Effect of Lactobacillus pentosus ONRIC b0240 on intestinal IgA production in mice fed differing levels of protein.

Protein-energy malnutrition (PEM) is frequently associated with the occurrence of infection due to a decline in immune function. Here, an experiment was conducted with the objective of enhancing mucosal immunity by administration of Lactobacillus pentosus ONRIC b0240 (b240) in PEM model mice. Three groups of male C3H/HeN mice aged approximately 12 weeks were caged in groups of five or six and received various treatments. The mice were fed 4 (low-protein diet; PEM model), 20 (standard-protein diet), or 40% (high-protein diet) ovalbumin (OVA) with or without 0.05% b240. Five weeks later, all mice were sacrificed, and the organs were extracted for analysis of the immune response. Acute toxicity was not observed in this study. The addition of b240 showed no influence on body weight; however, body weight decreased with increasing protein level. Interestingly, intestinal total IgA was significantly increased (p<0.05) in all test diets with b240. The in vitro study showed that the number of B cells and type 2 helper T (Th2) cells were significantly increased in mouse spleen cells with b240 treatment, whereas no differences were found in the number of Th1 cells. b240 also has the ability to augment IgA and IgG production in mouse Peyer's patch cells. These results suggest that b240 enhances IgA production and helps recover the intestinal immune system in PEM model mice via augmentation of humoral immunity.