Neighborhood-level socioeconomic disadvantage is associated with gut microbial composition and diversity across many chronic disease states.

Background: Socioeconomic disparities play a major role in health and disease. Growing evidence suggests that healthcare access accounts for only part of these outcomes, and additional biological mechanisms remain to be elucidated. The gut microbiome is a central component of health and disease and can be affected by environmental factors and socioeconomic disparities. Methods: Using a large cohort with diverse comorbidities identified in the Elixhauser comorbidity index, we tested for association between area deprivation index (ADI), a neighborhood-level measurement of socioeconomic disadvantage in the United States, and taxonomic profiles of gut microbiota (16S rRNA gene sequences) to examine the effect of (1) covariates (age, sex, and smoking), ADI, and microbiota on comorbidities and (2) covariates, ADI, and comorbidities on microbiota. Findings: Covariates explained several associations, and ADI was associated with multiple comorbidities as assessed using generalized linear models (GLMs) augmented with ADI regression splines. Most associations with ADI were nonlinear, and the associations were most frequent among individuals living in more disadvantaged neighborhoods. Multivariate analysis of variance (MANOVA) revealed a significant effect of ADI on the collective microbiota of the cohort. Individual microbial taxa were identified in association with ADI, ranging from potentially more beneficial to human health to more disease-promoting, whereas microbial diversity was negatively associated with over half of the disease associations. Interpretation: These findings indicate that ADI is associated with alterations to the gut microbiome and common disease states.