BackgroundUrbanisation 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.MethodsA 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.ResultsThe 13 isolates, mainly comprising Lactiplantibacillus plantarum and Lacticaseibacillus rhamnosus, exhibited >70% survival under simulated gastric and biliary conditions, high levels of hydrophobicity (60%–80%), strong inhibition of pathogens (12–25 mm), significant production of SCFAs, high levels of protease activity (15–20 mm clearance), and marked membrane stabilising effects of human red blood cells (65%–82%). All isolates were non-haemolytic, negative for DNase production, and displayed safety profiles consistent with those of probiotics. In particular, L. plantarum and Heyndrickxia coagulans were identified as the most functionally potent strains.ConclusionProbiotic 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 in vivo and clinical studies for gut dysbiosis and other related disorders.