Anorexia nervosa gut bacteria different due to eating disorder

Anorexia nervosa gut bacteria different due to eating disorderResearchers have found that the gut microbiota in individuals with anorexia nervosa is different than those without the eating disorder. Anorexia nervosa is an eating disorder where individuals refuse to maintain a healthy body weight, have an intense fear of gaining weight and possess a distorted body image.

Mealtimes for individuals with anorexia nervosa can be quite stressful, and typically these individuals will try and avoid eating in front of others. Food and weight become an obsession for those with anorexia nervosa and it occupies their whole day. Furthermore, these individuals feel they are never skinny enough, and thus the eating disorder takes over.


Anorexia nervosa involves not eating or using laxatives or vomiting as a means to purge foods that may have been eaten. Researchers have now found that this process drastically changes the microbiota within the gut.

Gut bacteria population, diversity linked to anorexia nervosa

Gut bacteria population, diversity linked to anorexia nervosaResearchers at the University of North Carolina School of Medicine found that individuals with anorexia nervosa have very different microbial communities within their gut in comparison to those without the eating disorder. Gut microbiota are the trillions of bacteria affecting digestive and immune health. Gut microbiota can also affect what is referred to as the “gut-brain axis.” Researchers believe this gut bacteria can help reduce the symptoms associated with anorexia nervos,a which affects the lives of more than three million Americans.

Senior author of the study, Ian Carroll, Ph.D., said, “Other studies have linked gut bacteria to weight regulation and behavior. Since people with anorexia nervosa exhibit extreme weight dysregulation, we decided to study this relationship further.” He added, “We’re not able to say a gut bacterial imbalance causes the symptoms of anorexia nervosa, including associated symptoms, such as anxiety and depression. But the severe limitation of nutritional intake at the center of anorexia nervosa could change the composition of the gut microbial community. These changes could contribute to the anxiety, depression, and further weight loss of people with the disorder. It’s a vicious cycle, and we want to see if we can help patients avoid or reverse that phenomenon. We want to know if altering their gut microbiota could help them with weight maintenance and mood stabilization over time.”

The team collected fecal samples from 16 women suffering from anorexia nervosa when they were first admitted to a treatment center, and then once again when they gained a healthy amount of weight back. Each sample was characterized by composition and diversity of gut bacteria.

Vast differences were seen from when the women were first admitted to when they had restored their weight. Initial samples had fewer varieties of gut bacteria, which made the intestinal communities less diverse. Microbial variety is an indicator of good health. Once the women were discharged microbial variety had increased, although it was still less when compared to healthy individuals.

As microbial variety improved so did symptoms related to anorexia nervosa, including improvement in mood, prompting researchers to question if gut bacteria variety could relieve symptoms in anorexia nervosa.

Carroll said, “Over the past 10 years, prominent researchers have learned that when you take gut microbial communities of an obese person and put it in germ-free mice – which are maintained in sterile conditions and lack intestinal microbiota – the mice gain more weight than germ-free mice that have been colonized with a gut microbiota from a lean individual. This suggests that gut microbes mediate weight gain or loss.”

Carroll believes that in the future altering gut bacteria may aid in treatment of anorexia nervosa – although he doesn’t believe it is a tell-tall cure, it definitely has potential.

Cynthia Bulik, a member of the research team, concluded, “In addition, the process of weight gain and renourishment can be extremely uncomfortable for patients. Often, patients are discharged from the hospital, and within months and sometimes weeks they find themselves losing weight again and facing readmission. If specific alterations in their microbiota could make renourishment less uncomfortable, help patients regulate their weight, and positively affect behavior, then we might see fewer readmissions and more cures.”

