Anxiety and Gut Health, What’s the Link?

Remember that uneasiness you felt in your stomach when you had to give a sales presentation before the boss or the butterflies in your stomach before a big road race? Do your symptoms of irritable bowel syndrome flare up when you’re nervous? These are just a few indicators of the link between anxiety and gut health.

What is anxiety?

Before we explore the two-way street between anxiety and gut health, let’s better understand this most common mental illness in the United States.

Anxiety affects about 40 million adults, or 18.1 percent of the population. The majority of people with anxiety have generalized anxiety disorder, with women being twice as likely to be affected as men.

About 6 million people suffer with panic attacks, and again women are affected more. Social anxiety disorder is an equal opportunity mental condition that affects about 15 million adults.

Even though anxiety is common and highly treatable, less than 40 percent of people who have any type of anxiety disorder get treated. Since men tend to be less likely to seek any type of medical treatment, it would seem many men are going untreated.

Understanding gut health

The gut hosts about 70 percent of the body’s immune system. The gut is populated by trillions of bacteria, also known as the gut microbiome. These bacteria help the immune system’s T cells discern between invading substances and the body’s own tissues. Obviously this is an extremely important task, because cells that don’t make this distinction can end up destroying healthy tissue, resulting in autoimmune disorders.

In addition to immune cells, your gut also harbors more than 100 million brain cells. This phenomenon has earned the gut the title of the “second brain,” also known as the enteric nervous system (ENS). The ENS consists of two layers of these 100 million-plus cells that line the gut from the esophagus to the rectum.

The gut also houses 95 percent of the 95 percent of the serotonin in your body. Serotonin is a neurotransmitter and hormone that plays a critical role in mood, and well-being, but also has a role in eating and digestion. This makes serotonin one of the major players in the link between anxiety and gut health..

Research on anxiety and gut health

Numerous studies support the intimate connection between anxiety and a healthy bacterial environment in your gut. Research indicates that the connection works both ways; that is, anxiety can cause gut problems and gut/digestive problems can cause anxiety and depression.

For example, the ENS can trigger emotional responses in individuals who are living with IBS or issues such as constipation, bloating, stomach upset, or diarrhea. According to Jay Pasricha, MD, director of the Johns Hopkins Center for Neurogastroenterology, experts long believed that anxiety contributed to IBS and other digestive problems. “But our studies and others show that it may also be the other way around,” he explains. Researchers are discovering that gut problems may send signals to the central nervous system, which in turn sparks mood changes.

In other research, experts conducted an analysis of 21 studies (more than 1,500 participants) and found that in 52 percent of the studies, when people regulated the bacteria in their gut, it helped reduce anxiety. Use of probiotics was one way individuals regulated their gut health.

However, study participants who made dietary changes (i.e., followed a low FODMAP eating program) actually fared better than those who took probiotics. FODMAP (fermentable oligo-, di-, mono-saccharides and polyols) are short-chain carbohydrates (e.g., wheat [gluten], beans, dairy products) that are not adequately absorbed by the small intestine. The result can be a variety of gut problems such as diarrhea, constipation, stomach pain, gas, and bloating.

In a report by Randi Fredricks, PhD, he notes that “it is probably no surprise that stomach issues can cause stress, but they can also lead to significant mental health problems.” Gut problems most likely to be associated with anxiety are those such as irritable bowel syndrome (IBS). Studies show that individuals who have irritable bowel syndrome experience worsening of symptoms when they are anxious.

Among the 20 percent of Americans who experience recurring or persistent gut pain, including IBS, it’s been shown that these individuals are significantly more likely to also have anxiety or depression.

Bottom line

The connection between anxiety and gut health is a topic that warrants much research. Experts are learning more and more every day about how the two brains—the one in our head and the one in our gut—communicate with each other and have a significant impact on our overall health. Some research even suggests gut health has an effect on memory and cognition as well. Clearly the anxiety and gut health connection is one to keep your eye on.


Anxiety and Depression Association of America. Facts and statistics.

Blum S MD. What healing your gut can do for your immune system. MindBodyGreen

Fredricks R, PhD. Can gastric disorders contribute to anxiety and depression. Mental Health Net

Johns Hopkins Medicine. The brain-gut connection.

Yang B et al. Effects of regulation intestinal microbiota on anxiety symptoms: a systematic review. General Psychiatry 2019 May 17; 32(2): e100056

by Mens Health Editor

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