Evaluation of the immunomodulatory ability of proteolitic Lactobacillus strains and their derivatives β-casein hydrolysates

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

Conferencia; 2019 Annual Meeting of the Japan Association of Food Immunology; 2019

Probiotics and their bioactive peptides can contribute to prevent or reduce the intestinal tissuedamage during infections through the beneficial modulation of the innate immune response. Inthis work, the immunomodulatory effect of Lactobacillus rhamnosus A29 (Lr29), Lactobacillusdelbrueckii spp. lactis CRL581 (Ld581), Lactobacillus delbrueckii spp. bulgaricus CRL656(Ld656), and their respective hydrolysates of β-casein (βhy29, βhy581 and βhy656) wereevaluated in a murine model. Different groups of 5-weeks-old Balb/c mice were fed with Lr29,Ld581 or Ld656 (10 8 cells/mouse/day) or βhy29, βhy581 or βhy656 (300 ug/mouse/day) during3 consecutive days. One day after the last lactobacilli or β-casein hydrolysates treatments, micewere challenged with the TLR3 agonist poly(I:C) by intraperitoneal injection. Before and afterpoly(I:C) challenge the following parameters were evaluated: phagocytic and microbicidal(NBT) activity of peritoneal macrophages, intestinal IgA, IL-10 and IFN-γ levels, andhistological analysis of intestine. Treatment of mice with Ld581 significantly increased thepercentage of phagocytosis and NBT + cells among peritoneal macrophages as well as the levelsof intestinal IL-10 and IFN-γ when compared to untreated controls. Slight increases ofperitoneal macrophages phagocytic activity and intestinal IL-10 and IFN-γ levels were observedin Lr29-treated mice. No significant changes were observed in the evaluated parameters for thegroups receiving Ld656, βhy29, βhy581 or βhy656 when compared to control mice. As reportedpreviously, intraperitoneal injection of poly(I:C) induced intestinal inflammation and tissuedamage in control animals. However, Ld581-treated mice showed significantly lower intestinaltissue damage than controls. In addition, Ld581 was able to significantly improve the levels ofboth 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 immunologicalparameters when compared to controls. The results of this work show that the technologicallyrelevant and high proteolitic strain L. delbrueckii spp. lactis CRL581 is able to beneficiallymodulate intestinal innate antiviral immune response. Although further studies with theCRL581 strain are required to corroborate and deepen its immunological effects, this bacteriumis an interesting alternative for the development of new functional foods with antiviralcapabilities.