How anorexia affects the body

We all know that anorexia nervosa affects weight – more importantly, it contributes to significant and dangerous weight loss. But anorexia can affect the body in many other ways as well, including:

  • Severe mood swings, depression
  • Lack of energy and weakness
  • Slow thinking, poor memory, trouble concentrating
  • Dry, yellowish skin and brittle nails
  • Constipation and bloating
  • Tooth decay and gum damage
  • Dizziness, fainting and headaches
  • Growth of fine hair all over the body
  • Blood problems including anemia
  • Low blood pressure, slow heart rate, heart palpitations, heart failure
  • Hair thinning
  • Kidney stones, kidney failure
  • Stoppage of periods
  • Bone loss
  • Trouble getting pregnant
  • Easily bruising skin
  • Low body temperature, gets cold easily

Nutrition for healthy gut to avoid anorexia effects

Having an eating disorder can set you up for vitamin and nutrient deficiencies. Vitamin deficiencies can contribute to many of the negative effects of anorexia nervosa, for example, memory fog.

In order to begin restoring the body and combating the negative effects of anorexia, it’s important to follow these tips:

  • Avoid caffeine, alcohol and tobacco.
  • Drink plenty of water.
  • Consume quality protein sources, such as eggs, meat, whey and vegetable protein.
  • Avoid refined sugars, such as candy and soft drinks.
  • Take a daily vitamin.
  • Increase your omega-3 fatty acids.
  • Boost your Coenzyme Q10.
  • Take a probiotic.
  • Eat Jerusalem artichokes, bananas, polenta, cruciferous vegetables, blueberries, beans and fermented plant-based foods in order to increase variety of gut bacteria.

Understanding the symptoms of anorexia nervosa

Symptoms of anorexia nervosa can be categorized as cognitive, emotional, behavioral and physical.

Understanding the symptoms of anorexia nervosaCognitive symptoms

  • Obsessive with food
  • Creating rules for themselves – weighing servings, counting crunches – and becoming upset if they don’t follow their rules
  • Perfectionists
  • Denial of a problem
  • Symptoms are an expression of “free will”

Emotional symptoms

  • Feelings of shame
  • Low mood
  • Anxiety related to hair loss but not about potential death

Behavioral symptoms 

  • Binge eating followed by purging
  • Eating rituals – for example, eating in the same spot at the same time
  • Avoiding social eating
  • Wearing baggy clothing
  • Lying about eating
  • Frequently weighing themselves
  • Spending more time studying or working due to poor concentration
  • Avoiding “forbidden foods”

Physical symptoms

  • Hair loss
  • Slow heartbeat, heart damage
  • Bone density loss
  • Fine hair growth all over body
  • Poor circulation, constantly feeling cold to the touch
  • Body mass index (BMI) under 19
  • Irregular or stopped periods

Prevention and treatment for anorexia nervosa

Healthy eating habits and supporting a healthy body image are effective means to help prevent anorexia nervosa. Society places unrealistic expectations onto females, which unfortunately, they feel they need to achieve. Having open discussions with your daughter or friend who may be struggling with body image issues can also help them talk through what may be bothering them. Education, then, is an important tool in the prevention of anorexia.

If a person has been diagnosed with anorexia or is recovering from it, here are some tips to keep in mind as well.

  • Do not focus on their condition, on food or weight. Meal times should be relaxing and a time to socialize.
  • Watch for signs of relapse – frequent checking of weight, avoidance of eating in public, etc.
  • Have them seek out therapy – cognitive behavioral therapy can be helpful.
  • Consider attending family therapy so you can find ways to better support the individual as well.

Related Reading:

 Know the causes and symptoms of binge eating disorder

 Binge eating disorder is a serious eating disorder where you frequently consume unusually large amounts of food. What is binge eating disorder? When those second or third helpings associated with overeating cross the line and become part of your routine, this could be binge eating disorder. Continue reading…


Seniors: Eating disorders not just for teenagers

 Eating disorders are more prevalent than ever among young girls desperately trying to fit the beauty mold. A full 25 percent of college-aged women in America engage in bingeing and purging as a weight-management technique, according to the National Association of Anorexia Nervosa and Associated Disorders (ANAD). Continue reading…


Author Bio

Emily Lunardo studied medical sociology at York University with a strong focus on the social determinants of health and mental illness. She is a registered Zumba instructor, as well as a Canfit Pro trainer, who teaches fitness classes on a weekly basis. Emily practices healthy habits in her own life as well as helps others with their own personal health goals. Emily joined Bel Marra Health as a health writer in 2013.