The Impact of Starvation on the Microbiome and Gut-Brain Interaction in Anorexia Nervosa

Jochen Seitz,Meriem Belheouane,Beate Herpertz-Dahlmann,John F. Baines,Astrid Dempfle,Nina Schulz

doi:10.3389/fendo.2019.00041

Jochen Seitz, Meriem Belheouane + Show 4 more

Open Access

https://doi.org/10.3389/fendo.2019.00041

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Abstract

Interactions between the gut microbiome and the brain are of increasing interest to both researchers and clinicians. Evidence is mounting on the causal role of an altered gut microbiome in inflammatory diseases such as arthritis, inflammatory bowel disease, obesity and diabetes, and psychiatric diseases like anxiety and depression. Mechanisms include altered energy harvest from food, hormonal changes, increased gut permeability, inflammation, immune response, and a direct influence on the brain and behavior. Anorexia nervosa (AN) is the third most common disease in adolescence and exacts a high burden on patients and caregivers. It often becomes chronic and has the highest mortality of all psychiatric diseases. As AN is characterized by nutritional restrictions, weight loss, and severe behavioral symptoms including weight phobia, comorbid anxiety and depression, accompanied by endocrine alterations, increased inflammation, and immune response, exploring the role of the gut microbiome is crucial. Here, we present an overview of the potential mechanisms of interaction between the gut microbiome, the host and particularly the brain in AN and summarize the initial findings of microbiome research on AN. We conclude by identifying future research directions and potential therapeutic approaches, including nutritional interventions, probiotics, prebiotics and food supplements, that could become important additions to current AN therapy.

Highlights

Anorexia nervosa (AN) is one of the most common chronic illnesses in adolescence, with a lifetime prevalence of 1–4% in 12–18-year-old girls in Europe [1]
Evidence is growing that AN-induced starvation is associated with profound alterations of the gut microbiome [10,11,12,13], which is of critical interest given its important interactions with the host metabolism in terms of weight regulation, hormonal, immunologic and inflammatory processes, along with a direct influence on the brain and behavior (“gut-brain axis”) [14,15,16,17,18]
Increased beta diversity was found for two groups [10, 11], showing an increased variability in the AN sample. This diversity decreased after weight rehabilitation, but importantly, the microbiome in the patients with AN more closely resembled their own microbiome before weight gain than that of the healthy controls [10]

Summary

INTRODUCTION

Anorexia nervosa (AN) is one of the most common chronic illnesses in adolescence, with a lifetime prevalence of 1–4% in 12–18-year-old girls in Europe [1]. Evidence is growing that AN-induced starvation is associated with profound alterations of the gut microbiome [10,11,12,13], which is of critical interest given its important interactions with the host metabolism in terms of weight regulation, hormonal, immunologic and inflammatory processes, along with a direct influence on the brain and behavior (“gut-brain axis”) [14,15,16,17,18] (see Figure 1). AN is one of the most “exemplary” disorders for studying gut-brain interactions because no other mental disease exists in which nutrition and its changes, which are important factors influencing microbial growth in the intestine, play such a crucial role [19]. Differences in the microbial species that extract energy from the same quantity of food could help explain why patients with the restrictive subtype require dramatically more calories to gain weight compared to patients with the binge-purging subtype [39]

INTESTINAL PERMEABILITY

INITIAL FINDINGS OF AN

CONSEQUENCES FOR FUTURE RESEARCH AND THERAPEUTIC OUTLOOK