Evaluation of the Immunomodulatory Activities of the Probiotic Strain Lactobacillus fermentum UCO-979C

UCO-979C, a strain isolated from a human stomach, was previously characterized by its potential probiotic properties. The UCO-979C strain displayed the ability to beneficially regulate the innate immune response triggered by infection in human gastric epithelial cells. In this work, we conducted further studies in intestinal epithelial cells (IECs) and experiments in mice in order to characterize the potential immunomodulatory effects of UCO-979C on the intestinal mucosa. Results demonstrated that the UCO-979C strain is capable to differentially modulate the immune response of IECs triggered by Toll-like receptor 4 (TLR4) activation through the modulation of TLR negative regulators' expression. In addition, we demonstrated for the first time that UCO-979C is able to exert its immunomodulatory effect in the intestinal mucosa . The feeding of mice with UCO-979C significantly increased the production of intestinal IFN-γ, stimulated intestinal and peritoneal macrophages and increased the number of Peyer's patches CD4 T cells. In addition, UCO-979C augmented intestinal IL-6, reduced the number of immature B220 CD24 B cells from Peyer's patches, enhanced the number of mature B B220 CD24 cells, and significantly increased intestinal IgA content. The results of this work revealed that UCO-979C has several characteristics making it an excellent candidate for the development of immunobiotic functional foods aimed to differentially regulate immune responses against gastric and intestinal pathogens.