South Asian Gut Microbiome Study Could Change How Lifestyle Diseases Are Treated

A new international study has found that the gut microbiome of South Asian populations follows distinct patterns shaped by local diet, geography, culture and lifestyle. The findings could eventually influence how conditions such as obesity, diabetes and cardiovascular disease are studied and treated in the region.

Published in the journal Gut Microbes, the research analysed gut microbiome data from 575 healthy adults across 10 culturally and geographically different communities in India and Sri Lanka. The study was carried out by researchers from the Birbal Sahni Institute of Palaeosciences, the University of Chicago and other institutions in India, Sri Lanka and the United States.

The researchers created the South Asian MicroBiome ARray, or SAMBAR, to build a larger reference dataset for South Asian populations. Participants provided stool samples along with information about their diet, lifestyle and health. The team then used DNA sequencing and statistical analysis to examine differences in the bacteria living in their digestive systems.

One of the study’s key findings was that gut microbiome changes associated with urbanisation were not identical across communities. Instead, each population appeared to follow its own microbiome trajectory. Geography and community background were stronger factors in determining microbiome composition than lifestyle alone.

The finding matters because much of the world’s existing microbiome research has focused on populations in Europe and North America. South Asians account for roughly a quarter of the world’s population but remain significantly underrepresented in global microbiome datasets. The researchers say the SAMBAR project helps address that gap by providing detailed data from adults living across diverse South Asian communities.

The researchers also identified associations between urbanisation and changes in certain gut bacteria. One example was Megamonas, which was associated with increased blood glucose and lower gut microbiome diversity in the study. The researchers also found changes involving microbial groups linked with wheat and dairy consumption in some communities. These findings are associations and do not establish that particular bacteria directly cause disease.

The study could become important as South Asia undergoes rapid urbanisation. Changes in food habits, physical activity, working patterns and exposure to processed foods are occurring alongside rising rates of obesity, type 2 diabetes and other cardiometabolic conditions.

For healthcare, the findings raise the possibility that microbiome-based diagnostics and personalised nutrition may eventually need to account for regional differences. A dietary or microbiome intervention developed using data from Western populations may not necessarily produce the same results in South Asian populations.

However, researchers caution that more work is required before microbiome findings can be translated into routine medical treatment. The current study provides a baseline rather than a ready-made treatment programme. Future research will need to examine how specific microbial changes interact with diet, genetics, environment and disease over time.

The SAMBAR dataset could support further studies into diabetes, obesity, cardiovascular disease and other lifestyle-related conditions. It could also help researchers compare communities as they move from traditional lifestyles towards increasingly urban environments.

For India, the research highlights a simple but important point: health recommendations do not always have to follow a one-size-fits-all model. Understanding how Indian diets, environments and lifestyles interact with the gut microbiome could eventually help researchers develop more locally relevant approaches to nutrition and preventive healthcare.