Beyond Bloating: Understanding Gut Health, Leaky Gut, and What Actually Helps

Leaky pipes = Leaky gut

Created by Christopher Caffrey, ACNP, PMHNP, Functional Medicine-Trained

May 21st, 2025 (Updated September 16th, 2026)

Key Takeaways:

Intestinal permeability is real, but “leaky gut” does not explain every symptom. Digestive problems, fatigue, and brain fog deserve evaluation for specific causes.

Zonulin tests and lectin claims need careful interpretation. Commercial zonulin testing has limitations, and properly prepared beans and grains do not need to be universally avoided.

Food, fiber, and daily habits form the foundation. Gradually introduced soluble fiber, such as Sunfiber, and tolerated fermented foods may help. Probiotic supplement benefits depend on the strain and condition.

Supplements should serve a specific purpose. Glutamine has promising evidence for selected postinfectious IBS cases. Colostrum and zinc carnosine have narrower evidence; magnesium can help constipation, while omega-3s support nutritional needs.

Xifaxan belongs in a targeted treatment plan. It can help IBS with diarrhea and selected SIBO cases, but it is not a general treatment for intestinal permeability.

During my years in gastroenterology, patients often came in because of bloating, constipation, diarrhea, or reflux. As we talked, other concerns emerged: poor sleep, fatigue, difficulty concentrating, anxiety, or a sense that something was off.

Working in psychiatry brought the connection into focus from another direction. Someone seeking help for mood or anxiety might also describe unpredictable digestion or discomfort after meals. These concerns deserved to be considered together, without assuming that one necessarily caused the other.

Imagine a fictional patient named Rachel. Her stomach has become unpredictable since a gastrointestinal infection. She has started skipping meals before meetings, avoiding foods she once enjoyed, and worrying about finding a bathroom. Her sleep and concentration suffer. Online, she finds an explanation that seems to connect everything: “leaky gut.”

There is real biology behind intestinal permeability. There is also a great deal of marketing built around it. Understanding the difference helps us move toward a plan that addresses the person and the actual problem.

What “Leaky Gut” Really Means

Your intestinal barrier includes mucus, epithelial cells, immune defenses, and the connections between neighboring cells, called tight junctions. It allows controlled exchange while limiting exposure to potentially harmful material. Increased intestinal permeability means that aspects of this barrier allow more passage than expected. It is not usually a matter of visible holes or whole pieces of food entering the bloodstream. [1]

Altered permeability occurs in conditions such as celiac disease, inflammatory bowel disease, and some forms of IBS. Depending on the condition, it may contribute to inflammation, result from inflammation, or both. It is a biological finding, not a diagnosis that explains every combination of fatigue, skin symptoms, anxiety, and digestive discomfort. [1]

For Rachel, the first question is what is driving her symptoms. Labeling them “leaky gut” would not distinguish postinfectious IBS from celiac disease, ongoing infection, or another treatable condition.

Start With the Pattern and Choose Tests Carefully

A useful assessment considers symptom timing, stool consistency, food intake, medications, infection history, sleep, and stress. Blood in the stool, unexplained weight loss, anemia, or persistent nighttime diarrhea deserve prompt evaluation. Testing should answer a question that changes care. Depending on the presentation, that may include celiac testing, targeted stool testing, or fecal calprotectin to assess for intestinal inflammation. Calprotectin does not directly measure permeability. IBS can be diagnosed using an appropriate symptom pattern and evaluation without ordering every available test. [2]

Commercial microbiome panels can produce detailed reports, but detail alone does not establish a validated diagnosis or treatment plan. Normal results also do not make symptoms imaginary. Functional medicine is most useful when it connects the history and evidence to practical decisions, rather than treating every flagged laboratory value.

Zonulin: Interesting Biology, Imperfect Testing

Zonulin is involved in regulating tight junctions. Experiments using intestinal tissue and cell models have shown that gliadin, a component of gluten, can influence zonulin release and permeability. These findings are relevant to understanding celiac biology, but they do not prove that eating gluten causes clinically harmful intestinal leakage in everyone. [3]

Measurement is another problem. Researchers found that a widely used commercial zonulin assay did not specifically detect the protein it was intended to measure. A reported “high zonulin” result therefore should not be treated as definitive proof of a damaged intestinal barrier. [4]

If celiac disease is suspected, discuss testing before eliminating gluten, because dietary removal can make diagnostic testing less reliable. A gluten-free diet is essential for confirmed celiac disease; universal gluten avoidance is a different claim.

