Rifaximin, gut microbes and mucosal inflammation: unraveling a complex relationship

Abstract

Rifaximin is a non-systemic, broad-spectrum antibiotic that acts against gram-positive, gram-negative, and anaerobic bacteria. Clinical studies indicate that rifaximin is beneficial in treating irritable bowel syndrome (IBS). The mechanism responsible for the beneficial effects of rifaximin is not clear. In a recent study, we reported that rifaximin alters the bacterial population in the ileum of rats, leading to a relative abundance of Lactobacillus species. These changes prevent gut inflammation and visceral hyperalgesia caused by chronic stress. To more closely mirror human clinical studies in which rifaximin is used to treat IBS symptoms, we performed additional studies and showed that rifaximin reversed mucosal inflammation and barrier dysfunction evoked by chronic stress. These beneficial effects were accompanied by a striking increase in the abundance of Lactobacillaceae and a marked reduction in the number of segmented filamentous bacteria after rifaximin treatment. These microbial changes may contribute to the antiinflammatory effects of rifaximin on the intestinal mucosa.

Keywords: :

• Lactobacillus
• segmented filamentous bacteria
• tight junction protein
• inflammatory cytokines
• gut microbiota
• irritable bowel syndrome
• psychological stress

This article refers to:

10.4161/gmic.32130

Acknowledgments

Grant support: These studies were supported by the National Institutes of Health grants R01 DK058913 (CO) and P30 DK34933 (CO).