The Role of Probiotics Limosilactobacillus reuteri, Ligilactobacillus salivarius, and Lactobacillus johnsonii in Inhibziting Pathogens, Maintaining Gut Health, and Improving Disease Outcomes

As the critical component of the gastrointestinal tract, which lives in trillions of gut microorganisms, in a healthy state, the host interacts with the gut microbiota and is symbiotic. The species <i>Limosilactobacillus reuteri</i>, <i>Ligilactobacillus salivarius</i>, and <i>Lactobacillus johnsonii</i> are indigenous gut commensal bacteria that are mainly found in the digestive tracts. These three bacteria possess a variety of characteristics that reflect their ability to adapt to the gastrointestinal environment. Herein, we summarize the current progress of research on the probiotic properties of these strains in terms of their ability to protect against harmful pathogens, maintain intestinal health, and improve disease outcomes. These bacteria can impact the intestinal barrier function and enhance intestinal immunity through various mechanisms, such as upregulating the tight-junction protein expression and mucin secretion of intestinal epithelial cells, adjusting and balancing the gut microbiota, and blocking pro-inflammatory cytokine production. They have been shown to ameliorate intestinal inflammation in animal models and provide protective effects against various healthy issues in humans, including diarrhea, constipation, colorectal cancer, obesity, and liver diseases. However, the detailed mechanisms of certain strains remain unclear.