Probiotics, Brain Structure and Psychological Variables

Summary

Theory and research on the gut-brain-axis emphasize complex interactions between the gut microbiota, immunological and hormonal responses, brain function, brain structure, as well as resulting behavioral manifestations, such as cognitive functions and mental illness. Probiotics are living micro-organisms that change the composition of the gut microbiota and hypothetically have a positive effect on the host's general health and well-being. Probiotic bacteria naturally occur in foods such as Sauerkraut, olives, and dark chocolate, and are currently also added to industrial products such as yogurt.

Regarding the effect of probiotics on brain structure and function, animal studies have shown that the administration of probiotics in mice and rats was linked to neurogenesis in the hippocampus and an improvement of associated cognitive functions. The majority of these studies applied probiotics for 4 weeks. The substances used in these studies were often composed of several bacterial strains, suggesting that the neurogenic effect may not be reducible to a specific type of probiotic bacteria.

Probiotics seem to be effective in improving memory abilities, including spatial and non-spatial memory, both in rodents and humans. Moreover, specifically regarding the beneficial effect of probiotics on anxiety, depression and stress, preliminary evidence in humans is compelling. However methodologically sound (randomized-controlled trial \[RCT\], 'blind') studies are still lacking.

To sum up, the present study is going to be the first RCT with human participants that investigates structural and functional changes of the hippocampus through probiotic bacteria, using Magnet Resonance Imaging (MRI). In addition, the study aims at advancing research in the field by investigating the effects of probiotics on a broad spectrum of cognitive functions, particularly those associated with hippocampal activity (e.g. spatial memory, verbal memory). Furthermore, effects on several types of mental illness (e.g. anxiety, depression, stress) will be studied. Potential translatory mechanisms that may promote the aforementioned effects will be examined, i.e. changes in immunological parameters, 'brain derived neurotrophic factor' (BDNF), and oxytocin.

Conditions

• Depressive Symptoms
• Anxiety
• Stress

Interventions

DIETARY_SUPPLEMENT

Vivomixx® powder

Participants will take in a daily dose of 4.4g for 28 consecutive days

OTHER

Placebo powder

Participants will take in a daily dose of 4.4g for 28 consecutive days

Sponsors & Collaborators

• Universitätsklinikum Hamburg-Eppendorf

  lead OTHER

Principal Investigators

• Simone Kühn, Prof. Dr. · Universitätsklinikum Hamburg-Eppendorf, Klinik und Poliklinik für Psychiatrie und Psychotherapie, UKE Martinistraße 52, 20246 Hamburg, Germany

Study Design

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

DOUBLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

40 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2018-01-08

Primary Completion

2019-11-30

Completion

2021-01-28

Countries

• Germany

Study Locations