A clinical trial from Peking University has found that faecal microbiota transplantation (FMT) from healthy sleepers may help treat chronic insomnia. The study, published in the Journal of Internal Medicine, involved 80 participants who were randomly assigned to receive either FMT capsules with antibiotic pretreatment or a placebo. Results showed that the FMT group experienced improved sleep efficiency and reduced wakefulness after sleep onset, with benefits sustained from two to six months. The treatment was well tolerated, with only mild, self-limited side effects and no serious adverse events.