Do Individual Differences in Gut Microbiota Impact Eating Disorders?

Asian American Woman or Girl Reading a Book

Eating disorders are often talked about from a social and psychological perspective, but they are also considered biological disorders. In fact, many biological factors, such as gut microbiota, can contribute to the development and maintenance of eating disorders.

Most recently, researchers from the Universities of Auckland, Finland, Latvia, and Estonia have examined the role that gut microbiota may play in these challenging disorders.

What Are Gut Microbiota?

The human body is an incredibly complex machine that is only as effective as the sum of its parts. One of these “parts” are called “gut microbiota,” the assemblage of microorganisms in the intestine [1]. These microorganisms act as defense systems in the body, helping it to recognize “friend from foe” and degrading toxic compounds [1].

They also play a very important role in digestion, working to break down dietary fiber that humans are not able to digest, facilitating the absorption of dietary minerals, and synthesizing essentials vitamins and amino acids [1]. When gut microbiota does not perform these functions, it can result in illnesses such as Crohn’s disease, irritable bowel syndrome, gastroparesis, asthma, diabetes, and many more.

Gut Microbiota & Mental Health

Like any machine, when one component does not function properly, the entire machine is thrown off. When there is an error in gut microbiota functioning, obviously physical health problems can arise. However, what is less known is that this can impact mental health.

“Most human gut bacteria do produce neurotransmitters, which are chemicals like dopamine and serotonin [2].” These chemicals influence intestinal functioning as well as mood and behavior.

Studies have found connections between gut microbiota functioning and mental health disorders such as anxiety, depression, autism spectrum disorder, and more. Researchers theorize that the decreased gut microbiota impacts serotonin and dopamine levels and, therefore, mood.

Relation to Eating Disorders

Doctor providing girl with a new prescription for gut microbiotaThe study mentioned above considered the relationship between gut microbiota and mental health and looked deeper into the relationship this may have with eating disorders. Researchers found that “when there are changes in gut microbiota, stress levels, and responsivity to stress, a patient’s symptoms and eating disorder diagnosis will change [2].” Essentially, changes in gut microbiota can be a trigger for emotional turbulence and disordered behaviors.

The study also, incredibly, found that “the difference between whether people are more likely to suffer bulimia nervosa (BN) or anorexia nervosa (AN) arises from the degree of neuroinflammation caused by chronic stress, with AN patients suffering stronger neuroinflammation than BN patients [2].” Study writers believe that neuroinflammation is one of the predominant biological mechanism that contributes to the variation between eating disorder diagnoses.

As a result, they have proposed a new evolutionary neurobiological model that answers four key questions:

  • Why symptoms and behaviors overlap across a range of eating disorders
  • Why diagnosing eating disorders is challenging
  • Why patient diagnoses may shift between different eating disorders over time
  • Why anorexia nervosa exists in two forms – fat-phobic and non-fat-phobic [2].

The ultimate hope is that further research will be conducted to determine how changes in gut microbiota are associated with eating disorder development, diagnosis, and possibly symptoms changes.


[1] Unknown (2020). Gut microbiota information. Gut Microbiota for Health by ESNM. Retrieved from

[2] Rantala, M. J., Luoto, S., Krama, T., Krams, I. (2019). Eating disorders: an evolutionary psychoneuroimmunological approach. Frontiers in Psychology.

About the Author:

Image of Margot Rittenhouse.Margot Rittenhouse, MS, PLPC, NCC is a therapist who is passionate about providing mental health support to all in need and has worked with clients with substance abuse issues, eating disorders, domestic violence victims, and offenders, and severely mentally ill youth.

As a freelance writer for Eating Disorder Hope and Addiction Hope and a mentor with MentorConnect, Margot is a passionate eating disorder advocate, committed to de-stigmatizing these illnesses while showing support for those struggling through mentoring, writing, and volunteering. Margot has a Master’s of Science in Clinical Mental Health Counseling from Johns Hopkins University.

The opinions and views of our guest contributors are shared to provide a broad perspective on eating disorders. These are not necessarily the views of Eating Disorder Hope, but an effort to offer a discussion of various issues by different concerned individuals.

We at Eating Disorder Hope understand that eating disorders result from a combination of environmental and genetic factors. If you or a loved one are suffering from an eating disorder, please know that there is hope for you, and seek immediate professional help.

Published August 20, 2020, on
Reviewed & Approved on August 20, 2020, by Jacquelyn Ekern MS, LPC

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