Probiotics drive gut microbiome triggering emotional brain signatures

Gut Microbes. 2018 Nov 2;9(6):486-496. doi: 10.1080/19490976.2018.1460015. Epub 2018 Jun 14.


Experimental manipulation of the gut microbiome was found to modify emotional and cognitive behavior, neurotransmitter expression and brain function in rodents, but corresponding human data remain scarce. The present double-blind, placebo-controlled randomised study aimed at investigating the effects of 4 weeks' probiotic administration on behavior, brain function and gut microbial composition in healthy volunteers. Forty-five healthy participants divided equally into three groups (probiotic, placebo and no intervention) underwent functional MRI (emotional decision-making and emotional recognition memory tasks). In addition, stool samples were collected to investigate the gut microbial composition. Probiotic administration for 4 weeks was associated with changes in brain activation patterns in response to emotional memory and emotional decision-making tasks, which were also accompanied by subtle shifts in gut microbiome profile. Microbiome composition mirrored self-reported behavioral measures and memory performance. This is the first study reporting a distinct influence of probiotic administration at behavioral, neural, and microbiome levels at the same time in healthy volunteers. The findings provide a basis for future investigations into the role of the gut microbiota and potential therapeutic application of probiotics.

Keywords: Emotional decision; behavior; fMRI; microbiome; probiotics; recognition, memory; stool.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Bacteria / classification
  • Bacteria / genetics
  • Bacteria / isolation & purification
  • Bacterial Physiological Phenomena*
  • Brain / diagnostic imaging
  • Brain / microbiology
  • Brain / physiology*
  • Decision Making
  • Double-Blind Method
  • Emotions* / physiology
  • Feces / microbiology
  • Female
  • Gastrointestinal Microbiome / physiology*
  • Healthy Volunteers
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Placebos
  • Probiotics*
  • RNA, Ribosomal, 16S / genetics
  • Recognition, Psychology
  • Young Adult


  • Placebos
  • RNA, Ribosomal, 16S

Grants and funding

This study was supported by funding from Institut Allergosan (Graz, Austria) and Winclove (Amsterdam, Netherlands). No funding bias has been associated with this study. Funding parties did have no influence on study design, analysis, or interpretation of results.