EVALUATION OF THE IMMUNOMODULATORY ABILITY OF PROTEOLITIC Lactobacillus STRAINS AND THEIR DERIVATIVES BETA-CASEIN HYDROLYSATES

SAAVEDRA, LUCILA; SUDA, YOSHIHITO; ELEAN, MARIANO; OHGI, RYUSUKE; VILLENA, JULIO; HEBERT, ELVIRA M.; AMINUL ISLAM, MD; KITAZAWA, HARUKI

Tokyo

Conferencia; 15th Anniversary Academic Conference (JAFI2019); 2019

Japanese Association for Food Immunology

Probiotics and their bioactive peptides can contribute to prevent or reduce the intestinal tissue damage during infections through the beneficial modulation of the innate immune response. In this work, the immunomodulatory effect of Lactobacillus rhamnosus A29 (Lr29), Lactobacillus delbrueckii spp. lactis CRL581 (Ld581), Lactobacillus delbrueckii spp. bulgaricus CRL656 (Ld656), and their respective hydrolysates of β-casein (βhy29, βhy581 and βhy656) were evaluated in a murine model. Different groups of 5-weeks-old Balb/c mice were fed with Lr29, Ld581 or Ld656 (108 cells/mouse/day) or βhy29, βhy581 or βhy656 (300 ug/mouse/day) during 3 consecutive days. One day after the last lactobacilli or β-casein hydrolysates treatments, mice were challenged with the TLR3 agonist poly(I:C) by intraperitoneal injection. Before and after poly(I:C) challenge the following parameters were evaluated: phagocytic and microbicidal (NBT) activity of peritoneal macrophages, intestinal IgA, IL-10 and IFN-γ levels, and histological analysis of intestine. Treatment of mice with Ld581 significantly increased the percentage of phagocytosis and NBT+ cells among peritoneal macrophages as well as the levels of intestinal IL-10 and IFN-γ when compared to untreated controls. Slight increases of peritoneal macrophages phagocytic activity and intestinal IL-10 and IFN-γ levels were observed in Lr29-treated mice. No significant changes were observed in the evaluated parameters for the groups receiving Ld656, βhy29, βhy581 or βhy656 when compared to control mice. As reported previously, intraperitoneal injection of poly(I:C) induced intestinal inflammation and tissue damage in control animals. However, Ld581-treated mice showed significantly lower intestinal tissue damage than controls. In addition, Ld581 was able to significantly improve the levels of both IL-10 and IFN-γ in the intestine after TLR3 stimulation. Lr29, Ld656 and the three β-casein hydrolysates were not able to reduce intestinal damage or to modulate the immunological parameters when compared to controls. The results of this work show that the technologically relevant and high proteolitic strain L. delbrueckii spp. lactis CRL581 is able to beneficially modulate intestinal innate antiviral immune response. Although further studies with the CRL581 strain are required to corroborate and deepen its immunological effects, this bacterium is an interesting alternative for the development of new functional foods with antiviral capabilities.