Probiotical, manufacturer of probiotics and postbiotics, has announced the publication of a US university-based follow-up clinical trial with its multi-strain probiotic, Bifizen, published in the journal, Frontiers in Nutrition.
The placebo-controlled study with 70 healthy women and men revealed a significant effect of the four-strain probiotic on measures of minor depression, anxiety, and mood. The study was led by Chad Kerksick, PhD, of Lindenwood University.
Healthy people endure daily stressors that can impact mood, creating “subsyndromal” states of mild, minor depression and anxiety. Numerous studies during the initial year of COVID-19 revealed an increase in anxiety and depression, in up to one-third of the population.
This randomised controlled trial, which is an expansion of earlier studies with Bifizen, was initiated just before the global pandemic was declared, and then restarted in September, 2020.
Our findings offer an enticing suggestion that Bifizen could have effects in persons living with sub-clinical depression and anxiety
- Chad Kerksick, PhD, of Lindenwood University and study leader
Kerksick said: “We encountered significant challenges in the performance of this trial and appreciate the commitment of the subjects who completed the study. What remains intriguing is the influence of a global pandemic on the psychosocial and mental health of our otherwise healthy subjects. Our findings offer an enticing suggestion that Bifizen could have effects in persons living with sub-clinical depression and anxiety, but this would need to be borne out in systematic clinical trials in appropriate populations.”
Improved mood markers
Researchers had 70 women and men complete the entire nine-week protocol: six weeks of supplementation with Bifizen or a matched placebo, followed by a three-week “washout” period, incorporated to assist the persistence of any observed effects. Research validated questionnaires were used to assess the efficacy of drugs, counseling and dietary supplements.
Among the 35 subjects in the Bifizen group, significant improvements in scores were noted for measures of depression, anxiety, and cognitive reactivity to a sad mood (depression response). These improvements were noted at four and six weeks of supplementation and endured for three weeks after cessation of supplementation. No changes were noted in the placebo group. Additionally, when compared directly with placebo, the anxiety and mood response scores were significantly superior in the Bifizen group.
A potential gut metabolic marker
The intestinal tract is a major site of production of the neurotransmitter serotonin, a metabolite of the amino acid, L-tryptophan. Blood concentrations of serotonin were significantly higher after six weeks of Bifizen supplementation and remained higher after three weeks post-Bifizen.
“We contemplated that although serotonin may be produced in the gut and enter the blood, it cannot be transported into the brain. Circulating serotonin increases may be a surrogate signal of other metabolites being produced in the gut, or influence neural signals from the gut to the brain, and mediate the positive changes in mood that we observed,” added Kerksick. “We are finishing a different manuscript from this study, which characterizes the effects of Bifizen on sleep dynamics. Our data, combined with other data, point towards a biologically real and measurable impact.”
Continued exploration
The gut-brain axis is experienced continually, from butterflies to nausea, after a myriad of emotional encounters and events. The untangling of this complex nerve-host-microbial network remains exciting and challenging. “We are inspired by these findings from Dr Kerksick and his colleagues. Our 2019 study yielded promising results; this follow-up study extends the findings and includes the additional overlay of COVID-19. We are invigorated by these results and will continue to pursue the interface of the gut-brain axis and rationally designed probiotic formulations,” added Probiotical SpA CEO Vera Mogna.
