AUTHOR=Garcia-Castillo Valeria , Komatsu Ryoya , Clua Patricia , Indo Yuhki , Takagi Michihiro , Salva Susana , Islam Md. Aminul , Alvarez Susana , Takahashi Hideki , Garcia-Cancino Apolinaria , Kitazawa Haruki , Villena Julio 

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

JOURNAL=Frontiers in Immunology

VOLUME=10

YEAR=2019

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2019.01376

DOI=10.3389/fimmu.2019.01376

ISSN=1664-3224

ABSTRACT=<p><italic>Lactobacillus fermentum</italic> 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 <italic>Helicobacter pylori</italic> infection in human gastric epithelial cells. In this work, we conducted further <italic>in vitro</italic> studies in intestinal epithelial cells (IECs) and <italic>in vivo</italic> experiments in mice in order to characterize the potential immunomodulatory effects of <italic>L. fermentum</italic> 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 <italic>L. fermentum</italic> UCO-979C is able to exert its immunomodulatory effect in the intestinal mucosa <italic>in vivo</italic>. The feeding of mice with <italic>L. fermentum</italic> UCO-979C significantly increased the production of intestinal IFN-γ, stimulated intestinal and peritoneal macrophages and increased the number of Peyer's patches CD4<sup>+</sup> T cells. In addition, <italic>L. fermentum</italic> UCO-979C augmented intestinal IL-6, reduced the number of immature B220<sup>+</sup>CD24<sup>high</sup> B cells from Peyer's patches, enhanced the number of mature B B220<sup>+</sup>CD24<sup>low</sup> cells, and significantly increased intestinal IgA content. The results of this work revealed that <italic>L. fermentum</italic> 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.</p>