Leaky Gut Test At Home

Why Should You Care About Leaky Gut?

A healthy gut has a balanced microbiota and a healthy barrier between you and your external environment, including your gut content. Although a leaky gut gets a bad rap, it’s a completely natural process that can happen and reverse itself. Studies show the gut barrier becomes more permeable or leaky when:

• You’re physically or emotionally stressed such as a hard workout or an exam
• Eat certain common foods like gluten or a high-fat, high-sugar, high-salt meal

In an optimally healthy person, your gut should be able to reseal itself after each of these instances. However, when these root causes are ongoing or when you have increased suboptimal microbes in your gut, the leaky gut can be perpetual.

When you have a leaky gut, the gut content such as bacteria parts and half-digested food can be exposed to your immune system. It can lead to a low-grade immune system activation or sensitization. It’s not perfectly optimal, but it’s not a disease on its own. 

Curious if you have a leaky gut? In this article, we will cover how it’s typically diagnosed and objective tests that can confirm it. 

For a deeper dive into leaky gut, check out our articles on how to repair leaky gut and leaky gut and weight gain. 

How Is Leaky Gut Diagnosed?

Naturopathic or integrative doctors typically diagnose it through symptoms such as bloating, suboptimal digestion, skin concerns, and joint discomfort. However, some people don’t have many symptoms or can’t accurately gauge their feelings or progress without using objective tests. 

Although there is no universally accepted test for leaky gut, some at-home tests can assist in diagnosing and understanding gut health and permeability with objective measurements. 

Objective Tests for Leaky Gut From Home

The following list of tests can be administered or analyzed from home. This article is here to guide you through your decision of which test to take and the pros and cons of each. 

1. Lactulose/Mannitol Test

Lactulose/mannitol testing is the most common method for diagnosing leaky gut by measuring intestinal permeability.

This test involves consuming a solution containing two sugars with different molecular sizes: lactulose and mannitol—specifically, 5 g of lactulose and 2 g of mannitol in 100 mL of water. Lactulose is a larger molecule (disaccharide) that is not generally absorbed into the small intestine, whereas mannitol (monosaccharide) is a smaller molecule that is easily absorbed through villi .

Typically, this test can be prescribed by a licensed provider. Patients with diabetes, high glucose levels, medications that may alter blood glucose, and allergic reactions to sorbitol, xylitol, and lactulose should avoid this test. Medications such as NSAIDs, aspirin, and antacids should be avoided three days before administration

The sugar solution should be consumed after an overnight fast, and no food or drink other than water should be consumed until 2 hours after completion. Avoid foods containing fructose, lactose, mannitol, or other sugar alcohols until completion. Typically, the urine is collected 5-6 hours after consuming the sugar solution

This test measures intestinal permeability by calculating the ratio of lactulose and mannitol (LMR) recovered in the urine within a specific time frame. An elevated ratio is an indicator of dysfunctional intestinal permeability

Every clinic has its cut-off values, but typically, in a healthy adult, the percentage excretion of lactulose and mannitol should range from 0.0204-1.8030 and 1.4800-43.7500, respectively, with a median LMR value between 0.0029-0.02510.

This test may help identify the difference between Crohn’s and celiac disease. Since mannitol is readily absorbed through the small intestine’s villi and Crohn’s does not cause villous atrophy, the urine levels should not be affected in this condition. In comparison, due to villous atrophy in celiac disease, the amount of mannitol excreted will be significantly affected. However, with villous atrophy in mind, many inflammatory conditions may vary results significantly and alter the sensitivity and specificity of the results.

Overall, this is a simple, noninvasive, and popular at-home test, but more standardization may provide reliable results. 

	Pros	Cons
Lactulose/Mannitol Test	– Sensitive and specific testing when testing the same patient -Most common at-home test -Simple and non-invasive -Same day testing -Can provide a snapshot into the progress of the healing protocol	-The lactulose-mannitol solution may cause diarrhea -The purchase of lactulose requires a prescription -Requires handling urine and a long list of instructions -Time consuming (5-6 hours)It lacks standardization due to population and collection time variations, and every lab has its cut-off values -Certain medications and conditions can alter the resultsIt should be avoided in patients with diabetes, high glucose levels, and allergic reactions to sorbitol, xylitol, and lactulose -A long list of foods to avoid and fasting

2. Zonulin 

Zonulin blood and stool testing measures zonulin levels and related proteins that regulate intestinal permeability through tight junctions. Tight junctions are intercellular barriers between epithelial cells that regulate the permeability of substances from the digestive tract to the bloodstream. Zonulin controls permeability by decreasing the stability of tight junctions. Thus, when elevated, it can be helpful as a biomarker for leaky gut

The Zonulin blood test measures zonulin and other peptides related to intestinal permeability, called zonulin family peptides. Zonulin measures the integrity of the gut barrier, and abnormal values can indicate conditions such as celiac and autoimmune diseases. However, high zonulin alone is not diagnostic of any disease.

We need more evidence regarding whether zonulin is a good biomarker for intestinal permeability. There is a correlation between lactulose and mannitol ratios and fecal zonulin testing in overweight and obese patients However, the evidence is weak that this test is a specific, reliable marker for any disease. Zonulin is also not a good indicator of gut diseases.

