Abstract

32Composed of hundreds of microbial species, the composition of the human gut 33 microbiota can vary with chronic diseases underlying health disparities that 34 disproportionally affect ethnic minorities. However, the influence of ethnicity on the gut 35 microbiota remains largely unexplored and lacks reproducible generalizations across 36 studies. By distilling associations between ethnicity and differences in two United States 37 based 16S gut microbiota datasets including 1,673 individuals, we report 12 microbial 38 genera and families that reproducibly vary by ethnicity. Interestingly, a majority of these 39 microbial taxa, including the most heritable bacterial family, Christensenellaceae, overlap 40 with genetically-associated taxa and form co-occurring clusters linked by similar 41 fermentative and methanogenic metabolic processes. These results demonstrate recurrent 42 associations between specific taxa in the gut microbiota and ethnicity, providing hypotheses 43 for examining specific members of the gut microbiota as mediators of health disparities. 44Here, we comprehensively examine connections between self-declared ethnicity and 68 gut microbiota differences across more than a thousand individuals sampled by the 69 American Gut Project (AGP, N=1375) (24) and the Human Microbiome Project (HMP, N=298) 70 (6). Previous studies demonstrated that human genetic diversity in the HMP associates with 71 differences in microbiota composition (25), and genetic population structure within the HMP 72 generally delineates self-declared ethnicity (20). Ethnicity was not found to have a 73 significant association with microbiota composition in a Middle Eastern population, 74 however factors such as lifestyle and environment that influence microbiota variation across 75 participants was homogenous compared to the ethnic, sociocultural, economic, and dietary 76 diversity found within the United States (26). While ethnic diversity is generally 77 underrepresented in current microbiota studies, evidence supporting an ethnic influence on 78 microbiota composition among first generation immigrants has been recently demonstrated 79 in a Dutch population (27). The goal of this examination is to evaluate, for the first time, if 80 there are reproducible differences in gut microbiota across ethnicities within an overlapping 81 United States population, as ethnicity is one of the key defining factors for health disparity 82 incidence in the United States. Lifestyle, dietary, and genetic factors all vary to different 83 degrees across ethnic groups in the United States, and it will require more even sampling of 84 ethnic diversity and stricter phenotyping of study populations to disentangle which factors 85 underlie ethnic microbiota variation in the AGP and HMP. 86 6 Results: 87 Microbiota are subtly demarcated by ethnicity 88We first evaluate gut microbiota distinguishability between AGP ethnicities (Fig 1A, 89 family taxonomic level, Asians-Pacific Islanders (N=88), Caucasians (N=1237), Hispanics 90 (N=37), and African Americ...

The Infant Gut Resistome is Associated with E. coli and Early-life Exposures

“…The NHBCS includes primarily White women and their infants from New Hampshire and Vermont in the United States. Thus, our results may not be generalizable to other communities with different ethnic [50] or geographic compositions [30]. Most variables were collected via standardized medical record review including age, sex, delivery mode, and antibiotic exposures reducing multiple possible biases.…”

Gut microbiota and cardiovascular disease: opportunities and challenges

“…Ethnicity differences, though often overlooked in studies, are known to affect hypercholesterolemia and CAD development. Ethnicity differences can capture biological variations derived from social, economic, and cultural differences, human genetic variation, and biogeographical ancestry divergences, as well as lifestyle and dietary differences [183]. Risk factors of CAD development including smoking, blood pressure, obesity, and cholesterol can also vary among different ethnicity groups [184,185], resulting in certain groups having an earlier onset and worse outcomes of CAD.…”

“…In addition, African Americans also have a diet with relatively higher sugar, higher sodium, and lower potassium [187] contents that can lead to higher blood pressure. In addition, ethnicity and dietary differences are associated with variations in microbial composition and abundance [181,189,190] and even more strongly with gut microbiota than other factors such as genetics [191], age, sex, and BMI [183]. For example, comparative studies of the microbiome in rural and urban areas in healthy individuals have reported that populations residing in non-Western and/or rural areas have a higher bacterial diversity when compared with populations in America and Europe [162,192].…”

Decoding the Language of Microbiomes: Leveraging Patterns in 16S Public Data using Word-Embedding Techniques and Applications in Inflammatory Bowel Disease

“…In another approach, taxa can be categorized, or binned, by their phylogenetic relationships (e.g. all taxa that share a family are analyzed as one unit) (37,38). Such binning methods may obscure meaningful biological signal, and are also heavily database dependent not all microbes are clearly classified by taxonomy.…”