Leaky Gut: How Do You Know If You Have It?

By · Clinical Director · · 8 min read

Is leaky gut real?

Leaky gut is real as a process, but no symptom or home test can tell you on its own that you have it. You find out by ruling out the conditions that cause it.[2]

Your gut lining is a single layer of cells held together by tight seals. The seals let water and nutrients through and keep most bacteria and food particles out. Everyone’s gut lets a little through, and that’s normal. When the seals loosen, more gets through. Doctors call this increased intestinal permeability, and it can be measured in a lab.

Leaky gut syndrome is the claim that a leaky gut causes a long list of symptoms, from bloating to brain fog. It isn’t an accepted medical diagnosis. In a 2024 review, Mayo Clinic gastroenterologists found raised permeability linked to only a few conditions, including IBS, inflammatory bowel disease and type 1 diabetes. For chronic fatigue, headaches, allergies and brain fog, they found no reliable evidence that a leaky gut plays a part.[2]

So, is it all in your head? No, your symptoms are real, and they have a cause. It may not be a leaky gut.

Leaky gut symptoms, and what else they can point to

Bloating, gas, belly pain, diarrhea, constipation, tiredness, food reactions, headaches and brain fog all get blamed on a leaky gut. Almost every one has a more common cause, so the list can’t tell you what’s going on.

What you notice

What else commonly causes it

What can check it

Bloating, gas

IBS, an overgrowth of gut bacteria called SIBO, or trouble digesting lactose

A hydrogen breath test

Diarrhea, constipation or both

IBS, celiac disease, Crohn’s disease, ulcerative colitis or an infection

A celiac blood test and a stool test like calprotectin for gut inflammation

Reactions to bread, pasta or milk

Celiac disease or lactose intolerance

A celiac blood test while you’re still eating gluten, and a hydrogen breath test

Tiredness

Anemia, among many other causes like malabsorption syndrome

A blood count

Brain fog, headaches, aches or skin flares

Many causes, and no reliable evidence that a leaky gut is one

Your doctor, one symptom at a time

Food sensitivities, allergies, or intolerances.

Genetic predisposition, immune-system reactions

Skin-prick test or blood-specific IgE testing

For women, IBS deserves a closer look first. Nearly 1 in 20 adults in the US has IBS, and it’s more common in women.[3]

What causes a leaky gut?

Raised gut permeability has known causes, and you can change several of them. Gut infections, antibiotics and other medicines, alcohol, stress and hard endurance exercise can all loosen the seals, and so can inflammatory bowel disease.[2]

Two of these have been tested on healthy people. In a 2014 study in the journal Gut, 23 volunteers took a urine sugar test after different challenges. Their guts became more permeable after a dose of indomethacin, a painkiller in the same family as ibuprofen and naproxen. The same happened after they gave a public speech, but only in those whose cortisol rose.[4]

Long-term stress is also linked to IBS, reflux and indigestion, through the constant signaling between your gut and your brain. Our blog on the gut-brain connection explains how.

What about the “three foods that cause leaky gut”? People search for that list, and there isn’t one. Alcohol and some food additives called emulsifiers raise permeability in studies. Gluten is a different case. In celiac disease, the immune system reacts to gluten and damages the small intestine, and a blood test can find that out.

Ayurvedic Science groups loose stools, bloating and poor absorption under grahani, a chronic digestive disorder marked by poor nutrient absorption, and traces it to weak agni, your body’s digestive fire. Weak agni leaves food half-digested as ama, harmful residue from incomplete digestion. Modern research and Ayurvedic Science start with the same step, which is to find the cause and remove it. Our guide to agni and ama explains more.

Can a test tell you if you have a leaky gut?

Not yet. No blood, stool or urine test is validated to diagnose leaky gut, and a standard colonoscopy can’t see it either.

Then what about the zonulin tests sold online as leaky gut tests, you may ask? Zonulin is a protein that loosens the seals between gut cells, so a high reading sounds like proof. But, in a 2019 study in PLOS One, researchers in Australia checked two widely used zonulin blood-test kits and found they were detecting other proteins and not zonulin.[5]

Mayo Clinic reviewers call the value of over-the-counter zonulin kits “suspect,” and stool tests for leaky gut unregulated.[1]

A “leaky gut test” kit ranges from $59 to $599. Before you buy one, ask what you’d do with the result. If the answer is “take it to my doctor,” start there.

