Leaky Gut Syndrome: Symptoms, Diagnosis and How to Heal It
Leaky gut, also known as increased intestinal permeability, is a condition gaining recognition in both conventional and functional medicine. For decades, we’ve known the gut plays a central role in health, but only recently have we begun to understand just how deeply it influences digestion, immunity, mental health, and chronic disease risk.
This guide explores what leaky gut is, the most common symptoms, how it is diagnosed, and the integrative therapies I use in practice, including functional medicine lab testing and targeted dietary strategies.
What is Leaky Gut?
Your intestines are lined with a single layer of specialized cells that form a protective barrier between your digestive tract and the rest of your body. These cells are connected by tight junction proteins, which work like a well-fitted zipper. Their job is to let in the nutrients you need while blocking harmful substances from entering your bloodstream.
When these tight junctions become weakened or damaged, unwanted particles like undigested food, toxins, or harmful bacteria can “leak” into the bloodstream. This process is called intestinal hyperpermeability, but it’s more commonly referred to as leaky gut.
Understanding and tackling this can be a key to helping with many bigger health problems. This is because the things getting through the gut wall, like pieces of undigested food or harmful bacteria, can find their way into our bloodstream and trigger an immune response.
Divella, R., Palma, G. D., Tufaro, A., Pelagio, G., Gadaleta-Caldarola, G., Bringiotti, R., … & Paradiso, A. (2021). Diet, probiotics and physical activity: the right allies for a healthy microbiota. Anticancer Research, 41(6), 2759-2772. https://doi.org/10.21873/anticanres.15057
What Causes Leaky Gut?
It's not just one factor that can lead to this condition; a multitude of medical and lifestyle factors play a role. From the natural aging process to specific diseases and treatments, here's a comprehensive list of conditions and factors that have been linked to the onset of hyperpermeability:
Dysbiosis & Aging: As we age, our bodily functions, including those in our gut, can decline and the bacterial composition of our guts also changes. The intestinal walls can become weaker, making them more susceptible to permeability issues.
Alcohol: Excessive alcohol intake can damage the gut lining, increasing its permeability and causing harmful substances to enter the bloodstream.
Malnutrition: Lack of essential nutrients can weaken the gut lining, making it more susceptible to damage and increased permeability.
NSAIDs: Nonsteroidal anti-inflammatory drugs can irritate and harm the gut lining, leading to increased permeability.
Food Sensitivities: The most common food sensitivities that can lead to leaky gut are gluten and dairy. However, any food that causes an immune reaction can lead to local inflammation that over time can damage the lining of your intestines.
Gut Pathogens & Parasites: Intestinal parasites, like Giardia, can cause inflammation and directly damage the gut lining. There are many other viruses and bacterial pathogens that can take up residence in your intestines. Their presence can disrupt the balance of beneficial bacteria in the gut, making the intestines more susceptible to permeability issues.
Pancreatic Insufficiency/Pancreatitis: The pancreas secretes enzymes that aid in the proper breakdown of large food particles into smaller protein complexes. When there is an issue with pancreatic function, food isn’t broken down correctly and the presence of these larger food protein complexes leads to inflammation, immune activation, and the subsequent breakdown of the intestinal barrier.
Ulcerative colitis: This is a chronic inflammatory bowel disease that causes ulcers in the colon and rectum. These ulcers can damage the lining of the colon, leading to increased permeability. The ongoing inflammation associated with ulcerative colitis further exacerbates the issue.
Rheumatoid arthritis: This autoimmune disease involves the immune system attacking the body's own tissues. The inflammatory response associated with rheumatoid arthritis can potentially disrupt the balance and health of the gut, contributing to hyperpermeability.
Chronic hepatitis: Chronic inflammation of the liver can lead to a disruption in bile production and other digestive processes, potentially affecting the health and integrity of the intestinal wall.
Celiac disease: This autoimmune disorder targets the gut lining in response to gluten, leading to damage and increased permeability.
Certain drugs: Beyond NSAIDs, other medications can affect the balance of good and bad bacteria in the gut or irritate its lining, potentially leading to hyperpermeability.
Crohn's disease: This chronic inflammatory bowel disease directly targets the lining of the digestive tract, causing ulcers, inflammation, and damage that can significantly increase intestinal permeability.
Cystic fibrosis: This genetic disorder affects the mucus-producing cells in the body, leading to thicker, stickier mucus. This can disrupt the balance of beneficial bacteria in the intestines and impair digestion, potentially making the gut lining more vulnerable to increased permeability.
Cancer: Some cancers can directly affect the intestines or create an inflammatory response that may compromise the gut lining.
Radiation therapy: Used to treat cancer, radiation can cause inflammation or direct damage to the intestines, which can lead to increased permeability.
Chemotherapy: Used to combat cancer cells, chemotherapy drugs can also affect the fast-dividing cells of the gut lining. This can weaken the intestinal barrier, leading to increased permeability.
Shock or anaphylaxis: Severe allergic reactions or shock can lead to a rapid inflammatory response throughout the body, which may include the gut. This sudden reaction can disrupt the intestinal barrier, leading to increased permeability.
Trauma: Physical injury, especially abdominal trauma, can directly damage the intestines. Additionally, the stress response from trauma can lead to inflammation, potentially impacting the health of the gut lining and leading to hyperpermeability.
Symptoms of Leaky Gut
The symptoms of leaky gut can be diverse and sometimes non-specific. From stomach upsets to mood swings, leaky gut highlights how deeply our gut health can influence our overall well-being. Here's a breakdown of some of the most common symptoms associated with this condition:
Digestive issues: bloating, gas, diarrhea, or irritable bowel syndrome (IBS).
