Oral probiotics supplementation can stimulate the immune system in a stress process

In a bifactorial stress mouse model we studied the effect of probiotic supplementation on biochemical parameter in serum, the intestinal impairment of the villi induced by stress, the systemic immune response and the susceptibility to intestinal infections. Probiotic effect was also evaluated on cells from the innate immunity. Mice were subjected to a stress protocol based on food deprivation and movement restrictions for 11 days. We analyzed the probiotic supplementation effect, as probiotic bacteria suspension or as a fermented milk, on the changes induced by stress: biochemical parameters as glucose, triglycerides and cholesterol in serum, body weight and in the gut we determined the number of goblet cells, the length of the microvilli and bacterial translocation from the intestinal microbiota into deep tissues. Peritoneal and spleen macrophages activity, the immune response to ovalbumin immunization, the protection against Salmonella infection during the stress process in mice receiving probiotic, were also determined. We found that probiotic supplementation in the chronic stress model, improves the gut histological structure, increases phagocytic activity of peritoneal and spleen macrophages, enhance the humoral response to the OVA antigen and protect against Salmonella infection. Conclusion: Probiotic supplementation was able to act on the gut and systemic immunity by improvement of the length and cellularity of the villi, increasing the systemic immune response and protecting against Salmonella infection. The effectiveness on the immune system exerted by probiotic consumption suggests the use of these bacteria as an alternative to minimize the damage induced during stress situation.