Across 3 studies (all reviews from 2022–2025), all reported small beneficial effects of Lactobacillus helveticus Rosell-52 on mental health outcomes. However, none of the included studies provided statistical significance testing for this specific supplement-outcome pair, and no consistent dose, form, or duration data were extractable. The evidence base is very small and entirely review-level, making the aggregate finding preliminary.
Caveats: Evidence base is small (only 3 studies) — conclusions should be considered preliminary. All three studies are narrative reviews rather than primary clinical trials; no original data specific to Lactobacillus helveticus Rosell-52 for mental health were directly reported. Statistically significant results were not consistently present across the underlying studies reviewed. Available evidence is overwhelmingly positive in direction — clinical literature in this area is subject to publication bias (null-result studies are less likely to be published or indexed).
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.
The highest therapeutic potential is seen in the rational diet, physical activity, use of psychobiotics, and consumption of antioxidants. Research also shows that there are nutritional interventions that have psychoprotective potential.