Ask the Dietitian: What’s the Connection Between PsA and IBD?

Many people with PsA experience gut symptoms, both in and out of a flare. Dietitian Laura Krebs-Holm explores the connection between PsA, IBD, and gut health.

Psoriatic arthritis (PsA) impacts people in many unique ways. It’s both a chronic inflammatory disease and an autoimmune disease that affects the ligaments and tendons that connect to your bones. About 30% of people with psoriasis develop PsA.

Several comorbidities are associated with PsA, like cardiovascular disease, fibromyalgia, metabolic syndrome, and inflammatory bowel disease (IBD).

Many people with PsA experience gut symptoms, both in and out of a flare. Let’s explore the link between PsA, IBD, and gut health.

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IBD and PsA

Research has found some connection between PsA and IBD.

A 2022 study found a causal link between IBD and psoriasis. People with IBD were much more likely to develop psoriasis than people without IBD. The same was true for PsA. There was also some evidence that people who already had psoriasis were more likely to develop Crohn’s disease, a type of IBD.

Previous research has established that patients diagnosed with PsA or psoriasis have a one to four times greater chance of developing IBD than those without the disease.

A 2021 study found that people with a type of spondyloarthritis (SpA) like PsA were likely to have gastrointestinal inflammation. The lesions caused by this inflammation made it more likely for a person to develop IBD. The study also found that the more severe a person’s PsA, the more likely they were to develop IBD.

PsA and gut health

There’s been a lot more attention on gut health in recent years. The microbiome — the community of bacteria and organisms in our gut — can greatly attribute to our health. It affects how we digest food, absorb vitamins and minerals, and more.

In particular, gut health can impact how microbes interact with our immune system. It can influence how the immune system marks the difference between good bacteria and germs that can make us sick.

A 2015 study found that people with PsA had gut microbiomes that looked extremely similar to those with IBD. Both groups (PsA and IBD) had less diversity in their microbiome than a healthy control group. Additionally, a disruption in the gut bacteria was associated with chronic inflammatory disorders of the skin, like psoriasis.

The microbiome in people with IBD is generally less diverse than in healthy groups. It may then disrupt the barrier of the colon and allow bacteria to pass into the entire body system, potentially leading to inflammation.

Some professionals hypothesize that probiotics may be beneficial, but more research is needed into the type of probiotics, the dosage, and the therapeutic target of the probiotics.

What is polyautoimmunity?

It’s worth mentioning the concept of polyautoimmunity when talking about a link between PsA and IBD. Polyautoimmunity is the diagnosis of more than one autoimmune disease in a single person. If a person has three or more autoimmune diseases, it’s called multiple autoimmune syndrome (MAS).

There is evidence that different autoimmune diseases share some signs and symptoms, organ function, and genetic and environmental favors. The idea that these different diseases may have a common origin is called autoimmune tautology.

Autoimmune tautology may help to explain why people diagnosed with PsA or psoriasis may also be diagnosed with other autoimmune diseases like Crohn’s disease or ulcerative colitis, two common types of IBD.

The takeaway

If you have PsA, you may have noticed that your bathroom habits change during a flare. You may wonder if you’re at risk for developing IBD. Some research suggests a link between PsA, IBD, and gut health.

People with PsA should eat a diet rich in fruits, vegetables, and whole grains, all of which contain fibers that promote healthy gut bacteria growth. You can also incorporate foods in your diet that contain probiotics naturally, like fermented foods. Yogurt, kefir, kimchi, sauerkraut, and kombucha all contain probiotics.

If you’re experiencing changes in your gut health, keeping a journal of your symptoms and anything else noteworthy, like your diet or PsA flares, is helpful. Talk with your doctor or see a gastroenterologist if you have concerns.