The epithelial layer of your gut plays an essential role in the digestion and absorption of nutrients, but it also serves as a barrier to prevent toxins and pathogens from passing from the lumen into the rest of the body. Disruption of gut barrier function from mucosal inflammation or tissue injury may lead to a loss of tight junction integrity and is possibly linked to numerous other gastrointestinal (GI) conditions. 

Unfortunately, poor gut barrier protection may be all too common in your patients. When developing a nutritional protocol, key nutrients can work in synergy to repair the tissues and relieve inflammatory burden to give the gut barrier lasting protection.


1. Tight Junctions, the Microbiome and Vitamin D

The gut barrier and the microbiome play key roles in training the immune system—over 70% of the immune system resides in the gut. For example, gut bacteria help your immune system’s T-cells develop by teaching them the difference between a foreign substance and the body’s own tissues. This vital process determines how and what your immune system responds to. Microbial imbalances in the gut can even lead your body’s immune system to turn on your own cells, which may produce an autoimmune condition.

Alongside immune system development, the gut barrier and the microbiome also work together to act as gatekeepers that regulate which particles pass through the gut lining into the rest of your body. Microbial imbalances combined with poor dietary intake can disrupt tight junctions between the epithelial cells and make them too porous, allowing undigested food particles and toxins to circulate throughout the body, further triggering immune system reactivity.

Vitamin D has a unique ability to tighten gap junctions in the intestinal lining to create a strong barrier that protects the body from foreign substances through the activation of vitamin D receptors (VDRs). VDRs play a critical role in mucosal barrier homeostasis by preserving the integrity of junction complexes and the healing capacity of the colonic epithelium.1

2. Glutamine for Gut Cells

Glutamine—the most abundant amino acid in the body—plays a vital role in maintaining mucosal integrity and a strong intestinal wall lining. For the mucosal epithelial cells in particular, this essential nutrient is needed for gut epithelial cell growth and differentiation. Glutamine provides fuel for metabolism inside the cell, regulating cell proliferation and repair and maintaining other healthy cellular functions. Glutamine also plays a key role in regulating epithelial tight junction proteins between the cells, limiting the development of intestinal permeability.2

In addition, glutamine has been associated with a better immune response and higher antioxidant capacity. In fact, recent research has even suggested a synergistic role between glutamine and a healthy balance of probiotic bacteria in the GI tract! Since the gut synthesizes only minute quantities of glutamine, epithelial cells mostly rely on glutamine supplied from the diet, especially in times of gut distress.


3. Anti-inflammatory Benefits of Chinese Skullcap 

Chinese skullcap (Scutellaria baicalensis) is an herb used in traditional Chinese medicine—often in combination with other plants or foods—to support various conditions and health functions. Getting past the quirky name, this amazing plant is associated with many benefits, such as inflammatory condition relief, decreasing levels of histamine, and curbing the inflammatory response to allergenic proteins by reducing cytokine levels and IgE antibodies, which provides needed support for individuals with allergies.

Two remarkable qualities Chinese skullcap also possesses include its chemical complexity and abundant antioxidants and flavones. One notable flavone is baicalin, which has been shown to help reduce inflammation-mediated tissue damage. Specifically, baicalin inhibits the NF-κB pathway of inflammation, contributing to a reduction in inflammasome activation.3 This mechanism is key for inflammatory stress relief and promoting the repair of affected tissues.


4. Beneficial Properties of Propolis

Propolis is a resinous substance comprised of tree bud material that bees produce. Yes, bees! They use this sticky substance to bind their hives together and keep out unwanted fungi and microbes, and we can also use propolis for its unique health benefits. Rich in flavonoids, propolis has a long history of use as a natural treatment for many health conditions, and growing research demonstrates its therapeutic activity, including antimicrobial, antifungal, antiviral and anti-inflammatory properties.

Caffeic acid phenethyl ester (CAPE) is one of the primary anti-inflammatory agents in propolis and has been used medicinally for thousands of years. Evidence suggests that CAPE blocks NF-κB activation, thus suppressing acute immune and inflammatory responses. Specifically, CAPE is a strong inhibitor of the induction of NF-κB. Also, CAPE directly inhibits the pro-inflammatory COX enzymes, helps neutralize secondary mediators of inflammation and has immuno-stimulating effects.4

Altogether, CAPE offers a multidimensional approach to maintaining normal inflammatory balance in the gut. Although the research into its applications for other health issues is ongoing, a millennium of traditional use says a lot about the anti-inflammatory benefits of propolis. 


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The Bottom Line

For your patients who need targeted support for gut barrier integrity, consider the vital role that vitamin D plays in gut barrier health. Vitamin D deficiency also may compromise the mucosal barrier, increasing susceptibility to mucosal damage. Regular supplementation with vitamin D is essential to help restore tight junction integrity. 

Along those lines, glutamine serves as a key nutrient to help repair gut cells by providing fuel and essential cofactors to support healthy cellular function and reduce intestinal permeability.

Chinese skullcap is another essential ingredient in your gut healing protocol because it helps maintain a healthy inflammatory balance and downregulates the effects of oxidative stress on gut tissue. Also, look to the traditional uses of propolis and the evidence supporting CAPE to help restore normal inflammatory balance in the gut.

Incorporating these noteworthy ingredients alongside good dietary choices and lifestyle habits offers clear clinical benefits for your patients by repairing the gut barrier, providing inflammatory relief and maintaining overall GI health.





Joseph Ornelas, PhD, DC is the Pillars of GI Health Brand Manager at Lifestyle Matrix Resource Center. He holds a PhD from University of Illinois with concentration in Health Economics, an MA degree in Public Policy from the Harris School at the University of Chicago, an MS degree in Health Systems Management from Rush University, and a DC degree from National University of Health Sciences. As a licensed provider and health economist, Dr. Ornelas has published numerous evidence-based clinical practice guidelines, helping to improve quality standards of care and provide value for health care practitioners across several specialty areas.




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2. Wang B, Wu G, Zhou Z, Dai Z, Sun Y, Ji Y, Li W, Wang W, Liu C, Han F, Wu Z. Glutamine and intestinal barrier function. Amino Acids. 2015 Oct;47(10):2143-54. doi: 10.1007/s00726-014-1773-4. Epub 2014 Jun 26. PMID: 24965526.
3. Patwardhan RS, Sharma D, Thoh M, Checker R, Sandur SK. Baicalein exhibits anti-inflammatory effects via inhibition of NF-κB transactivation. Biochem Pharmacol. 2016 May 15;108:75-89. doi: 10.1016/j.bcp.2016.03.013. Epub 2016 Mar 23. PMID: 27019135.
4. Tolba MF, Azab SS, Khalifa AE, Abdel-Rahman SZ, Abdel-Naim AB. Caffeic acid phenethyl ester, a promising component of propolis with a plethora of biological activities: a review on its anti-inflammatory, neuroprotective, hepatoprotective, and cardioprotective effects. IUBMB Life. 2013 Aug;65(8):699-709. doi: 10.1002/iub.1189. Epub 2013 Jul 11. PMID: 23847089.