Researchers say supplements may have cognitive benefits, call for more studies
Written by Marisa Wexler, MS | May 1, 2026
- Probiotics did not reduce anxiety in Parkinson's patients more than a placebo.
- However, probiotic use showed potential cognitive improvements.
- Further research is needed to confirm probiotics' cognitive benefits in Parkinson's.
A small clinical trial testing whether a probiotic supplement could ease anxiety in people with Parkinson’s disease found that it was no better than a placebo.
However, patients given the supplement showed significant improvements on cognitive tests compared with those given the placebo. The researchers cautioned that this finding should be interpreted cautiously, and called for further studies to explore whether probiotics may help improve cognition in Parkinson’s.
“While no group differences were observed for neuropsychiatric symptoms following the 12-week intervention, the potential cognitive benefits seen in the probiotic group warrant further investigation,” they wrote in the study, “Probiotic supplementation for anxiety symptoms in people with Parkinson’s disease: a randomized, double-blind, placebo-controlled trial,” which was published in npj Parkinson’s Disease.
Anxiety — uncontrollable worry or fear — is a common nonmotor symptom of Parkinson’s that can cause substantial distress. Although talk therapy and medication may help manage anxiety, these available therapies don’t work for everyone. Researchers are actively searching for new ways to help ease anxiety.
Probiotics are a broad class of supplements containing living bacteria that are thought to be beneficial for health. More than 20 clinical trials have tested whether various probiotic supplements can ease anxiety in the general population, with some reporting promising effects. A few studies have also tested whether probiotics can help ease various symptoms of Parkinson’s, but there’s minimal data on whether probiotics may help ease anxiety in people with this neurological disease.
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