Lactic Acid Bacteria and their Bioactive Compounds: Key Regulators of Gut Microbiota and Immune Function

The gut microbiota is the complex and dynamic community of bacteria, fungi, parasites, and viruses that enter into a synbiotic relationship with the cells of the host. They protect the host against pathogens, shape and strengthen the intestinal epithelium, and influence the immune system. The bacterial metabolites can enter the host bloodstream and influence other parts of the body through various axes in humans and animals, such as gut-microbiota-brain, gut microbiota-skin, gut-vagina, gut-liver, gut-bones, etc. However, many aspects of modern lifestyle can cause alterations in the gut microbiota and lead to numerous diseases including inflammatory bowel disease, diabetes mellitus, obesity, and metabolic syndrome. Probiotics and other beneficial microbes can exert many beneficial effects on their hosts by modulating the gut microbiota. While the term probiotic is reserved only for well-characterized strains with clinically proven health benefits, other beneficial microbes include those responsible for the fermentation of foods, such as yogurt, kefir, kombucha, kimchi, and many others that have been shown to have various health benefits. Many of these beneficial microbes belong to lactic acid bacteria. Lactic acid bacteria (LAB) are Gram-positive, usually non-motile, catalase-negative, aerotolerant rods or cocci with high tolerance to low pH that produce lactic acid by fermentation of carbohydrates. Lactic acid bacteria have many therapeutic and functional properties that are beneficial to human health.

This research topic aims to compile articles focusing on new insights into the role of lactic acid bacteria in the regulation of the gut microbiota. The main objectives include understanding how LAB influence gut microbiota composition, identifying bioactive compounds produced by LAB and their effects, elucidating the molecular mechanisms underlying LAB's impact on immunity, pathogen exclusion, and intestinal barrier function, and exploring potential therapeutic interventions involving LAB. By addressing these questions, the research aims to fill existing gaps in our knowledge and provide a comprehensive understanding of LAB's multifaceted roles in gut health and beyond.

To gather further insights into the role of lactic acid bacteria in the regulation of gut microbiota, we welcome articles addressing, but not limited to, the following themes:

- Influence of lactic acid bacteria on gut microbiota composition
- Bioactive compounds produced by lactic acid bacteria and their influence on gut microbiota composition
- Molecular mechanisms underlying the effects of lactic acid bacteria and their metabolites on immunity, pathogen exclusion, and intestinal barrier function related to the gut microbiota and beyond
- Potential therapeutic interventions with lactic acid bacteria and their metabolites related to the gut microbiota and beyond