The ultimate guide to supplements for leaky gut

The relationship between over exercising and gastrointestinal health has gained a fair bit of attention in recent years, particularly in relation to the phenomenon known as ‘leaky gut’ or increased intestinal permeability

We’re going to discuss leaky gut first within the context of over-exercising. However, you can also think of this article as a comprehensive guide to some additional supplemental strategies that anyone — regardless of the etiology or ‘cause’ of their LG’ — can use to manage intestinal permeability. These can be stacked on top of the fungal protocol if you find you need some additional support.

(If you need help with this, drop a question in the Members or Group Q/A chat, or consider booking a one on one consult with me directly. You can find the link for that bellow. Patreon members get 15% off all consults)

http://calendly.com/fowlerfitness1 (consult)

What is ‘leaky gut’?

When the integrity of the intestinal barrier is compromised, harmful substances like endotoxin can enter the bloodstream, which often leads to systemic inflammation. Low grade, chronic endotoximia is one of the most common causes of elevated C-reactive protein, or ‘CRP’ for short (a marker of system inflammation), in otherwise ‘healthy’ individuals. Meaning people who exercise regularly and eat a generally well-balanced diet.

The consequences of leaky gut extend beyond gastrointestinal pathology. As I mentioned, the translocation of bacterial endotoxins and other harmful substances into the bloodstream can trigger systemic inflammation, contributing to a range of health issues, including metabolic dysfunction, brain fog, and impaired immune responses. Athletes experiencing leaky gut and the associated systemic endotoximia may also face increased susceptibility to infections, particularly upper respiratory tract infections, which are very common among endurance athletes.

Avaliable evidence suggests that exposure to chronic, systemic endotoxin in the bloodstream — from intestinal permeability — is linked or partially implicated in virtually all major chronic diseases including

1. cancer

2. Various forms of autoimmunity

3. Skin conditions

4. Neurodegenerative disorders

5. Depression, brain fog, anxiety and other mood disorders

6. Psychiatric conditions like schizophrenia, BPD, and mania.

7. Infection

8. Insulin resistance and metabolic dysfunction

9. Arthritis and MSK conditions

The intestinal barrier is primarily composed of epithelial cells connected by tight junctions, which regulate the passage of substances between the gut lumen and the bloodstream. This is important because the gut DOES need to be selectively permeable in order to absorb nutrients. ‘Selectively permeable’ is the key word here.

Key proteins involved in maintaining the tight junctions include claudins and occludins. Endurance training, particularly at high intensities, can disrupt the expression and function of those proteins, leading to increased intestinal permeability.

While moderate exercise is generally associated with positive health outcomes, excessive endurance training in particular can have detrimental effects on gut barrier integrity. While this is most commonly associated with extreme endurance training (running marathons etc) in the literature, I believe this very likely applies to most forms of exercise done in excess. This is particularly relevant for glycolytic and or ‘mixed demand’ sports (any sport requiring a high degree of both aerobic and anaerobic fitness) like soccer, tennis, wrestling/MMA and basketball.

Intense physical exertion generates oxidative stress, which can also damage cellular structures, including those in the intestinal lining. The production of

ROS during prolonged and intense exercise often contributes to the oxidation of tight junction proteins. This ultimately results in dysfunction and subsequent leakage of intestinal contents into the bloodstream. endurance training is associated with elevated levels of pro-inflammatory cytokines like IL-6 and TNF-a, which will further exacerbate intestinal barrier dysfunction.

During prolonged endurance activities in particular, blood flow is redirected away from the gastrointestinal tract to support working muscles, leading to ischemia and hypoperfusion of the intestinal mucosa. This reduced blood supply impair the mucosal integrity and contributes to the breakdown of the epithelial barrier. In my opinion, this is a phenomena likely more attributable to extreme endurance training events, particularly ultra-marathons, triathlons etc. I don’t really see this being a huge concern with other forms of training, but it is worth mentioning as a possible contributing factor.

Research HAS consistently shown that endurance athletes experience a higher prevalence of gastrointestinal disorders and training associated diarrhea. For instance, some studies on ultramarathon runners and triathletes show significant increases in intestinal permeability markers, such as the lactulose/rhamnose ratio and levels of intestinal fatty acid-binding protein following prolonged, intense training sessions. These markers are indicative of mucosal degradation and the potential for systemic inflammation due to the translocation of many gut-derived substances into systemic circulation.

