The Microbiota, the Gut and the Brain in Eating and Alcohol Use Disorders: A ‘Ménage à Trois’?

Abstract

Aims: Accumulating evidence for the influence of the gut microbiota on the bidirectional communication along the gut-brain axis suggests a role of the gut microbiota in eating disorders (EDs) and alcohol and substance use disorders. The potential influence of altered gut microbiota (dysbiosis) on behaviors associated with such disorders may have implications for developing therapeutic interventions. Methods: A systematic review of preclinical and clinical studies evaluating the gut microbiota, EDs and alcohol and substance use disorders was conducted using MEDLINE, Embase and Web of Science databases with the objective being to examine the role of the gut microbiota in behavioral correlates of these disorders. Original papers focused on the gut microbiota and potential behavioral implications were deemed eligible for consideration. Results: The resulting 12 publications were limited to gut microbiota studies related to EDs and alcohol and substance use disorders. Some studies suggest that dysbiosis and gut microbial byproducts may influence the pathophysiology of EDs via direct and indirect interference with peptide hormone signaling. Additionally, dysbiosis was shown to be correlated with alcohol use disorder-related symptoms, i.e. craving, depression and anxiety. Finally, a mouse study suggests that manipulations in the gut microbiota may affect cocaine-related behaviors. Conclusions: Promising, albeit preliminary, findings suggest a potential role of the gut microbiota in behavioral correlates of EDs and alcohol and substance use disorders. Short summary: Preliminary evidence exists supporting the role of the gut microbiota in eating disorders and alcohol and substance use disorders, although additional investigation is needed to determine what is causative versus epiphenomenological.

Ghrelin receptor deletion reduces binge‐like alcohol drinking in rats

“…Recent studies also indicate that the gut‐microbiome may influence behaviours in alcohol and substance use disorder . For example, diminished microbiome diversity in mice led to increased cocaine‐induced conditioned place preference and locomotor sensitivity .…”

Gut microbiome correlates with altered striatal dopamine receptor expression in a model of compulsive alcohol seeking

“…One strategy would consist of better identifying "problem drinkers" in the general population who are not yet manifesting major symptoms of heavy intoxication but are drinking at levels that increase risks for medical and psychosocial consequences (Saitz, 2009). Growing evidence points out to a role of the microbiotagut-brain axis in AUD, with excessive ethanol consumption altering the gut microbiome, increasing the intestinal permeability and exacerbating systemic inflammation, ultimately amplifying comorbidities classically observed in alcoholic patients (Bull-Otterson et al, 2013;de Timary et al, 2015;Gorky and Schwaber, 2016;Leclercq et al, 2017Leclercq et al, , 2014aLeclercq et al, , 2014bLeclercq et al, , 2012Temko et al, 2017).…”

Liver Injury, Endotoxemia, and Their Relationship to Intestinal Microbiota Composition in Alcohol‐Preferring Rats

“…In view of bidirectional communication along the gut–brain axis, imbalances or alterations in intestinal microbial composition may play a role in AUD (Temko et al., ). While the intestinal microbiota (IM) and human health are inextricably linked (Bäckhed et al., ), disruption of normal intestinal microflora (i.e., intestinal dysbiosis) can negatively affect the host's ability to respond to stressors (Schnabl and Brenner, ).…”