Ethnicity influences gut metabolites and microbiota of the tribes of Assam, India

Introduction The human gut microbes and their metabolites are involved in multiple host metabolic pathways. Dysbiosis in the gut microbiota and altered metabolite profiles were reported in diseased state. In a region like Assam, where 12.4% of the populations are tribal population, evaluating the influence of ethnicity on gut microbiota and metabolites has become important to further differentiate it from the diseased state. Objective To study the influence of ethnicity on fecal metabolite profile and their association with the gut microbiota composition. Methods In this study, we determined the untargeted fecal metabolites from five ethnic groups of Assam (Tai-Aiton, Bodo, Karbi, Tea-tribe and Tai-Phake) using GC-MS and compared them among the tribes for common and unique metabolites. Metabolites of microbial origin were related with the available metagenomic data on gut bacterial profiles of the same ethnic groups and functional analysis were carried out based on HMDB. Results The core fecal metabolite profile of the Teatribe contained aniline, benzoate and acetaldehyde. PLS-DA based on the metabolites suggested that the individuals grouped based on their ethnicity. PCA plot of the data on bacterial abundance at the level of genus indicated clustering of individuals based on ethnicity. Positive correlations were observed between propionic acid and the genus Clostridium (R = 0.43 and p = 0.03), butyric acid and the genus Lactobacillus (R = 0.45 and p = 0.024), acetic acid and the genus Bacteroides (R = 0.63 and p = 0.001) and methane and the genus Escherichia (R = 0.58 and p = 0.002). Conclusion Results of this study indicated that ethnicity influences both gut bacterial profile and their metabolites.