What can you do about leaky gut symptoms now?

Start with the causes you can change. If you take an anti-inflammatory painkiller most days, talk to your doctor about it, and don’t stop a prescribed medicine on your own. Drink less alcohol. Don’t leave stress out of it, because acute stress can make your gut more permeable.

Eat more fiber. Gut bacteria turn fiber into compounds that may help hold the seals together, though no study has tested fiber as a fix for leaky gut.

One easy thing you can start tonight is a two-week diary. Note what you eat and when, your stools, your sleep, your stress and any painkillers you take. It turns “I’m always bloated” into a pattern your doctor can work with.

How LYBL supports your gut when the tests come back normal

If your tests come back normal and the bloating stays, you’re left with a symptom and no plan. Standard tests are built to find disease, and they do that well. They don’t look at when you eat, how you sleep, what you’re under or which medicines you take, and any of those can keep a sensitive gut flaring.

Our Digestive and Gut Health program helps find the pattern behind your symptoms. It starts with the health assessment, then a free consultation of up to 60 minutes if needed with a Holistic Health Physician. Your physician looks at your bowel pattern, what and when you eat, stress levels, sleep and medications, and your symptom history. Your food plan is built to strengthen agni and clear ama. It starts with an elimination diet that takes out the foods you react to. If you haven’t had a celiac blood test, get it before gluten comes out.

Your plan can also include targeted formulations and yoga therapy. Gut Absorption Support is formulated to support a healthy gut and digestive function.* It’s a blend of herbs and spices that includes pomegranate, cumin and pepper. Our yoga therapists build a routine to relieve stress, as high levels can make your gut more permeable.

A routine does the most good when it's aimed at the right problem.

Frequently asked questions

Can a colonoscopy detect a leaky gut?

No. A colonoscopy can’t measure how permeable your gut is. It can find Crohn’s disease, ulcerative colitis and colon cancer, which is why your doctor may still order one.

Is leaky gut the same as SIBO or IBS?

No. SIBO is an overgrowth of bacteria in the small intestine, and a breath test can check for it. IBS is belly pain with changes in your bowel movements, and it’s one of the few conditions linked to raised gut permeability.

Is there a link between leaky gut and anxiety?

Stress affects the gut through constant signaling between gut and brain. In healthy volunteers, giving a public speech made the gut more permeable in those whose cortisol rose. Whether stress causes long-term gut problems this way is still unproven.

Is leaky gut linked to autoimmune disease?

Raised gut permeability is linked to a few immune-related conditions, including type 1 diabetes and inflammatory bowel disease. No study has shown that a leaky gut causes them.

What are the signs your gut is improving?

Fewer bloated days, more regular stools and less urgency usually come first. A reduction in food sensitivities, allergies, or intolerances are also useful indicators. No home test tracks your gut lining, so compare two weeks of a symptom diary now with two weeks a couple of months from now.

References

  1. Lacy BE, Wise JL, Cangemi DJ. Leaky gut syndrome: myths and management. Gastroenterol Hepatol (N Y). 2024;20(5):264-272. View original source ↩
  2. Camilleri M. Leaky gut: mechanisms, measurement and clinical implications in humans. Gut. 2019;68(8):1516-1526. View original source 123
  3. Palsson OS, Whitehead W, Törnblom H, Sperber AD, Simren M. Prevalence of Rome IV functional bowel disorders among adults in the United States, Canada, and the United Kingdom. Gastroenterology. 2020;158(5):1262-1273.e3 View original source ↩
  4. Vanuytsel T, van Wanrooy S, Vanheel H, et al. Psychological stress and corticotropin-releasing hormone increase intestinal permeability in humans by a mast cell-dependent mechanism. Gut. 2014;63(8):1293-1299. View original source ↩
  5. Ajamian M, Steer D, Rosella G, Gibson PR. Serum zonulin as a marker of intestinal mucosal barrier function: may not be what it seems. PLoS One. 2019;14(1):e0210728. View original source ↩