Alcohol use disorder (AUD) is a major public health problem affecting 5 to 10% of the population. Chronic alcohol abuse induces alterations in the composition of the gut microbiota, which are correlated with psychological symptoms, suggesting the involvement of the gut-brain axis in the development of addiction. Among dietary component able to modulate the microbiota, dietary fibers are of particular interest. In a first study we investigated the link between dietary fiber intake and psychological symptoms in AUD patients. We found that only a proportion of AUD patients displays alterations in the gut microbiota composition. This dysbiosis is associated with higher craving scores and impaired sociability. Finally, our intervention study aiming to supplement AUD patients with inulin shows that 1) it does not lead to gastro-intestinal intolerance, 2) it induces specific changes in the gut microbiota, 3) it has limited impact on biological and behavioural outcomes, 4) it increases sociability score. If our results show the importance of prebiotic dietary fiber in AUD patients, further studies are needed to define an adapted strategy targeting the gut microbiota to improve metabolic and behavioural alterations in these patients.