October 25, 2026, 7 a.m. ET
If you’ve ever dealt with persistent bloating, stomach upset, or diarrhea, you may have wondered if “leaky gut” could be the cause — especially since it’s often talked about on social media.
Although intestinal permeability is real, “leaky gut syndrome itself is not currently recognized as an official medical diagnosis,” says Dr. Jason Nagata, a physician at UCSF Benioff Children’s Hospital in San Francisco.
Yet when people talk about “intestinal permeability,” they are usually referring to this increased intestinal permeability, which is the medical description of how substances pass through the intestinal lining that normally allows nutrients and water to enter the bloodstream while helping to keep bacteria and other potentially harmful substances out.
Here’s what can happen when this lining becomes inflamed or injured, letting in substances that would normally be kept out.
What is leaky gut?
Your intestinal lining is not meant to be completely sealed, but rather to be a selective barrier made up of tightly connected cells that absorb key nutrients while restricting the passage of anything harmful. “Think of your gut lining like a coffee filter,” says Dr. Ilan Shapiro, medical director of health and wellness education and physician at AltaMed Health Services in California. “When it works well, it lets the good stuff through and keeps everything else from getting in,” he says, “but when it gets too porous, things that shouldn’t get through.” When this happens, increased permeability can occur, leading to “conditions such as celiac disease and inflammatory bowel disease (IBS),” says Nagata.
This increased permeability is often referred to on social media as “leaky gut” and is believed to be the cause of “reported symptoms such as bloating, gas, food sensitivities, joint pain, skin breakouts like eczema, and abdominal discomfort such as diarrhea, constipation, gas, or indigestion,” says Shapiro.
Despite such widespread references, the broader idea that increased intestinal permeability develops as its own syndrome and then causes problems throughout the body has not been established. A recent medical study concluded that “leaky gut syndrome” is not an accepted diagnosis because no validated blood, fecal, or other tests can reliably identify it.
It’s also worth noting that increased permeability itself may not cause any visible symptoms, says Shapiro. And even when symptoms do appear, they are often produced by something that actually irritates or injures the gut. “Many symptoms attributed to leaky gut appear in many other conditions and factors,” he adds. Consider constipation, lactose intolerance, infections and medication side effects.
What causes leaky gut?
When increased intestinal permeability occurs, it is thought to be caused by “any condition that inflames or damages the intestinal lining, including Crohn’s disease, ulcerative colitis, celiac disease, infections, and certain cancer treatments,” says Nagata.
Other factors that can affect gut health “include chronic, excessive alcohol consumption and a diet high in ultra-processed foods,” he says. Research has also documented an association between increased intestinal permeability and the use of nonsteroidal anti-inflammatory drugs, or NSAIDs, such as aspirin and ibuprofen, Nagata adds.
Shapiro says chronic stress can also worsen digestive symptoms and affect intestinal permeability via the gut-brain axis, because stress hormones and immune responses can influence digestion and connections between gut cells. “Poor sleep, repeated antibiotic use, environmental toxins, and even intense endurance exercise can also temporarily disrupt your gut lining,” he adds.
How is leaky gut treated?
While Shapiro notes that there are “no specifically FDA-approved treatments for ‘leaky gut'” because it is not a recognized medical condition, the best evidence-based approach for associated symptoms is for medical providers “to work to identify and treat the underlying problem,” Nagata says.
This means your doctor will review your symptoms, diet, and medications, and sometimes also order blood tests, stool tests, imaging, or endoscopy if necessary.
From there, treatment depends on the diagnosis.
Although persistent or worsening digestive symptoms should be evaluated by a healthcare professional, Nagata says the most significant measures to prevent digestive issues like intestinal permeability include “eating a balanced, high-fiber diet, limiting excess alcohol and ultra-processed foods, regular exercise, stress management, and getting enough sleep.”
Gn Health
