ROLE OF PROBIOTIC BACTERIA IN IMMUNITY AND INFLAMMATION

PERDIGON G; MALDONADO GALDEANO C; CAZORLA SI

Congreso; Reunión Anual de Sociedades de Biociencias 2020; 2020

Scientific advances in the signals induced for the microbiota allowed to understand how the probiotics influence the mucosal immune system (MIS). Probiotics induce a network of signals to the gut immune cells to activate the MIS. These bacteria interact with the intestinal immune cells (IECs) inducing Goblet and Paneth cells to produce mucus and antimicrobial peptides (AMPs). The interaction between IECs and probiotics is mediated by cytokines release without eliciting inflammatory mechanisms in the host, in contrast with pathogens. How probiotics achieve a balance between stimulation and anti-inflammatory mechanisms? Probiotic strains stimulate the MIS increasing IgA+ cells in the intestine, bronchus and breast and induce immunomodulation through IL-10. We also demonstrated that probiotics stimulate innate immune cells: dendritic cells and macrophages without tissue damage. Probiotics induce an activation of proteins regulatory genes that modulate the NFkB and MAPK via. These genes are not activated by pathogens. The biological mechanisms observed open the door for the study of anti-inflammatory mechanisms, from probiotic, probiotic fermented milk (PFM) and Yogurt. In an acute inflammatory model induced by Salmonella, probiotics lactobacilli oral administration was able to reduce the inflammation through the production of AMPs that minimize the internalization of the pathogen to the intestine. In a respiratory allergy model the PFM induced a balance to Th1 with production of IgG instead of IgE. These previous results led us to study the anti-inflammatory mechanisms mediated by yogurt in a model of ulcerative colitis. We demonstrated that the main effect of yogurt is the decrease of IL-17 and the increase of IL-10. In a model of chronic inflammation as obesity we observed a diminution in markers of metabolic syndrome. Probiotics, PFM and yogurt have an important role in the mechanisms of the immune surveillance, playing a role in the immunoregulation of the MIS.