Overgrowth of bacteria in the small intestine may be much more common in people with restless legs syndrome than in the general population, a small pilot study suggests.

Seven participants in the study returned faecal samples revealing small-intestinal bacterial overgrowth (SIBO), a condition thought to occur in between 6% and 15% of the population at large, according to data presented in June at Sleep 2019, the annual meeting of the Associated Professional Sleep Societies in Texas, US.

The researchers collected faecal samples and breath tests from participants in three groups: restless legs syndrome (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 completed the protocol, all reported poor sleep quality and moderate-to-severe symptoms of RLS, and all were found positive for bacterial overgrowth.