Skin issues like acne, rosacea, or eczema.
Fatigue and difficulty concentrating.
Frequent infections and compromised immunity.
Joint pain or rheumatoid arthritis.
Mood imbalances, including anxiety and depression.
Food allergies or intolerances.
Why Diagnosis Can Be Tricky
Leaky gut is not a single disease but an underlying problem that can contribute to many chronic conditions. It is often overlooked in traditional medical settings because its symptoms can mimic other digestive issues. Functional medicine practitioners tend to recognize the signs earlier and use both symptom history and targeted testing to make a diagnosis.
Lab Testing for Leaky Gut
While some people are diagnosed based on symptoms alone, functional lab testing can confirm leaky gut and help rule out other conditions such as Crohn’s disease, ulcerative colitis, or celiac disease.
One helpful blood marker is LPS (lipopolysaccharides). LPS is a component of the outer membrane of certain bacteria and can indicate leaky gut when found in the bloodstream.
Key functional tests may include:
Serum Tests: LPS, Anti-actomyosin, Zonulin & Occludin (I use Array 2 by Cyrex Laboratories)
Comprehensive Stool Analysis: GI effects (Genova), or GI MAP (Diagnostic Solutions)
The 4 R's approach:
One of the most effective functional medicine frameworks for restoring gut health is called The 4 R’s. This process is designed to remove irritants, restore proper digestion, repair the gut lining, and rebalance healthy gut bacteria. This is a framework that many integrative practitioners (myself included) use for healing and maintaining a healthy gastrointestinal (GI) system. Here's how it works:
Remove:
Eliminate added and refined sugars. Refined sugar fosters the growth of harmful bacteria and worsens gut health. Check out my article for a comprehensive look at sugar addiction and how to reset your relationship with it.
Eliminate foods and factors that damage the gut, such as inflammatory foods (like gluten and dairy for some individuals), infections, and irritants like alcohol and nonsteroidal anti-inflammatory drugs (NSAIDs).
2. Replace
Support healthy digestion by replenishing what the body may be missing.
Add digestive enzymes, hydrochloric acid (HCl), or bile salts if testing shows low digestive function.
Eat a variety of whole foods rich in natural enzymes, such as fresh fruits and fermented vegetables.
3. Repair
Provide targeted nutrients to help the gut lining rebuild and function properly.
Common supplements include L-glutamine, zinc carnosine, omega-3 fatty acids, and vitamins A, C, and E.
Herbal options like slippery elm, marshmallow root, and aloe vera can soothe irritation and support mucosal healing.
4. Rebalance
Restore healthy gut flora with probiotics and prebiotic-rich foods like garlic, onions, asparagus, and green bananas.
Focus on lifestyle choices that maintain gut health: reduce stress, get adequate sleep, and maintain a regular eating schedule.
Include fiber-rich foods daily to nourish beneficial bacteria.
Where to Start If You Suspect Leaky Gut
If you are experiencing symptoms like bloating, fatigue, skin flare-ups, or recurring infections, the best place to start is by:
Removing inflammatory foods
Adding nutrient-dense, whole-food meals
Considering functional lab testing to identify root causes
I offer a Free Gut Health Guidebook and a Gut Health Toolkit to help you take your first steps toward better digestion and whole-body health. These resources are designed to give you clarity and a clear action plan so you don’t feel overwhelmed.
Frequently Asked Questions About Leaky Gut
1: What is leaky gut?
Leaky gut, also called intestinal permeability, happens when the tight junctions in your intestinal lining become weakened or damaged, allowing unwanted substances to pass into the bloodstream.
2: What causes leaky gut?
Common triggers include poor diet, chronic stress, infections, certain medications like NSAIDs, alcohol use, and imbalances in gut bacteria.
3: What are common symptoms of leaky gut?
Digestive issues like bloating, gas, or diarrhea, skin conditions such as acne or eczema, fatigue, brain fog, joint pain, mood imbalances, and food sensitivities can all be linked to leaky gut.
4: How is leaky gut diagnosed?
Diagnosis is often based on symptoms and ruling out other conditions, but functional medicine testing may include serum markers like LPS, Anti-actomyosin, Zonulin, and Occludin, as well as comprehensive stool analysis.
5: Can leaky gut be healed?
Yes. Once IBD or other disease processes are ruled out, many people find relief through the 4 R’s approach: Remove irritants, Replace digestive support, Repair the gut lining, and Rebalance healthy gut bacteria.
6: How long does it take to heal leaky gut?
Healing timelines vary but oftentimes it takes a minimum of 6 weeks to notice symptom change and may take several months or more, depending on the severity of the damage, underlying causes, and how consistently treatment steps are followed.
Resources
Fink, Mitchell P. "Intestinal epithelial hyperpermeability: update on the pathogenesis of gut mucosal barrier dysfunction in critical illness." Current opinion in critical care 9.2 (2003): 143-151.
Bein, Amir, et al. "LPS induces hyper‐permeability of intestinal epithelial cells." Journal of Cellular Physiology 232.2 (2017): 381-390.
Liu, Z., N. Li, and J. Neu. "Tight junctions, leaky intestines, and pediatric diseases." Acta paediatrica 94.4 (2005): 386-393.
Farhadi, Ashkan, et al. "Intestinal barrier: an interface between health and disease." Journal of gastroenterology and hepatology 18.5 (2003): 479-497.
Medical Disclaimer: The content provided on this blog, including text, graphics, images, and other material, is for informational purposes only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment. The information on this blog is not intended to replace a one-on-one relationship with a qualified healthcare professional and is not intended as medical advice. Please consult your healthcare provider before making any changes to your health regimen.