Lectins: Preparation Matters More Than Fear

Lectins are carbohydrate-binding proteins found in many foods. Some can cause harm when consumed in sufficient amounts. Raw or inadequately cooked kidney beans, for example, contain a lectin that can cause severe vomiting and diarrhea. Proper cooking greatly reduces this risk, and canned kidney beans are already cooked. [5]

Laboratory findings involving concentrated lectins do not establish that ordinary servings of properly prepared beans, whole grains, or vegetables damage everyone’s gut. Eliminating these foods can also remove useful fiber and dietary variety.

When a food causes symptoms, consider the portion, preparation, fermentable carbohydrates, and individual tolerance. Bloating after beans does not by itself prove lectin injury. The aim is a varied diet you can tolerate, with restrictions used purposefully rather than indefinitely.

Build the Foundation With Food and Fiber

I would begin Rachel’s plan by restoring regular meals and adequate nutrition, while identifying manageable triggers. A short, structured low-FODMAP trial can help selected people with IBS, followed by reintroduction. It is a symptom-management tool rather than proof that restricted foods are harmful. [2]

Soluble fiber can be useful, but type and pace matter. Sunfiber is a branded form of partially hydrolyzed guar gum, or PHGG. A randomized trial using 6 grams daily found improvement in bloating and gas compared with placebo. This supports a targeted trial, not a guarantee of gut-barrier repair. [6]

Start with a small amount and increase gradually according to tolerance. Adding a large fiber dose to an already uncomfortable gut can backfire. Psyllium is another option with evidence for IBS and constipation. The right choice depends on the stool pattern, symptoms, and response.

Probiotic Foods and Supplements

Yogurt with live cultures, kefir, and fermented vegetables can add variety when tolerated. Not every fermented food contains live organisms, and not every live-culture food meets the scientific definition of a probiotic with demonstrated health benefits.

In a small randomized dietary study in healthy adults, a fermented-food diet increased microbial diversity and reduced several inflammatory markers. That supports further interest, but it did not demonstrate treatment of IBS or “leaky gut.” [7]

Probiotic supplements require more specificity. Effects depend on the strain, formulation, and condition. More strains or a higher CFU count does not automatically mean better results. Evidence for IBS is inconsistent enough that the American Gastroenterological Association recommends probiotics for IBS only within clinical trials. [8]

If a clinician recommends an individualized trial, define the goal and reassess. Persistent worsening is a reason to reconsider, not evidence that the product is “working.” People who are severely immunocompromised or critically ill need particular caution with live microbial supplements.

L-Glutamine: A Promising Targeted Option

Glutamine is an amino acid used by intestinal cells. A randomized trial in people with postinfectious, diarrhea-predominant IBS and increased permeability found that 5 grams three times daily for eight weeks improved symptoms and permeability measurements compared with placebo. [9]

This is meaningful human evidence for a selected group resembling one possible explanation for Rachel’s symptoms. It does not establish the same benefit for constipation, every form of IBS, or unexplained fatigue. The research dose is an example for clinical discussion, not a universal protocol.

For an appropriate patient, a monitored trial may be reasonable after assessment. Improvement should be judged by function and symptoms as well as any clinically useful measurements.

Colostrum: Potential Support, With Limits

Bovine colostrum contains immunoglobulins, growth factors, and other proteins that have prompted research into intestinal protection. Small human studies have reported reduced exercise-associated increases in permeability. However, studies have varied in their findings and methods, and much of the evidence involves athletes or exercise stress. [10, 11]

Colostrum may be considered as an adjunct in selected circumstances, but describing it as a patch that seals everyone’s gut overstates what we know. Product quality and processing matter. Avoid it with cow’s-milk protein allergy, and remember that milk allergy differs from lactose intolerance. It should not replace treatment of a diagnosed digestive disease.

Magnesium, Zinc, and Omega-3s Have Different Jobs

Magnesium can help constipation by drawing water into the bowel. Magnesium oxide has conditional support in constipation guidelines; magnesium glycinate should not be assumed to have the same laxative evidence. Excess can cause diarrhea, and impaired kidney function increases the risk of magnesium accumulation. This is bowel management, not demonstrated barrier repair. [12]

Zinc supports normal tissue and immune function, and correcting deficiency matters. A small crossover study in ten healthy volunteers found that zinc carnosine reduced the permeability increase caused by indomethacin. This is a promising, narrow finding, supported by laboratory work, rather than proof of a universal gut-healing effect. [13] Count elemental zinc across products: prolonged excessive intake can cause copper deficiency. The adult upper intake level is 40 mg daily unless treatment is medically supervised. [14]

Omega-3s, including EPA and DHA, contribute to cell membranes and inflammatory signaling. Food sources such as salmon and sardines can support nutritional adequacy, and supplements may suit particular needs. They are not established treatments for IBS or generalized intestinal permeability. High-dose use warrants medication review, including bleeding considerations and the atrial-fibrillation signal seen in some cardiovascular trials. [15]

