Supplementation with a multi-strain probiotic supplement marketed as Bifizen by Probiotical resulted in significant improvements in self-reported mood parameters, as well as de novo synthesis of serotonin, compared to placebo.
 
The study, “Multi-strain Probiotic Supplementation Increases Sleep Quality, Mood, and Neurotransmitter Levels,” was co-authored by Ralf Jäger, PhD, FISSN, CISSN, MBA of Increnovo LLC and senior scientific advisor to Probiotical/Ashland. The study is still in the process of publication.
 
The double-blind, placebo-controlled, randomized study included 70 healthy adults who consumed either a placebo or the supplement daily, the latter of which contained one billion live cells each of L. fermentum LF16, L. rhamnosus LR06, L. plantarum LP01, and B. longum 04.
 
The study duration was six weeks, and biological and self-reporting measurements were taken before the study commenced, at two, four, and six weeks, and after a three-week washout period.
 
Compared to placebo, the supplement group saw significant improvements in all self-reporting mood tests, which included the Leiden Index of Depression Sensitivity Revised, State-Trait Anxiety Inventory, and Revised Life Orientation Test.
 
When it came to sleep quality and duration, the supplement group saw greater sleep quality and duration based on Fitbit tracking and the Pittsburgh Sleep Quality Index.
 
In order to establish that the probiotic had a mechanism of action related to the gut-brain axis, or the interaction between microbial activity in the gut and changes in the brain, the researchers tracked measurements of serotonin, which contributes to sleep and mood. The probiotic significantly increased serotonin levels with no effect on dopamine or cortisol, according to the results.
 
The new study validates previous research which suggested that supplementation with the four probiotic strains found in Bifizen resulted in significant improvements in self-reported measures of sleep quality, mood, anger, fatigue, and depressive feelings. Probiotical notes that reviews have already concluded that probiotic supplementation may lead to better mood, reduced stress and anxiety, and improved cognitive activity.