Anorexia nervosa and inflammatory bowel diseases—Diagnostic and genetic associations

Inpatient admissions and mortality of anorexia nervosa patients according to their preceding psychiatric and somatic diagnoses

OBJECTIVE

Anorexia nervosa (AN) is associated with increased risk of mortality, but little is known about the risk of inpatient admissions and mortality outcomes in individuals with diagnoses of both AN and other psychiatric and somatic conditions. We aimed to investigate the inpatient admissions and mortality among people with AN and other diagnosed conditions using Danish national registers.

METHOD

This retrospective cohort study included individuals diagnosed with AN in Denmark, born 1977-2010. We identified other mental and somatic conditions in this population. We used Cox proportional hazards regression to estimate the risk of inpatient admission and mortality, focusing on (i) the number of other diagnosed conditions, and (ii) specific combinations of conditions diagnosed prior to the AN diagnosis. Categories of inpatient admissions considered were due to: (i) AN, (ii) any psychiatric disorder, and (iii) any somatic disorder. Additionally, competing risks survival analysis was used to calculate the cumulative incidence of inpatient admission and all-cause mortality over the follow-up period.

RESULTS

The study population included 11,489 individuals. The most common conditions individuals had prior to their AN diagnosis were other eating disorders (34.5%) and anxiety disorders (32.7%). During the follow-up, 3184 (27.7%), 4604 (40.1%), and 6636 (57.8%) individuals were admitted for AN, any psychiatric disorder, and any somatic disorder, respectively; and in total 106 (0.9%) died. The risk of all outcomes was highest among those who had received a higher number of other diagnoses. For most combinations, the risks of admission and mortality were increased.

DISCUSSION

Our study presents the prevalence of other conditions in patients with AN in Denmark and elucidates their association with higher rates of inpatient admission and mortality. Our findings highlight the need for comprehensive, multidisciplinary care of patients with AN considering the spectrum of other diagnosed conditions to improve health outcomes.

Influence of the gut microbiome on appetite-regulating neuropeptides in the hypothalamus: Insight from conventional, antibiotic-treated, and germ-free mouse models of anorexia nervosa

Recent research highlights the profound impact of the gut microbiome on neuropsychiatric disorders, shedding light on its potential role in shaping human behavior. In this study, we investigate the role of the gut microbiome in appetite regulation using activity-based anorexia (ABA) mouse model of anorexia nervosa (AN) - a severe eating disorder with significant health consequences. ABA was induced in conventional, antibiotic-treated, and germ-free mice. Our results show the clear influence of the gut microbiome on the expression of four orexigenic (neuropeptide Y, agouti-related peptide, melanin-concentrating hormone, and orexin) and four anorexigenic peptides (cocaine- and amphetamine-regulated transcript, corticotropin-releasing hormone, thyrotropin-releasing hormone, and pro-opiomelanocortin) in the hypothalamus. Additionally, we assessed alterations in gut barrier permeability. While variations were noted in germ-free mice based on feeding and activity, they were not directly attributable to the gut microbiome. This research emphasizes that the gut microbiome is a pivotal factor in AN's appetite regulation beyond just dietary habits or physical activity.

Gastrointestinal symptoms, gut microbiome, probiotics and prebiotics in anorexia nervosa: A review of mechanistic rationale and clinical evidence

Recent research has revealed the pivotal role that the gut microbiota might play in psychiatric disorders. In anorexia nervosa (AN), the gut microbiota may be involved in pathophysiology as well as in the gastrointestinal (GI) symptoms commonly experienced. This review collates evidence for the potential role of gut microbiota in AN, including modulation of the immune system, the gut-brain axis and GI function. We examined studies comparing gut microbiota in AN with healthy controls as well as those looking at modifications in gut microbiota with nutritional treatment. Changes in energy intake and nutritional composition influence gut microbiota and may play a role in the evolution of the gut microbial picture in AN. Additionally, some evidence indicates that pre-morbid gut microbiota may influence risk of developing AN. There appear to be similarities in gut microbial composition, mechanisms of interaction and GI symptoms experienced in AN and other GI disorders such as inflammatory bowel disease and functional GI disorders. Probiotics and prebiotics have been studied in these disorders showing therapeutic effects of probiotics in some cases. Additionally, some evidence exists for the therapeutic benefits of probiotics in depression and anxiety, commonly seen as co-morbidities in AN. Moreover, preliminary evidence for the use of probiotics in AN has shown positive effects on immune modulation. Based on these findings, we discuss the potential therapeutic role for probiotics in ameliorating symptoms in AN.