The Role of Gut Health in Eating Disorders

Holding Stomach

Contributor: Staff at Montecatini Eating Disorder Treatment Center

Eating disorders are widely known as mental health concerns, but experts continue to conduct research on the role of gut health in their development. While eating disorders have a lot to do with negative body image, low self-esteem, and co-occurring mental health disorders like anxiety and depression, there may also be some biological factors at play, like gut bacteria. Eating disorders themselves wreak havoc on the gut and can cause further damage if left untreated.

How Gut Bacteria Affects the Body

The body contains trillions of bacteria that are primarily located in the gut. These bacteria play an important role in overall health, communication with the immune system, the production of certain vitamins, and the chemicals that make you feel hungry or full.

Gut bacteria have been shown to affect weight loss and gain based on the amount and diversity present in the gut. One study found that obesity was associated with less diverse gut bacteria, meaning that the gut contained fewer types [1].

The body produces several different hormones that affect appetite, including leptin, ghrelin, and peptide YY. Different gut bacteria may affect how much of these hormones the body produces, controlling when someone feels hungry or full [1]. This can contribute to appetite dysregulation in individuals who have eating disorders.

Gut Bacteria and Psychological Conditions

Gut bacteria don’t just affect the body, but brain function as well. Dysbiosis, or an imbalance in gut bacteria, has been associated with major depressive disorder and depression behaviors. A study on patients who have major depressive disorder found that the patients had an unhealthy gut bacteria balance, with either higher levels of harmful gut bacteria or lower levels of beneficial bacteria [2].

Gut bacteria also produce neurotransmitters and neuromodulators that help control levels of anxiety and serotonin and regulate mood. Repeated use of antibiotics, which destroy bacteria (including beneficial groups), has been associated with an increase in symptoms of depression, anxiety, and other psychological concerns, like eating disorders [2].

In turn, the brain affects gut bacteria. The brain regulates gastrointestinal functions like nutrient absorption and acid production, shaping the gut environment. Psychological stress can change this environment, resulting in gut bacteria imbalance. Studies show that even small stressors like public speaking can cause intestinal problems [2]. Stress and other negative emotions are common triggers for eating disorder behaviors, so it’s no wonder so many of those who have eating disorders also have gut health concerns.



Call Montecatini for Help at 855-413-1587

How Eating Disorder Behaviors Can Affect the Gut

Up to 98% of those who have eating disorders meet the criteria for gastrointestinal disorders such as irritable bowel syndrome (IBS) [3]. This is due to behaviors like bingeing, purging, and restricting food intake. Restriction of food intake, as seen with eating disorders such as anorexia nervosa, can cause the gut to suffer almost immediately.

Pediatric gastroenterologist Mario Taño, M.D., explains the damage caused by eating disorders, stating, “If you don’t give yourself the appropriate amount of calories, there will be a prioritization of nutrients, and they go to the vital organs first” [3]. With the gut starved of nutrients, serious health problems can follow.

Not eating enough food also disrupts the body’s balance of good bacteria, hurting the immune system and worsening symptoms of IBS and other gastrointestinal conditions [3]. Restricting and purging can lead to gastroparesis, a condition where the stomach no longer contracts properly when breaking down food. This might result in a feeling of fullness well past a meal, reinforcing restrictive eating while causing malnourishment.

Treating Eating Disorders and Gut Health

Doctors often recommend elimination diets for those who have IBS and other gut issues to determine which foods may be causing the symptoms. However, when it comes to individuals who have eating disorders, elimination diets are likely to cause more harm than good. Doctors should address the eating disorder itself first to treat an unhealthy gut caused by eating disorder behavior.

In addition to providing mental health treatment, doctors should educate patients who have eating disorders on how to fill their diet with healthy whole foods, naturally gluten-free ingredients, and low-sugar choices [3].

Foods that are good for gut bacteria include:

  • Whole grains
  • Fruits and vegetables
  • Nuts and seeds
  • Dark chocolate
  • Fermented foods such as yogurt
  • Probiotics

Foods that may harm gut bacteria include:

  • Sugary foods
  • Artificial sweeteners
  • Unhealthy fats

Individuals who have eating disorders should seek proper mental healthcare to treat the source of their gut concerns. If you suspect that you might have an eating disorder that is affecting your gut health, help is available.

Dark Chocolate


[1] Robertson, R. (2018, February 13). How your gut bacteria can influence your weight. Healthline.

[2] Herpertz-Dahlmann, B., Seitz, J., & Baines, J. (2017). Food matters: How the microbiome and gut-brain interaction might impact the development and course of anorexia nervosa. European child & adolescent psychiatry26(9), 1031–1041.

[3] Russell, T. (2021, April 6). Up to 98% of eating disorder survivors have gut-health issues, but treating them requires extra care. Well and Good.

About Montecatini

Montecatini BannerMontecatini provides comprehensive treatment for women who are struggling with eating disorders and co-occurring mental health concerns. We provide a full continuum of life-changing care, including residential treatment, a partial hospitalization program (PHP), and an intensive outpatient program (IOP). We also offer a wellness center where clients can build healthier relationships with their bodies through joyful movement.

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 June 4, 2021, on
Reviewed & Approved on June 4, by Jacquelyn Ekern MS, LPC