Where Xifaxan Fits

Xifaxan, or rifaximin, is an antibiotic that acts primarily within the intestine. In the United States, it is approved for adults with IBS with diarrhea. The labeled regimen is 550 mg three times daily for 14 days, with up to two repeat courses for recurrence when appropriate. It can help some patients, but it is not a general treatment for “leaky gut.” [16]

Rifaximin is also used off-label for selected cases of small intestinal bacterial overgrowth, or SIBO. Bloating alone does not diagnose SIBO. Breath testing can help in appropriate circumstances, but results require careful interpretation. Methane-associated constipation, termed intestinal methanogen overgrowth, is a distinct consideration and may require a different strategy. [17]

Medication should be paired with attention to contributors such as impaired motility. Repeated antibiotics without reassessment can miss the underlying problem. Rifaximin has risks, including hypersensitivity and antibiotic-associated diarrhea, so its use should follow a clinical indication. [16]

Recovery Should Make Life Bigger

For Rachel, progress might mean eating before a meeting without fear, fewer urgent bathroom trips, and a diet that gradually becomes more varied. Those outcomes matter more than accumulating supplements or chasing a perfect microbiome report.

Regular sleep, appropriate movement, stress management, and gut-directed psychological therapies can belong alongside nutrition and medical treatment. Addressing the gut–brain relationship does not suggest symptoms are imagined. It acknowledges that digestive function and nervous-system responses interact. [2]

At Flexup Wellness, my approach is to understand the pattern, identify treatable contributors, choose a manageable starting plan, and reassess. Glutamine, colostrum, fiber, probiotics, nutrients, and prescriptions each have possible roles. They do not all belong in every plan. The goal is better digestion, better function, and more confidence in everyday life.

This article is educational and does not replace individualized medical advice. Discuss supplements, testing, and prescription treatment with your clinician.

References

[1] Camilleri M. Leaky gut: Mechanisms, measurement and clinical implications in humans. Gut. 2019;68:1516–1526.

[2] Lacy BE, et al. ACG Clinical Guideline: Management of Irritable Bowel Syndrome. American Journal of Gastroenterology. 2021;116:17–44.

[3] Drago S, et al. Gliadin, zonulin and gut permeability: Effects on celiac and non-celiac intestinal mucosa and intestinal cell lines. Scandinavian Journal of Gastroenterology. 2006;41:408–419. Human tissue and cell experiments.

[4] Scheffler L, et al. Widely used commercial ELISA does not detect precursor of haptoglobin2, but recognizes properdin as a potential second member of the zonulin family. Frontiers in Endocrinology. 2018;9:22.

[5] U.S. Food and Drug Administration. Natural Toxins in Food.

[6] Niv E, et al. Randomized clinical study: Partially hydrolyzed guar gum versus placebo in patients with irritable bowel syndrome. Nutrition & Metabolism. 2016;13:10.

[7] Wastyk HC, et al. Gut-microbiota-targeted diets modulate human immune status. Cell. 2021;184:4137–4153.e14.

[8] Su GL, et al. AGA Clinical Practice Guidelines on the Role of Probiotics in the Management of Gastrointestinal Disorders. Gastroenterology. 2020;159:697–705.

[9] Zhou Q, et al. Randomised placebo-controlled trial of dietary glutamine supplements for postinfectious irritable bowel syndrome. Gut. 2019;68:996–1002.

[10] Marchbank T, et al. The nutriceutical bovine colostrum truncates the increase in gut permeability caused by heavy exercise in athletes. American Journal of Physiology–Gastrointestinal and Liver Physiology. 2011;300–G484.

[11] Dziewiecka H, et al. A systematic review of the influence of bovine colostrum supplementation on leaky gut syndrome in athletes. Nutrients. 2022. Exercise-related studies; findings do not establish routine IBS treatment.

[12] Chang L, et al. AGA–ACG Clinical Practice Guideline: Pharmacological Management of Chronic Idiopathic Constipation. Gastroenterology. 2023;164:1086–1106.

[13] Mahmood A, et al. Zinc carnosine, a health food supplement that stabilises small bowel integrity and stimulates gut repair processes. Gut. 2007;56:168–175. Laboratory studies and a small human crossover trial.

[14] NIH Office of Dietary Supplements. Zinc: Health Professional Fact Sheet.

[15] NIH Office of Dietary Supplements. Omega-3 Fatty Acids: Health Professional Fact Sheet.

[16] Salix Pharmaceuticals. Xifaxan (rifaximin): U.S. Prescribing Information.

[17] Pimentel M, et al. ACG Clinical Guideline: Small Intestinal Bacterial Overgrowth. American Journal of Gastroenterology. 2020;115:165–178.