Probiotics and the Microbiota-Gut-Brain Axis: Focus on Psychiatry

Abstract

Purpose of Review Probiotics are living bacteria, which when ingested in adequate amounts, confer health benefits. Gut microbes are suggested to play a role in many psychiatric disorders and could be a potential therapeutic target. Between the gut and the brain, there is a bi-directional communication pathway called the microbiota-gut-brain axis. The purpose of this review is to examine data from recent interventional studies focusing on probiotics and the gut-brain axis for the treatment of depression, anxiety and schizophrenia. Recent Findings Probiotics are likely to improve depression but not schizophrenia. Regarding anxiety, there is only one trial which showed an effect of a multispecies probiotic. However, determinants like the duration of treatment, dosage and interactions have not been thoroughly investigated and deserve more scientific attention. Summary Microbiome-based therapies such as probiotics could be cautiously recommended for depression to enhance beneficial bacteria in the gut and to improve mood through the gut-brain axis.

PROVIT: Supplementary Probiotic Treatment and Vitamin B7 in Depression—A Randomized Controlled Trial

“…In a recent meta-analysis, 19 double-blind, randomized, placebo-controlled trials on the effect of probiotics on depressive symptoms were published between 2010 and 2019 [17,18]. Notably, only three of them included individuals with major depressive disorder (MDD) [19][20][21], while the other studies were conducted with healthy controls or other clinical populations (e.g., irritable, bowel syndrome, diabetes with coronary heart disease, fibromyalgia) [6,13,15,17,18]. Akkasheh et al [19] included 40 patients with MDD (age 20-55 years) receiving an eight-week intervention with Lactobacillus (L.) acidophilus, L. casei and Bifidobacterium (B.)…”

“…Improvements in depressive symptoms were significantly higher in individuals with MDD treated with probiotics than in those receiving placebo in patients (for a review see [18]). In another review [22], one more study has been identified including an intervention with probiotics compared to placebo in 60 individuals with depression [23].…”

Safety and efficacy of Melissa officinalis extract containing rosmarinic acid in the prevention of Alzheimer’s disease progression

“…In addition, we recently reported RA-triggered monoamine increase in the brain, and inhibition of Aβ aggregation by monoamines in mice fed with RA 9 ; however, RA concentrations in the brain of these mice 8 , 9 were undetectable. Another possibility is that RA might act on peripheral targets such as gastrointestinal tract, which might contribute to prevention of the worsening of neuropsychiatric symptoms 27 .…”

Anxiolytic effects of a galacto-oligosaccharides prebiotic in healthy females (18–25 years) with corresponding changes in gut bacterial composition

“…To date, studies in humans have focused on characterising microbe populations in both health and disease 4 , 13 . In adults the gut microbiota has been related to atypical social functioning in autism 14 and symptoms of anxiety and depression 7 , 15 , 16 . Animal research has suggested that the gut microbiota plays an important role during key moments in the host development, in particular during adolescence, which represents a critical time window where gut microbiota help fine-tune the gut–brain axis 2 , 8 , 17 , 18 .…”