Probiotic properties of <i>Limosilactobacillus </i><i>fermentum</i> strain TPGMS1 isolated from gut microflora of <i>Tai-Phake</i> community of Assam

Probiotics confer health benefits in the host, such as antimicrobial activity, immune system modulation, reduce metabolic disorder and enhance anticancer activity. Most probiotic microorganisms belong to the Lactic Acid Bacteria (LAB) group. Human gut is a WHO/FAO recommended source for LAB. This study aimed to evaluate in vitro probiotic properties of LAB isolated from thehuman gut microflora of Tai-Phake community. Among 43 isolated LAB species, 26 were preliminarily selected for their antimicrobial activity. Isolates were evaluated for probiotic characteristics and antimicrobial activities against test microorganisms, Escherichia coli ATCC-10536 and Staphylococcus aureus ATCC-BAA-1026, using agar well-diffusion method. Eight of these isolates exhibited antagonistic activity against test microorganisms, which is indicated by zone of inhibition (ZoI) of 1.5 cm against Escherichia coliATCC-10536andZoI of 2.4 cm against Staphylococcus aureus ATCC-BAA-1026.The isolate with the best probiotic properties was identified using 16S rRNA sequencing as Limosilactobacillusfermentum strain TPGMS1. It exhibited high tolerance to low acidic condition (pH 2.0) and high bile salt (0.5% and 1%) concentrations, a significant hydrophobicity at 64 % and auto-aggregation of 58%. The results suggest that Limosilactobacillus fermentum strain TPGMS1 has high probiotic potential and can be further explored for probiotic formulation.