The Role of Antibiotics in Gut Microbiota Modulation: The Eubiotic Effects of Rifaximin

Abstract

Antibiotics are mainly used in clinical practice for their activity against pathogens, but they also alter the composition of commensal gut microbial community. Rifaximin is a non-absorbable antibiotic with additional effects on the gut microbiota about which very little is known. It is still not clear to what extent rifaximin can be able to modulate gut microbiota composition and diversity in different clinical settings. Studies based on culture-dependent techniques revealed that rifaximin treatment promotes the growth of beneficial bacteria, such as Bifidobacteria and Lactobacilli. Accordingly, our metagenomic analysis carried out on patients with different gastrointestinal and liver diseases highlighted a significant increase in Lactobacilli after rifaximin treatment, persisting in the short time period. This result was independent of the disease background and was not accompanied by a significant alteration of the overall gut microbial ecology. This suggests that rifaximin can exert important eubiotic effects independently of the original disease, producing a favorable gut microbiota perturbation without changing its overall composition and diversity.

Eubiotic properties of rifaximin: Disruption of the traditional concepts in gut microbiota modulation

“…In the second study[81], rifaximin was administered at the dose of 1200 mg daily for 10 d to patients with different gastrointestinal diseases, including irritable bowel syndrome, CD, ulcerative colitis and diverticular disease, and also to patients with liver cirrhosis complicated by hepatic encephalopathy. Stool samples were analyzed before, at the end and 1 mo after the end of rifaximin treatment.…”

“…Data from metagenomic studies reflect this characteristic. Indeed, immediately after the beginning of rifaximin treatment, bacterial alpha diversity shows a trend towards reduction, reverting to values similar to pre-treatment after a wash-out period[80,81]. …”

Impact of Early-Life Antibiotic Use on Gut Microbiota of Infants

“…In recent years, experimental studies showed that antibiotics can destroy the structure of normal gut microbiota and change the functions [16,17]. In the study of Klemm and Dougan, they have found that antibiotics use led to remarkable changes in the structure of gut microbiota by phylogenetics analysis [18].…”

A Review of Experimental and Off-Label Therapies for Clostridium difficile Infection

“…It is considered to have very little and rather beneficial effect on the normal intestinal microbiota [6, 7], though its complete innocuousness in patients receiving long-term rifaximin treatment is questionable [8]. It was equally efficient as vancomycin in a hamster model of CDI, and—depending on the C. difficile strain used—similar or lower recurrence rates were observed after rifaximin withdrawal as compared to the vancomycin group [9].…”