Exploring new Bacteroidota strains: Functional Diversity and Probiotic Characteristics

Bacteroidota, a diverse phylum of bacteria, are increasingly recognized for their significant contributions to host health, particularly through their antimicrobial and probiotic properties. This study investigates the functional diversity and probiotic potential of 42 new Bacteroidota strains enriched and identified from diverse hosts, including mouse ceca and human stool samples. Using 16S rRNA gene sequencing, we phylogenetically characterized the strains of the genera Bacteroides, Phocaeicola and Sphingobacterium and assessed their functional properties related to probiotic potential. The strains were evaluated concerning their ability to inhibit biofilm formation of WHO declared clinically significant pathogens, including gram-positive Staphylococcus aureus and Staphylococcus epidermidis , gram-negative Klebsiella oxytoca and Pseudomonas aeruginosa , and the eukaryotic fungus Candida albicans. Additionally, we investigated bile salt hydrolase and quorum quenching activities of the strains, key traits associated with probiotic efficacy. Our findings demonstrate that all examined Bacteroidota strains consistently exhibit a capacity to inhibit biofilm formation but to different extent. Furthermore, 14 strains showed quorum quenching activity, and 39 bile salt hydrolase activity, highlighting their probiotic potential. High biofilm inhibition as well as quorum quenching activity against both autoinducers, AHL and AI-2, were predominantly observed in Bacteroides caecimuris and Bacteroides muris , making them attractive candidates for next-generation probiotics. Overall, this study advances the field of next-generation probiotics by identifying promising candidates for therapeutic applications potentially revolutionizing approaches to microbiome-based interventions and pathogen control in clinical settings.