Decoding the Microbial Diversity of Indian Fermented Foods: Integrating Ethnobiology, Multi-Omics and Functional Insights.

India's diverse culinary heritage includes a wide spectrum of traditional fermented foods that harbour complex microbial communities essential for flavour development, preservation, and nutritional enhancement. These microorganisms-primarily lactic acid bacteria, yeasts, and molds-contribute functional properties that extend beyond food transformation to confer health benefits, including probiotic potential and metabolic regulation. This review integrates classical microbiological studies with modern molecular approaches such as metagenomics, metatranscriptomics, and metabolomics to elucidate the microbial diversity of Indian fermented foods. It highlights how geography, substrates, and ethnic traditions shape region-specific microbial consortia sustained through long-standing ethno-microbiological practices. Special focus is given to the glycemic modulation achieved through microbial fermentation, wherein organic acid production and resistant starch formation lower glycemic index and improve glucose metabolism. These processes, along with enhanced nutrient bioavailability, vitamin synthesis, and immunomodulation, illustrate the broader functional potential of fermentation. The review also examines interactions between food-borne microbes and the human gut microbiota, underscoring implications for personalized nutrition. Finally, it discusses modernization and commercialization strategies and outlines future directions involving multi-omics integration, indigenous starter cultures, and microbiome-based innovations to harness India's microbial heritage for improved health and sustainable food development.