Gut Barrier & Microbiome

Written by Dr. Ryan Kneessi, ND

The mechanisms this protocol supports

The cells of the gut lining are held together by tight junctions and protected by a layer of mucus. Beneficial bacteria feed on fiber and produce short-chain fatty acids such as butyrate, which help nourish those cells and support healthy immune signaling.

When the barrier is stressed, larger particles can pass through and activate the immune system, which is often described as increased intestinal permeability. A diverse microbiome, a healthy mucus layer and calm immune signaling all work together to keep the barrier strong.

Research has linked increased intestinal permeability and microbial imbalance with inflammatory bowel conditions and some autoimmune conditions. My article on intestinal permeability explains this in more depth.

What is in the protocol

The exact products and directions are listed in the Fullscript plan, and here is what each one is commonly used to support.

Ther-Biotic Synbiotic from Klaire Labs is a multi-strain probiotic paired with a prebiotic to support a diverse, balanced microbiome. GI-Resolve from Biotics Research is a powder that combines zinc carnosine, L-glutamine, N-acetyl glucosamine, MSM, deglycyrrhizinated licorice, okra and aloe, which are commonly used to support the lining of the stomach and intestines. Mitopure from Timeline provides urolithin A, which is being studied for its role in mitophagy, the process cells use to recycle worn-out mitochondria. It has also been studied for its role in supporting gut barrier function.

Related protocols you may find helpful include Gut Lining & Inflammatory Balance.

How to use it thoughtfully

Please talk with your provider before starting, especially if you take medications, are pregnant or nursing, or have a health condition. This page does not list amounts, so follow the label or the specific guidance your provider gives you.

When you can, add one product at a time so it is easier to notice how you feel. Sleep, nourishing food, daily movement and stress care are the foundation, and supplements are meant to build on them.

What the research shows

This protocol has not been tested as a whole in a clinical trial, so the studies below cover its main ingredients.

In a 2019 trial by Zhou and colleagues, 106 adults with post-infection IBS and increased gut permeability took 5 grams of glutamine three times daily or placebo for eight weeks. Symptoms improved meaningfully in 79.6% versus 5.8%, and permeability normalized only with glutamine. It was a single-center trial in a narrow group.

Zinc carnosine was tested by Mahmood and colleagues in 2007. In 10 healthy volunteers taking the anti-inflammatory drug indomethacin for five days, gut permeability roughly tripled with placebo but did not rise significantly with 37.5 mg of zinc carnosine twice daily. The human part of the study was very small.

For probiotics, a 2018 meta-analysis by Ford and colleagues of 53 trials with 5,545 adults with IBS found that some combinations and strains helped overall symptoms and pain, but could not say which work best.

Frequently asked questions

Sources

• Johansson ME, et al. The inner of the two Muc2 mucin-dependent mucus layers in colon is devoid of bacteria. Proc Natl Acad Sci U S A 2008. PMID: 18806221. https://pmc.ncbi.nlm.nih.gov/articles/PMC2567493/
• Parada Venegas D, et al. Short Chain Fatty Acids (SCFAs)-Mediated Gut Epithelial and Immune Regulation and Its Relevance for Inflammatory Bowel Diseases. Front Immunol 2019. PMID: 30915065. https://pmc.ncbi.nlm.nih.gov/articles/PMC6421268/
• Camilleri M. Leaky gut: mechanisms, measurement and clinical implications in humans. Gut 2019. PMID: 31076401. https://pmc.ncbi.nlm.nih.gov/articles/PMC6790068/
• Fasano A. Leaky gut and autoimmune diseases. Clin Rev Allergy Immunol 2012. PMID: 22109896. https://pubmed.ncbi.nlm.nih.gov/22109896/

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