Associations between fiber intake and gut microbiota composition in New Hampshire Hispanic/Latino adults at risk for food insecurity

Recent advances in genetic sequencing have enabled investigations into the composition and functional capacity of the complex ecosystem of resident microorganisms of the human gastrointestinal tract (the gut microbiome). Studies have additionally found associations between dietary pattern (particularly fiber intake), gut microbiome composition, and health status of the host, including weight status and risk of chronic disease, but certain demographic groups are underrepresented in this literature. Hispanics/Latinos are the largest minority population in the United States and in New Hampshire, and are disproportionately affected by chronic metabolic disease, low fiber intake, and food insecurity, but gut microbiome characteristics of this population remain understudied. This investigation characterized associations between dietary fiber intake and gut microbiome composition in a population of 60 Hispanic/Latino adults eligible for federal food assistance residing in New Hampshire. Daily fiber intake was assessed using the National Health and Nutrition Examination Survey Dietary Screener Questionnaire. Microbiome composition data were derived from 16S ribosomal RNA gene sequencing of participant fecal samples. Partial correlations and analysis of covariance were used to evaluate and characterize associations between fiber intake and within-subject alpha microbial diversity. Covariate adjustments were made to control for confounding variables such as age. This study provides novel data on the relationship between fiber intake and gut microbiome diversity in this fast-growing yet understudied population. These findings will inform the development of targeted interventions to improve the health of this population through beneficial changes to the microbiome mediated by dietary changes and greater access to fiber-rich foods.