Immunomodulation of gastrointestinal tract by probiotics: an insight into the role of Lactobacillus sp. and Bacillus sp. on immunity

Abstract

The gastrointestinal tract (GIT) is an immunologically active ecosystem with a crucial role in activating or stimulating the immune system as well as a barrier against microbial antigens. About a hundred trillion microorganisms such as bacteria, viruses, fungi, and protozoa cohabit with the GIT. Gut microbes play a vital role in health and disease, leading to the emergence of ‘probiotics’ a novel therapeutic consumption of live, beneficial cultures. Probiotics exhibit an extensive mechanism of action which include destroying/blocking pathogens, production of antimicrobial compounds, and modulation of the immune system without affecting intestinal homeostasis. Although Lactobacillus sp. is most abundantly used as a probiotic, reports also show the emergence of Bacillus sp. in boosting the immune system and promoting good health. This review attempts to highlight the potential of Lactobacillus and Bacillus species as a probiotic in stimulating the immune system.