As South Asia's cities swell with millions of new arrivals, a landmark study of 575 adults across ten distinct communities reveals that the human gut is quietly registering every shift in diet, environment, and culture. Researchers from India, the United States, and Sri Lanka found that urbanization reliably reshapes the gut microbiome — but not in any single, universal way. The changes are as particular as the communities themselves, shaped by centuries of food tradition, geography, and daily life. In a field long dominated by data from European populations, this work places South Asian bodie