Genotypic and Phenotypic Characterization of a Novel Gut Bacterial Strain

Human gut microbiota is a complex ecosystem that plays a crucial role in maintaining metabolic balance, immune regulation, and gut homeostasis. Recent advances in microbiome research have shown its importance in various health conditions, particularly metabolic disorders such as obesity. Studies indicate that individuals with obesity have a significant decrease in beneficial bacterial species compared to lean individuals and a disrupted gut barrier function. The discovery of novel gut bacterial strains with functional properties relevant to host metabolism can provide insights into potential therapeutic applications for restoring microbial balance. The study aimed to characterize a novel gut bacterial strain, Strain-182, isolated from a healthy individual, and investigate its genomic and phenotypic properties to evaluate its adaptation to the gut environment and interactions with the human host. Whole genome sequencing and phylogenetic analysis were performed to determine the taxonomic placement and genetic features of Strain-182. A preliminary pangenome analysis identified unique genes related to metabolic activity, stress adaptation, and host interactions. In vitro assays were used to validate genomic analysis and further evaluate Strain-182 immunomodulation properties, short- chain fatty acid production, bile salts resistance and antimicrobial resistance, among other phenotypic traits. The results demonstrated that Strain-182 belonged to a recently discovered species, Luoshenia tenuis, which has previously been studied for its anti-obesity potential. The strain showed susceptibility to a wide range of antibiotics, was able to survive in high bile salt concentrations and showed potential for sporulation. In terms of its potential beneficial metabolic activity, it produced acetate as a major SCFA and exhibited lipolytic activity. However, Strain-182 did not show any bile salt hydrolase activity and did not induce or attenuate LPS-induced IL-8 production in enterocytes. The findings highlight the safety and survivability profile of Strain-182 and its potential for gut health-promoting effects, warranting further exploration of its therapeutic applications. Future studies will focus on validating these effects in vivo and in vitro potentially in combination with other strains, for assessing the role of Strain-182 in host health.