Commercially available blood test kits are unreliable for measuring zonulin as a permeability marker. The zonulin ELISA stool test has greater specificity as it includes other family protein markers, making it a more reliable test for leaky gut Patients with conditions involving the gastrointestinal tract may benefit from adding zonulin testing to their additional stool and blood work. 

The Zonulin blood test ranges from 25.1 to 160.8ng/mL and the fecal zonulin normal range is under 30 ng/mL . Elevated levels may be associated with conditions such as celiac disease or non-celiac gluten sensitivity. However, it is not diagnostic of celiac disease as many non-celiacs have elevated zonulin.

	Pros	Cons
Zonulin	-Correlation with lactulose and mannitol testing in overweight and obese populations -ELISA blood sample tests multiple protein markers of intestinal permeability -The blood test is easy to do -Commercially available at-home test  -No side effects	-Expensive testing -Handling stool -List of instructions  -Typically prescribed by a licensed provider for blood and stool test -Unreliable as a biomarker for intestinal permeability  -Commercially available tests are unreliable as they may not measure specific zonulin levels

3. Blood LPS and LPS Antibody Levels

LPS, or lipopolysaccharides, are large molecules found on the surface of Gram-negative bacteria. Large amounts of LPS can cause sepsis. However, small amounts of LPS, typically from your normal gut bacteria, can indicate leaky gut. When LPS is present, the gut microbiota and GALT (gut-associated lymphoid tissue) shift towards an inflammatory response. 

Increased blood LPS can contribute to inflammation, weight gain, and suboptimal blood sugar regulation, and other metabolic issues. In obese people, LPS can change the adipose tissue function, increasing the inflammatory response. Overall, more LPS can tip the metabolism towards more weight gain.

Another test that can measure LPS is blood LPS antibodies (IgG). This measurement ranges from 0 to 2.6 on the ELISA index. When LPS antibodies are present in the body, this signifies an inflammatory response, specifically in the gut microbiota. Although LPS antibody is a general marker for inflammation, it is not typically prescribed to diagnose leaky gut. 

In addition to LPS antibodies, there is a blood test called LBP that measures the binding proteins of LPS. The reference range in healthy adults is 1.85 to 17.4 mg/L. LBP may be a valuable marker for assessing the permeability of intestines in adults, independent of age, BMI, and sex. However, bacterial infections may increase circulating LBP, making this unsuitable in patients with bacterial infections. Results are somewhat inconsistent using this measure.

	Pros	Cons
Blood LPS Levels	-Easy blood test. It gives a snapshot of the body’s inflammation levels  -No side effects  -No handling of urine, saliva, or poop	-Not specific or sensitive for gut inflammation and leaky gut diagnosis  -Requires a requisition from a doctor -Doesn’t narrow down where or what the infection is -Can’t use this measure when a patient has a bacterial infection

4. sIgA 

Secretory IgA (sIgA) is the most abundant antibody in the body, typically found on mucus membranes. SIgA is crucial in defending the intestinal barrier from pathogen adhesion and intrusion. SIgA promotes the clearance of pathogenic microorganisms in the intestinal lumen by entrapping them in mucus and facilitating bodily removal.

People with a lower IgA serum level have an increased risk for infections of the mucosal surface, such as food allergies and celiac or other autoimmune responses. Whereas, a high sIgA may indicate an ongoing factor that stimulates the immune response.

sIgA typically protects the gut lining. We also see dysbiosis and leaky gut symptoms when there is a deficiency. Without this defense mechanism, tight junctions of the epithelium are impaired. Many celiacs have low sIgA, but others can also have low sIgA. When sIgA levels are high this can indicate an infection of the GI tract as there is less epithelial barrier to microbes. 

Fecal SIgA is a marker in common stool test panels, which is regularly prescribed in suspected leaky gut patients. Salivary SIgA provides a whole-body overview of SIgA in the body.

Serum IgA optimal results: 426-1450 mcg/g  

Fecal SIgA  – 510-2010mcg/g

	Pros	Cons
sIgA	-No side effects. It can be tested through blood, saliva, or stool  -Test from the comfort of home -Included in other stool tests such as GI-MAP	-It is not specific to the gut’s mucosal lining, as IgA is related to all mucosal tissue -Doesn’t typically correlate with how a patient feels -Varies greatly depending on gender, age, health history, and method of testing -Typically, it requires a prescription from a licensed provider  -Stool or saliva testing are not convenient

Tests for Leaky Gut in the Doctor’s Office

Confocal Endomicroscopy

Confocal laser endomicroscopy (CLE) is an endoscopic procedure that obtains a high magnification and resolution image of the GI tract mucosal layer. Confocal imaging can use tissue reflectance or fluorescence. Tissue reflectance doesn’t require a contrast agent, but CLE using fluorescent agents generates a clearer image. The fluorescent agent can be administered intravenously or topically. 

The images measure duodenal permeability, which helps examine a leaky gut. This endoscopic procedure can diagnose Barrett’s esophagus, biliary strictures, polyps, and IBD. Through these high-resolution images, we can understand the health and permeability of the mucosal layer of the GI tract.

Conclusion:

Many tests can provide insight into the gut microbiome and permeability of the gut lining. The takeaway from this overview is that every test has pros and cons. If you are considering investigating, you should consult your naturopathic or functional medicine doctor to determine which one is best for you. 

Check out additional articles on leaky gut: 

How to Repair Leaky Gut

Leaky Gut and Weight Gain