Antibiotic for the treatment of IBS

Based on the theory that there could be small intestinal bacterial overgrowth (SBO) in IBS patients, antibiotics have been tried as treatment. Antibiotics have helped some IBS sufferers, especially those with complaints of diarrhea, excess bloating and gas, and abdominal pain.

Without well-designed scientific studies demonstrating clear efficacy, antibiotic use has remained somewhat empirical, and the questions remain which antibiotic, for how long, and how often. Furthermore, the role of SBO has been overestimated in the past, with an estimate that only 5-10% of IBS patients have confirmed bacterial overgrowth. However, more recently, the role of post-infectious IBS and altered gut flora in IBS, as well as the availability of non-absorbed antibiotics such as Rifaximin and high-quality probiotics such as VSL#3, has led to increased interest in IBS therapy. antibiotics and probiotics.

Two recent multicenter, randomized, double-blind, placebo-controlled trials, TARGET 1 and TARGET 2, involving more than 1,000 patients given rifaximin or placebo, have shown favorable but not “breakthrough” results. The rifaximin dose was 550 mg 2-3 times daily versus placebo, for two weeks followed by another 10 weeks of follow-up. Constipated IBS patients were excluded. Abdominal distension and a global assessment of IBS symptoms using a standardized scale were the primary endpoints, while abdominal pain and stool frequency were secondary endpoints.

Abdominal pain, bloating, and stool symptoms improved after rifaximin treatment. When data from both studies were combined, it was observed that 41% of those receiving rifaximin versus 32% in the placebo group (30% placebo response rate typical in most treatment studies). Although this achieved statistical significance, it’s not a great response rate, significantly less than 50% response. A statistically significant improvement was observed over the three-month study period.

The limitations of my stand study are that leaky gut markers and IBD serology were not checked and mast cell staining was not performed in these patients. Patients also did not receive probiotics.

One of the main advantages of rifaximin is that it is not absorbed from the gastrointestinal tract, so it does not present systemic side effects. It also tends to be fast if it works and has been documented to last up to three months. The downside is that it’s expensive, often not covered by insurance, and doesn’t work for more than half of those who try it. Adding a probiotic may help, although there are limited studies to support this as a formal recommendation. A theoretical disadvantage is the possible selection of more resistant bacteria in the intestine.

It’s a regimen that may be worth trying if your insurance covers the antibiotic. I would recommend that celiac disease, inflammatory bowel disease (ulcerative colitis and Crohn’s disease), and microscopic colitis (lymphocytic colitis, collagenous colitis, and mast cell enterocolitis) be excluded by blood tests and endoscopies with biopsies.