Probiotics May Reduce Negative Thoughts Associated with Sad Mood

by | Sep 10, 2018 | 2015, Brain Health, Depression, Probiotics

Written by Angeline A. De Leon, Staff Writer. This study suggests that a probiotic combination of different strains and species of Lactobacillus, Lactococcus, and Bifidobacterium can significantly reduce negative thoughts, specifically for aggression and rumination.

depressionThe brain-gut axis is a bidirectional pathway between the central nervous system and the gastrointestinal tract, linking the cognitive center of the brain with peripheral intestinal functions 1. Through this pathway, bacterial products such as endotoxins can influence mood and cognition through immune activating mechanisms 2. Preclinical evidence from studies of anxiety and depression suggest that modification of the microbiome through probiotic supplementation can therapeutically alter stress response and mood 3,4. In animal studies, for example, Lactobacillus rhamnosus JB-1 has been linked to a reduction in anxious and depressive behavior 5that was comparable to the effects of antidepressant administration 6. In an early study with human subjects, researchers also demonstrated improvement in mood after only three weeks of daily ingestion of a probiotic-containing milk product (Lactobacillus casei Shirota) 7. Based on these findings, probiotic supplementation appears to be a promising adjuvant treatment for depression; however, further research is needed to identify the most effective type of multispecies probiotics (best combination of different probiotic strains) for mood support. In a 2015 study, researchers in the Netherlands investigated the possible benefits of probiotics on cognitive reactivity to sad mood (referring to activation of dysfunctional patterns of thinking predictive of depression 8), using a multispecies probiotic containing different strains and species of Lactobacillus, Lactococcus, and Bifidobacterium.

Employing a triple-blind, placebo-controlled, randomized study design, a total of 40 healthy, non-smoking volunteers (mean age = 20 years) without any current mood disorder were randomly allocated to ingest either a multispecies probiotic (28 sachets each containing 2 g of a freeze-dried probiotic mixture consisting of Bifidobacterium bifidum W23, Bifidobacterium lactis W52, Lactobacillus acidophilus W37, Lactobacillus brevis W63, L. casei W56, Lactobacillus salivarius W24, and Lactococcus lactis W19 and W58) or matching placebo consisting of maize starch and maltodextrins daily for four weeks. At pre- and post-intervention, cognitive reactivity to sad mood was assessed using the revised Leiden index of depression sensitivity scale (LEIDS-r).

Data analysis revealed significant time x group interactions for total LEIDS-r score [F(1,38) = 6.05, p = 0.019)], aggression sub-score [F(1,38) = 4.94, p = 0.032)], and rumination sub-score [F(1,38) = 12.16, p = 0.001)], with participants in the probiotic group showing significantly lower scores for total LEIDs-r (42.75 +/- 3.24 vs. 33.35 +/- 3.51, p < 0.001), aggression (8.68 +/- 0.94 vs. 6.25 +/- 0.98, p = 0.004), and rumination (11.20 +/- 0.90 vs. 8.25 +/- 0.93, p < 0.001) from pre- to post-intervention. In contrast, placebo showed comparable scores from beginning to end of intervention.

Findings provide initial evidence to suggest the efficacy of a multispecies probiotic in reducing negative thoughts associated with sad mood, specifically those associated with aggression and rumination. Research should continue to investigate the applicability of probiotic interventions to high-risk clinical populations, such as those suffering from anxiety and other mood disorders, and determine optimal combinations of other probiotic strains.

Source: Steenbergen L, Sellaro R, van Hemert S, et al. A randomized controlled trial to test the effect of multispecies probiotics on cognitive reactivity to sad mood. Brain, Behavior, and Immunity. 2015; 48: 258-264. DOI: 10.1016/j.bbi.2015.04.003.

© 2015 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

 Click here to read the full text study.

Posted September 10, 2018.

Angeline A. De Leon, MA, graduated from the University of Illinois at Urbana-Champaign in 2010, completing a bachelor’s degree in psychology, with a concentration in neuroscience. She received her master’s degree from The Ohio State University in 2013, where she studied clinical neuroscience within an integrative health program. Her specialized area of research involves the complementary use of neuroimaging and neuropsychology-based methodologies to examine how lifestyle factors, such as physical activity and meditation, can influence brain plasticity and enhance overall connectivity.
  

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