ABSTRACT
Introduction
Host–microbiota interactions may be involved in many physical and psychological functions ranging from the digestion of food, maintenance of immune homeostasis, to the regulation of mood and cognition. Microbiome dysbiosis has been consistently described in many diseases. The pathogenesis and weight regulation mechanism in anorexia nervosa (AN) also seem to be implicated in the dynamic bidirectional adjustment of the microbiota-gut-brain axis. This review aims at elucidating this relationship.
Area covered
This review starts with a description of pathogenic gut-brain pathways. Next, we focus on the latest research on the associations between gut microbiota and weight change in the condition of AN. The strategies to alter the intestinal microbiome for the treatment of this disorder are discussed, including dietary, probiotics, prebiotics, synbiotics, and fecal microbiota transplantation.
Expert opinion
Gut microbiome is inextricably linked to AN. It may regulate weight gain in the process of refeeding via the microbiota-gut-brain axis, while the specific mechanism has yet to be clearly established. In the future, a better understanding of gut microbiome could have implications for developing microbiome-based prevention, diagnostics and therapies.
Abbreviations
AN: anorexia nervosa
AN-R: anorexia nervosa restricting type
AN-BP: anorexia nervosa binge-eating/purging type
GI: gastrointestinal
CNS: central nervous system
IBS: irritable bowel syndrome
HPA: hypothalamic-pituitary-adrenal
CAR: cortisol awakening response
GF: germ-free
LPS: lipopolysaccharide
ABA: activity-based anorexia
BBB: blood–brain barrier
TNF: tumor necrosis factor
IL: interleukin
FMT: fecal microbiota transplantation
SCFA: short-chain fatty acid
F/B ratio: Firmicutes/Bacteroidetes ratio
Acknowledgments
The authors would like to thank all the staff of the Department of Clinical Psychology, Shanghai Mental Health Center for their support. This article was proofread by Shuxin Cao and Xudong Shen.
Article highlights
Anorexia nervosa is a debilitating multifactorial condition in which gut microbiome dysbiosis has been observed.
Gut microbiome may transmit endocrine, vagus nerve and immune signals to the brain via the microbiota-gut-brain axis, thereby contributing to the mechanisms and behaviors typical of anorexia nervosa.
Gut microbiome may regulate weight change in people with anorexia nervosa, normal weight and obesity.
Novel treatments targeting microbiome hold great promise for improving outcomes of anorexia nervosa, while more research is necessary.
Declaration of interest
The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or conflict with the subject matter or materials discussed in this manuscript apart from those disclosed.
Reviewer disclosures
Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.