Exploring the probiotic landscape in understanding postbiotics from indigenous bacteria isolated from the stool samples of a tribal population at Mulluvadi village, Tamil Nadu, India.

Background: Urbanisation has been associated with a decline in the diversity of the gut microbiome that could potentially limit access to functionally robust probiotic strains. In contrast, traditional tribal populations represent underexplored reservoirs of diverse microbiota with unique metabolic capabilities. In this study, isolated and functionally characterised culturable probiotic bacteria from the gut microbiomes of individuals from the Mulluvadi tribal community (Tamil Nadu, India), with a focus on their inferred postbiotic-producing potential. Methods: A total of 112 microbial isolates were obtained from the stool samples of 25 healthy individuals, from which 13 representative bacterial strains were shortlisted by sequential screening based on phenotypic and functional criteria. These isolates were evaluated for tolerance to gastrointestinal stress conditions (pH, bile salts, NaCl, and temperature), cell surface hydrophobicity, auto-aggregation, safety attributes, and functional properties, including antibacterial activity, exopolysaccharide production, protease activity, biofilm formation, and short-chain fatty acid (SCFA) production. Results: The 13 isolates, mainly comprising Conclusion: Probiotic isolates from the gut microbiomes of a tribal population show remarkable postbiotic-producing capacity and potential functional relevance. These strains are promising candidates for further investigations toward the development of postbiotic-based functional formulations; however, their efficacies must be first established in animal and clinical trials and validated through additional