Khongkool K.Taweechotipatr M.Payungporn S.Sawaswong V.Lertworapreecha M.Mahidol University2026-06-212026-06-212026-07-01World Journal of Microbiology and Biotechnology Vol.42 No.7 (2026)09593993https://repository.li.mahidol.ac.th/handle/123456789/117441Probiotics provide strain-specific health benefits and may help protect against enteric pathogens. This study examined the protective effects of single- and multi-strain probiotics against Salmonella Typhimurium infection in a mouse model. Mice received Lactiplantibacillus plantarum TBRC-15420, Bacillus amyloliquefaciens TBRC-15434, Saccharomyces cerevisiae TBRC-19857, or a mixture of the three strains for 30 days before oral challenge with S. Typhimurium. Clinical outcomes, body weight change, pathogen clearance, histopathology, intestinal secretory IgA, and gut microbiota composition were then evaluated. No mortality was observed during the experiment, although infected mice showed transient clinical signs after challenge. Probiotic-treated mice lost less body weight than control mice, with the multi-strain treatment showing the most pronounced effect among the treatments tested and L. plantarum TBRC-15420 showing the strongest effect among the single-strain treatments. Intestinal sIgA values were descriptively higher in several probiotic-treated mice, particularly in the TBRC-15434 and TBRC-15420 groups. Probiotic treatment was also associated with lower S. Typhimurium recovery from the small intestine and reduced bacterial translocation to the liver and spleen, with no detectable bacteria in probiotic-treated groups by day five. Histological observations from representative sections suggested better-preserved intestinal, liver, and spleen architecture in probiotic-treated mice. Microbiome profiling showed descriptive compositional patterns, including relatively higher Bacteroidetes abundance and lower Proteobacteria abundance in several probiotic-treated groups. Overall, these findings suggest that native swine probiotics may help reduce S. Typhimurium burden and support host resilience during infection, although larger studies are needed to confirm the immune and microbiome-related effects.Biochemistry, Genetics and Molecular BiologyImmunology and MicrobiologyArticleSCOPUS10.1007/s11274-026-05077-82-s2.0-10504182859315730972