Across 3 review articles, all reported beneficial but small-sized effects of Bifidobacterium bifidum Rosell-71 on mental health outcomes. No consistent dose, form, or duration data were reported, and no study reported statistically significant results. The evidence is derived entirely from secondary analyses, not direct trials.
Caveats: Evidence base is small (only 3 studies) and consists entirely of review articles, not primary clinical trials. Available evidence is overwhelmingly positive, but publication bias is likely (null-result studies are less likely to be published or indexed). None of the included reviews reported statistically significant findings from the underlying studies, suggesting the true effect may be smaller than the observed direction implies. No dose, form, or duration data were consistently reported, limiting actionable conclusions.
it appears that probiotics have a beneficial effect on mental health, cognitive functions, sleep, gastrointestinal, and upper respiratory symptoms in adult humans.
Ten studies investigated the same combination of probiotics and provided evidence to support the claims made. Statistically significant results were not universally present for all products.
Psychobiotics are probiotics that contribute beneficially to the brain function and the host mental health... the potential therapeutic effects of the psychobiotics alone or in combination with conventional medicine in the treatment of... some psychiatric diseases like depression, schizophrenia, and bipolar disorder