Ethnicity, geography, and dietary habits are known to have dominant roles in modulating the gut microbiota. Two major ethnic groups Ahom and Bodo in the north-east of India consume traditionally prepared rice beer which contains various microbes and substances that promote the growth of such microbes, known as prebiotics. This study aimed to understand the effect of traditionally prepared rice beer on gut microbiota. A total of 134 (67 from each group) volunteers including non-drinkers and drinkers from three locations were recruited. Fecal and blood samples were collected to study fecal bacterial and metabolite profiles and biochemical markers, respectively. Amplicon 16S rRNA gene sequencing (region V3–V4) by next-generation sequencing showed similar alpha and beta diversities in both the ethnic groups. However, with rice beer consumption the abundance of Firmicutes, Bacteroidetes, Fusobacteria phyla was higher in the drinkers (p < 0.05) of Ahom whereas only Firmicutes were higher in Bodo ethnic group. At the genus level, the bacterial abundance of Faecalibacterium and Roseburia were lower in the drinkers (p < 0.05) of both communities. Gas chromatography–mass spectrometry for the detection of fecal metabolites also revealed lower butyric acid in the feces of drinkers (p < 0.05). This study showed the effects of traditionally prepared rice beer on human gut microbiota and fecal metabolites. Further research is required to understand their effect on health.

众所周知，种族、地理和饮食习惯在调节肠道微生物群方面发挥着主导作用。印度东北部的两个主要民族阿霍姆族和博多族饮用传统酿造的米啤酒，其中含有各种微生物和促进此类微生物生长的物质，称为益生元。本研究旨在了解传统制备的米啤酒对肠道微生物群的影响。总共招募了 134 名志愿者（每组 67 名），包括来自三个地点的不饮酒者和饮酒者。收集粪便和血液样本，分别研究粪便细菌和代谢物谱以及生化标志物。通过新一代测序进行的扩增子 16S rRNA 基因测序（V3-V4 区）显示，两个种族群体中存在相似的 α 和 β 多样性。然而，随着米酒的消耗，阿霍姆族饮用者中厚壁菌门、拟杆菌门、梭杆菌门的丰度较高（p  <0.05） ，而博多族群中仅厚壁菌门丰度较高。在属水平上，两个群落的饮酒者中粪杆菌和罗斯布里亚菌的细菌丰度均较低（p  < 0.05）。用于检测粪便代谢物的气相色谱-质谱法也显示饮酒者粪便中丁酸含量较低（p  < 0.05）。这项研究显示了传统制备的米酒对人体肠道微生物群和粪便代谢物的影响。需要进一步的研究来了解它们对健康的影响。