Can fecal microbe transplantation improve sleep in people with chronic insomnia?

In a randomized clinical trial published in the Journal of Internal Medicine, ingesting capsules containing fecal microbes from healthy donors helped treat symptoms of insomnia.

One month after treatment, participants receiving fecal microbiota capsules showed significantly higher sleep efficiency and reduced wake after sleep onset, as measured by overnight polysomnography. Patient questionnaires also showed that sleep quality scores improved from 2 to 6 months in the intervention group compared with the placebo group.

"Our findings provide clinical evidence that targeting the gut microbiota may offer a promising new therapeutic strategy for chronic insomnia disorder,” said co–corresponding author Yanping Bao, PhD, of Peking University, in Beijing. “This work also strengthens our understanding of the gut–brain axis as an important regulator of human sleep.”

Reference:

Gao T, Liu X, Mi W, Shi L, Wang X, Zhu D, et al. Fecal microbiota transplantation-based treatment protocol for chronic insomnia disorder: A randomized, double-blind, placebo-controlled trial. J Intern Med. 2026; 1–19.