In a small study (n = 7), 100% of individuals with restless leg syndrome (RLS) had small intestine bacterial overgrowth (SIBO); the rate of SIBO in the general population is only 6% to 15%. Iron deficiency in the brain is a known risk factor for RLS appearing to change adenosine, glutamate and dopamine pathways. Brain iron deficiency could be secondary to dietary iron deficiency or gut inflammation, which, in turn, could be caused by SIBO. It has also been suggested that RLS is correlated with risk of developing Parkinson’s disease, for which there is also evidence of a role for gut microbes.
“We’ve observed extremely high rates of small intestinal bacterial overgrowth in the RLS group,” said lead author Daniel Jin Blum, PhD, DBSM, an adjunct clinical instructor at Stanford Center for Sleep Sciences and Medicine in Redwood City, California. “Exploring the relationship between RLS and gut microbial health has the potential to open novel avenues for possible detection, prevention and treatment for RLS and other sleep disorders.”
Study participants were all diagnosed with RLS and had poor sleep quality as measured by a score of 5 or more on the Pittsburgh Sleep Quality Index (PSQI) and moderate to severe symptoms as measured by International Restless Legs Scale score of 13 to 34 out of a possible 40. Presence of SIBO was examined through fecal and breath samples.
Recruitment for this study continues and analyses will examine fecal microbial composition, subtypes of RLS iron deficiency, and comparisons with insomnia.
These results are published in the journal Sleep and are being presented at SLEEP 2019, the 33rd annual meeting of the Associated Professional Sleep Societies (APSS) in San Antonio, TX.