A new meta-analysis suggests that taking probiotics may lead to small improvements in sleep quality. The review combined data from 39 randomized trials involving over 4,000 adults and adolescents. Participants who took probiotics had slightly better scores on the Pittsburgh Sleep Quality Index (PSQI), a common measure of sleep health, compared to those who took a placebo.
The analysis found that probiotics helped reduce daytime dysfunction and slightly increased total sleep time by about 14 minutes on average. Some measures of insomnia severity improved only after removing certain studies, and the overall certainty of the evidence was rated as very low to low. This means the findings should be interpreted with caution.
While the results are promising, the improvements were modest. For example, the global PSQI score improved by less than one point on a scale of 0 to 21. The authors note that it is unclear whether such small changes are meaningful for people with sleep problems. More research is needed to confirm the benefits and understand which probiotics work best.