Gut bacteria may play a role in restless-legs syndrome

Last Updated: 2019-06-18

By Rob Goodier

NEW YORK (Reuters Health) - Overgrowth of bacteria in the small intestine appears to be much more common in people with restless-legs syndrome (RLS) than in the general population, a small pilot study suggests.

All seven participants studied returned fecal samples revealing small-intestinal bacterial over-growth (SIBO), a condition thought to occur in between 6% and 15% of the population at large, according to data presented June 9 at Sleep 2019, the annual meeting of the Associated Professional Sleep Societies in San Antonio, Texas.

A growing body of research suggests possible connections between gut health and sleep, lead author Dr. Daniel Blum of the Stanford Center for Sleep Sciences and Medicine told Reuters Health by email.

"Within that, gut-microbiota and iron-absorption issues in RLS seemed like a very interesting and relatively new avenue to explore," Dr. Blum said.

The researchers are collecting fecal samples and SIBO breath-test from participants in three groups: RLS with low peripheral iron stores, RLS with normal iron stores, and patients with insomnia as a control group.

Among the seven RLS patients (three men, four women) who had completed the protocol when the researchers analyzed their data, all reported poor sleep quality and moderate to severe symptoms of RLS and all were found positive for SIBO.

Notably, unpublished data show higher-than-normal SIBO rates in the insomnia group as well, Dr. Blum said.

"We are definitely surprised at the high rates of SIBO and will be interested to see if the fecal sequencing will provide additional insights," he said.

If borne out in larger studies, the results suggest that treatments targeting gut dysbiosis might also be effective against RLS. This pilot study, however, is too small to make recommendations at this point, said Dr. Raman Malhotra, an associate professor of neurology at Washington University Schools of Medicine in St. Louis, Missouri, who was not involved in the research.

"I do believe this should be further evaluated with more patients, and making sure that there is a good demographic mix reflective of the general population," he told Reuters Health by email. "Genetics and family history play a role in restless-legs syndrome and not all patients with restless-legs syndrome have iron deficiency. Therefore, it will be important to identify different groups of RLS patients to see if there is a difference, as my guess is that the effect of gut microbes on RLS may be important for some but not all patients."

Dr. Blum and colleagues do not have further research planned, but they are interested in follow-up studies of larger samples, as well as the potential effects of treating gut health, Dr. Blum said.

SOURCE: https://bit.ly/2XScWuF

Sleep 2019.