DDW: IBS And Restless Legs Syndrome Linked

WASHINGTON, May 24 -- Bacterial overgrowth in the gut, a factor in irritable bowel syndrome, may also be at work in restless legs syndrome and antibiotics can help both conditions, one small study suggests.

In 13 patients suffering from both conditions, all saw improvement in IBS symptoms and 10 found marked relief from restless legs symptoms after a 10-day course of antibiotics, said Leonard Weinstock, M.D., of Washington University in St. Louis.

Dr. Weinstock hypothesized a connection between IBS and restless legs syndrome when his cousin came down with both conditions after contracting a case of travelers' diarrhea, Dr. Weinstock told attendees at Digestive Disease Week here.

He said he'd also heard reports of IBS being linked with fibromyalgia, which in turn has been linked with restless legs syndrome. He hypothesized that bacterial overgrowth in the gut could be causing the problems and that antibiotic therapy targeting the small intestine might be the solution.

He tested his idea in a pilot study during which participants received a 10-day course of rifaximin (1,200 mg/day), which specifically destroys bacterial overgrowth in the small intestine. This short-term antibiotic therapy was followed by long-term tegaserod, and a one-month course of zinc and probiotic therapy, Dr. Weinstock said. The patients were followed for an average of 107 days.

Results became apparent, however, by day 11, he said. Abdominal pain improved by 74%, diarrhea by 73%, bloating by 70%, constipation by 64%, and flatulence by 47% from baseline. These improvements were maintained long-term, the study found.

Overall, IBS symptoms were rated as greatly improved by six patients, moderately improved by five, and mildly improved by two.

Restless legs syndrome symptoms improved as well: 10 of the 13 patients experienced an 80% improvement or greater from baseline after the antibiotic treatment. Five of them achieved and maintained 100% improvement in symptoms, Dr. Weinstock said.

Previous studies have shown that bacterial overgrowth in the small intestine causes inflammatory cells to increase production of IL-6, he noted. This cytokine, in turn, is known to boost levels of hepcidin, a protein that decreases iron absorption and transport. Because iron deficiency has been linked with restless legs syndrome, this process could account for the apparent link between IBS and restless legs, Dr. Weinstock speculated.

"Comprehensive bacterial overgrowth therapy may provide long-term improvement in symptoms of both IBS and restless legs syndrome, and further research on extra-gastrointestinal manifestations of bacterial overgrowth are warranted," Dr. Weinstock said.

"Our study provides the basis for a potential curative treatment for some patients, whereas current therapies only partially alleviate symptoms," he noted.

Dr. Weinstock and colleagues are undertaking a multi-center study with more than 600 patients to see if the pilot study results hold up.