Exploring the Gut Microbiome Changes Associated with Anorexia Nervosa

Stephan Ahearn^*
*Correspondence: Stephan Ahearn, Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA, Email:

Keywords

Anorexia nervosa • Gut microbiome • Gut dysbiosis

Introduction

Anorexia Nervosa (AN) is a complex psychiatric disorder characterized by restricted food intake, an intense fear of gaining weight, and a distorted body image. While its etiology remains multifaceted, recent research has begun to uncover the potential role of the gut microbiome in the development and progression of AN. The gut microbiome, comprising trillions of microorganisms residing in the gastrointestinal tract, plays a crucial role in various physiological functions, including metabolism, immune modulation, and brain-gut communication. This article aims to provide an extensive review of the gut microbiome changes associated with AN, shedding light on potential implications for understanding and treating this challenging disorder.

Literature Review

Studies have consistently reported alterations in the composition and diversity of the gut microbiota in individuals with AN compared to healthy controls. Dysbiosis, characterized by shifts in the relative abundance of specific microbial taxa, is a hallmark feature observed in AN. Several key findings have emerged from microbiome studies in AN: Reduced Microbial Diversity: Individuals with AN often exhibit lower microbial diversity in their gut microbiota, with decreased richness and evenness compared to healthy individuals. This reduction in diversity may compromise the resilience and functional capacity of the microbiome, potentially impacting host health [1].

AN is associated with changes in the relative abundance of various microbial taxa. While findings have been somewhat inconsistent across studies, some trends have been observed. For instance, a decrease in the abundance of bacterial taxa involved in carbohydrate metabolism, such as Firmicutes, has been reported in AN. Conversely, certain bacterial genera, including Bacteroidetes and Proteobacteria, may be overrepresented in individuals with AN. Functional Alterations: Beyond taxonomic changes, alterations in the functional capacity of the gut microbiome have also been noted in AN. Metagenomic and metatranscriptomic analyses have revealed shifts in microbial pathways involved in energy metabolism, nutrient absorption, and neurotransmitter synthesis. These functional changes may contribute to the metabolic and neurobehavioral disturbances observed in AN [2].

Discussion

The mechanisms driving gut microbiome dysbiosis in AN are likely multifactorial and interconnected. Several factors may contribute to these alterations, including:

The restrictive eating behaviors characteristic of AN can directly impact the composition and diversity of the gut microbiota. Prolonged calorie restriction and selective food avoidance may create an environment conducive to the proliferation of certain microbial taxa while suppressing others [3].

AN is associated with gastrointestinal disturbances, such as delayed gastric emptying and intestinal motility disorders. These physiological changes may disrupt the gut environment, altering nutrient availability, mucosal integrity, and microbial-host interactions.

Psychological stress is a common feature of AN and can exert profound effects on the gut-brain axis. Stress-induced alterations in gut motility, intestinal permeability, and immune function may contribute to microbiome dysbiosis in individuals with AN [4].

Emerging evidence suggests that AN is characterized by dysregulated immune responses, including low-grade inflammation and altered cytokine profiles. Immune-mediated mechanisms may influence gut microbiome composition and function, creating a feedback loop that perpetuates dysbiosis.

Understanding the gut microbiome changes associated with AN holds promise for improving diagnostic approaches, developing targeted interventions, and predicting treatment outcomes [5].

Gut microbiome signatures may serve as potential biomarkers for AN, aiding in early detection, differential diagnosis, and treatment monitoring. Machine learning algorithms and multi-omics approaches offer opportunities to identify robust microbial signatures associated with AN.

Modulating the gut microbiota through dietary interventions, probiotics, prebiotics, or Fecal Microbiota Transplantation (FMT) represents a novel therapeutic avenue for AN. Targeting microbial dysbiosis may help restore gut homeostasis, alleviate gastrointestinal symptoms, and improve metabolic and psychological outcomes in individuals with AN.

Recognizing the heterogeneity of gut microbiome alterations in AN, personalized treatment strategies tailored to individual microbiome profiles may enhance therapeutic efficacy and long-term recovery outcomes [6].

Conclusion

In summary, accumulating evidence implicates gut microbiome dysbiosis in the pathophysiology of AN. Future research endeavors aimed at elucidating the complex interactions between the gut microbiota, host physiology, and environmental factors in AN are warranted. By deciphering the mechanistic underpinnings of microbiome alterations in AN, we may uncover novel avenues for diagnosis, treatment, and prevention, ultimately improving the lives of individuals affected by this debilitating disorder.

Acknowledgement

None.

Conflict of Interest

None.

References

1. Valdes, Ana M., Jens Walter, Eran Segal and Tim D. Spector. "Role of the gut microbiota in nutrition and health." Bmj 361 (2018).

   Google Scholar, Crossref, Indexed at

2. Zafar, Hassan and Milton H. Saier Jr. "Gut Bacteroides species in health and disease." Gut microbes 13 (2021): 1848158.

   Google Scholar, Crossref, Indexed at

3. Consortium, Human Microbiome Project. "Structure, function and diversity of the healthy human microbiome." Nature 486 (2012): 207-214.

   Google Scholar, Crossref, Indexed at

4. Kelly, John R., Yuliya Borre, Ciaran O'Brien and Elaine Patterson, et al. "Transferring the blues: depression-associated gut microbiota induces neurobehavioural changes in the rat." J Psychiatr Res 82 (2016): 109-118.

   Google Scholar, Crossref, Indexed at

5. Zheng, Peng, B. Zeng, C. Zhou and M. Liu, Z. Fang, et al. "Gut microbiome remodeling induces depressive-like behaviors through a pathway mediated by the host’s metabolism." Mol Psychiatry 21 (2016): 786-796.

   Google Scholar, Crossref, Indexed at

6. Seitz, Jochen, Meriem Belheouane, Nina Schulz and Astrid Dempfle, et al. "The impact of starvation on the microbiome and gut-brain interaction in anorexia nervosa." Front Endocrinol 10 (2019): 41.

   Google Scholar, Crossref, Indexed at