An Overview on the Function of Probiotics and Their Positive Effects on Enhancing Intestinal Immune Responses

Probiotics are alive and beneficial microorganisms that affect the body’s microbial flora when consumed by humans or animals and have beneficial effects on the health of the host. Nowadays, probiotics are considered a factor in the prevention of many infectious diseases and cancers. Given the particular importance of probiotics, this study aimed to narratively review previous studies on the mode of action of probiotics and the beneficial effects of probiotics on enhancing intestinal immune responses. Articles on this topic were searched in Google Scholar, Springer, Science Direct, and Clinical Trial databases, and systematic review articles examining the effects of probiotics on the function of the intestinal immune response were included in the study. The results of the research showed that probiotics can boost the body’s immune system, break down food due to their ability to produce enzymes, lower the pH of the environment, and secrete bacteriocins. Furthermore, the effect of probiotics on the modulation mechanisms of the innate defense responses of the intestinal epithelium, including the stimulation of trefoil factor 3, induction of antimicrobial peptide (AMP) secretion, stimulation of secretory immunoglobulin production, and stimulation of toll-like receptors increase in heat shock protein production, modulation of P-glycoprotein (P-gp) and regulation of mucins by probiotics. Therefore, probiotics are expected to be used as an adjunct treatment for many digestive and infectious diseases.