Leaky gut syndrome describes a weakness in your intestinal barrier that may allow toxins to enter your bloodstream. This may cause hives and other skin problems in some people. Dietary changes may help.

Leaky gut syndrome is when the intestinal tract allows toxins to flow out of the gut into the bloodstream. It’s often associated with conditions of the digestive system, like inflammatory bowel disease (IBD).

Leaky gut can cause many symptoms, including hives. Diet changes, avoiding triggers, and treating underlying conditions may help you get rid of chronic hives.

Your intestines play an essential role in your overall health. They ensure that toxins and food particles stay out of your bloodstream while nutrients get through.

However, sometimes the intestinal barrier becomes “leaky,” allowing toxins to enter the bloodstream. Researchers call this intestinal permeability.

Cells in your intestines regulate the flow of water and molecules into nearby cells. But when the gut is “leaky,” inflammatory molecules move out. This can lead to increased inflammation and an immune response.

Researchers don’t know exactly what causes leaky gut. It can be a symptom of disorders such as IBD, but there’s no conclusive research that leaky gut is a condition on its own.

There’s some evidence that changes to your gut microbiome can cause leaky gut. Research suggests a possible link between changes in the microbiome and some autoimmune conditions, and leaky gut is often a symptom of autoimmune conditions.

Despite limited evidence, leaky gut has links to conditions such as:

There’s some evidence to show that what causes leaky gut may also have a link to hives.

A 2021 study compared the gut microbiome of 39 people with chronic hives with 40 people who do not experience hives. Those with chronic hives had different bacteria than those without. The study authors concluded that gut microbiome changes may be a factor in chronic hives.

What causes hives?

Hives are also called urticaria. Causes of hives include:

  • allergic reactions to dust, pollen, chemicals, or latex
  • eating certain foods
  • drinking alcohol or caffeine
  • infections
  • insect bites
  • exposure to heat or cold
  • itching or scratching of the skin from tight or itchy clothing
  • immune system dysfunction
  • antibiotics
  • nonsteroidal anti-inflammatory drugs (NSAIDs)
  • emotional stress

Leaky gut can lead to many symptoms, including those that affect your skin. According to the Canadian Digestive Health Foundation, other skin symptoms include:

A 2020 review of existing research found a link between the gut microbiome and skin health. Specifically, prior research showed gut microbiome differences in people with:

Chronic hives are when you get hives almost every day for 6 weeks or longer. According to the American Academy of Dermatology, about half of people with chronic hives stop having flares after 1 year.

A primary care doctor or dermatologist may be able to help you find relief. They can identify an underlying condition that may cause your hives. Examples include a thyroid condition, diabetes, or rheumatoid arthritis. Treating the condition may make your hives go away.

Sometimes, chronic hives come from allergies or the environment. Keeping a journal of when you get hives can help you track down a trigger or cause. Foods, medications, and allergens are all possible hive triggers. If you notice a link between a trigger and your symptoms, avoiding that trigger may resolve your hives.

To support your gut microbiome, you can eat a balanced diet of fresh foods. Some specific foods to help with gut bacteria include:

  • plant foods like vegetables, legumes, beans, and fruit
  • fermented foods like kimchi, sauerkraut, tempeh, and kefir
  • polyphenol-rich foods like dark chocolate, almonds, and green tea

You can also try removing foods from your diet if you think they may cause your hives. Some common triggers of chronic hives include:

  • wheat or gluten
  • seafood
  • alcohol
  • caffeine
  • eggs
  • nuts
  • tomatoes
  • food additives

If you have a latex allergy, foods like bananas, kiwis, and mangos can cause hives. You may also have personal triggers for hives caused by different foods, so a food diary can help you identify what foods to avoid.

Leaky gut syndrome is when weaknesses in the intestinal barrier allow toxins to flow into your bloodstream. Researchers aren’t sure whether leaky gut is its own condition or a symptom of other conditions like IBD.

Some people experience hives from leaky gut. They can find relief by avoiding foods that cause hives and eating a diet that supports the gut microbiome.