Impulsivity and compulsivity are related to emotional and social maladjustment and
often underlie psychiatric disorders. Recently, alterations in microbiota composition
have been shown to have implications for brain development and social behavior via
the microbiota-gut-brain axis. However, the exact mechanisms are not fully identified.
Recent evidence suggests the modulatory effect of synbiotics on gut microbiota and
the contribution of these agents in ameliorating symptoms of many psychiatric diseases.
To date, no randomized controlled trial has been performed to establish the feasibility
and efficacy of this intervention targeting the reduction of impulsivity and compulsivity.
We hypothesize that supplementation with synbiotics may be an effective treatment
in adults with high levels of impulsivity and/or compulsivity.This is a prospective,
multicenter, double-blind, randomized controlled trial with two arms: treatment with
a synbiotic formula versus placebo treatment. The primary outcome is the response
rate at the end of the placebo-controlled phase (response defined as a Clinical Global
Impression-Improvement Scale score of 1 or 2 = very much improved or much improved,
plus a reduction in the Affective Reactivity Index total score of at least 30% compared
with baseline). A total of 180 participants with highly impulsive behavior and a diagnosis
of attention deficit/hyperactivity disorder (ADHD) and/or borderline personality disorder,
aged 18-65 years old, will be screened at three study centers. Secondary outcome measures,
including changes in general psychopathology, ADHD symptoms, neurocognitive function,
somatic parameters, physical activity, nutritional intake, and health-related quality
of life, will be explored at assessments before, during, and at the end of the intervention.
The effect of the intervention on genetics, microbiota, and several blood biomarkers
will also be assessed. Gastrointestinal symptoms and somatic complaints will additionally
be explored at 1-week follow-up.This is the first randomized controlled trial to determine
the effects of supplementation with synbiotics on reducing impulsive and compulsive
behavior. This clinical trial can contribute to explaining the mechanisms involved
in the crosstalk between the intestinal microbiome and the brain. If effects can be
established by reducing impulsive and compulsive behavior, new cost-effective treatments
might become available to these patients.ClinicalTrials.gov, NCT03495375. Registered
on 26 February 2018.
