Findings on mood support

The double-blind, placebo-controlled, randomized study was co-authored and conducted by Ralf Jäger, Ph.D., FISSN, CISSN, MBA of INCRENOVO LLC, and senior scientific advisor to Probiotical/Ashland. Seventy healthy adults consumed either a multi-strain probiotic (Bifizen, containing 1 billion live cells each of L. fermentum LF16 (DSM 26956), L. rhamnosus LR06 (DSM 21981), L. plantarum LP01 (LMG P-21021), and B. longum 04 (DSM 23233), or placebo. The study duration was 6 weeks; measurements were before the study commenced, and at 2, 4, and 6 weeks, plus 3 weeks of washout.

Mood was measured through several self-reporting instruments: the Leiden Index of Depression Sensitivity Revised (LEIDS-R), State-Trait Anxiety Inventory (STAI), and Revised Life Orientation Test (LOT-R), according to the release. Probiotic supplementation was shown to significantly improve mood in all tests compared to control.

Findings on sleep quality and duration

 Utilizing the self-reported Pittsburgh Sleep Quality Index (PSQI) and Fitbit tracking, those in the probiotic group experienced greater sleep quality and sleep duration than those in the placebo group.

Gut-brain-axis activity was also monitored.

The goal was to determine neurotransmitter impacts of supplementation with the multi-strain probiotic. The finding: Bifizen supplementation significantly increased serotonin levels. There was no effect on dopamine or cortisol.

According to the release, these latest findings validate earlier research showing probiotic supplementation improves sleep quality, mood, anger, fatigue, and depressive feelings. It also supports findings from a review of studies linking probiotic consumption to better mood, reduced stress/anxiety, and improved cognitive acuity.