One study highlighted that just 60 minutes of vigorous endurance training at 70% of maximum work capacity can lead to significant increases in intestinal permeability, suggesting that even relatively short bouts of high-intensity exercise can increase the ‘leakiness’ of the gut.

It’s important to realize that transient increases in intestinal permeability don’t necessarily indicate that we shouldn’t be doing endurance training or exercising hard in general. Its easy to take a snapshot of something in time (like elevated cortisol from caffeine, or decreased testosterone during exercise) and use this as validation to demonize something. I don’t think this is the right conclusion to draw. the effects of endurance training on gut permeability appear to be CUMULATIVE, with chronic high-intensity training leading to persistent alterations in gut barrier function.

There’s a few conclusion we can draw here

1. Training loads need to be managed properly

2. Very frequent, extreme endurance training likely isn’t healthy (all training is a form of stress

3. Those with health issues (particularly gut issues) may need to start slow.

What can you do?

Effective training load management is crucial, but I recognize that not everyone is ready to adjust their routines, especially when pursuing specific fitness goals or when faced with demanding circumstances, such as a sport coach who won't allow needed rest. In these situations, it's essential to have some fallback strategies in place.

Spore based probiotics:

spore based probiotics should always be at the top of the list. If you’re on a budget and can’t afford expensive supplements, this would be an ideal first priority. Randomized controlled trials have repeatedly demonstrated that spore based probiotics reduce gut permeability and endotoxemia. One paper demonstrated that 30 days of spore-based probiotic supplementation led to a significant reduction in dietary endotoxemia and inflammatory biomarkers in participants.

Other papers have shown that spore-based probiotics can alleviate symptoms associated with leaky gut by reducing the overgrowth of pathogenic bacteria, which are often responsible for gut inflammation and permeability issues. Spores also help to maintain the health of the mucosal barrier. Spores do this by directly increasing the production of butryate producing bacteria. Butyrate is a short chain fatty acid that acts as a direct fuel for intestinal cells.

My favorite spore based probiotic is the Just Thrive, and you can use the code GRANTFOWLER15 for an addition 10% off. During times of intense psychological or training stress, considering a double dose. If this is your first time taking spores, start with half a dose to assess tolerance. https://justthrivehealth.com/?rfsn=4153843.ed61ca

BPC-157:

BPC is a popular peptide, often known for its role in healing injuries and managing various musculoskeletal conditions. Many are unaware that’s it’s also been shown to address leaky gut syndrome through several mechanisms. For one, BPC 157 stabilizes the intestinal barrier and exerts cytoprotective effects on various cell types, including those in the gastrointestinal tract. It enhances the survival of intestinal cells under stress conditions, such as exposure to nonsteroidal anti-inflammatory drugs and other irritants. BPC also modulates inflammatory responses in the gut.

BPC is best used in cycles of 1-2 months of 500mcg daily on an empty stomach, particularly during intense training cycles or competition. You can find my favorite brand of oral BPC bellow, along with a discount code for 10% (GRANTFOWLER10)

https://infiniwell.com/?rfsn=5349339.0c2b41

L-glutamine:

glutamine is an amino acid that plays an important role in maintaining gut health, as it acts as direct fuel for enterocytes. Glutamine is the primary, preferred energy source for enterocytes, aka our intestinal cells. Adequate levels of glutamine is extremely important to help prevent the breakdown of tight junctions that can lead to increased intestinal permeability. In endurance athletes, l-glutamine is rapidly depleted by intense training, likely contributing to the increased permeability seen in these athletic populations. The combination of glutamine and BPC seems to be a knockout solution for promoting intestinal homeostasis under extreme stress.

5-10g daily is ideal. The dosage can be upped on training days, even up to 20g. See what works best for you.

Bovine serum Immunoglobulins — IgG, IgM, and IgA are bovine derived immunoglobulins that have demonstrated marked clinical success in mopping up endotoxins and mycotoxins directly. Unlike other binders, they won’t chelate your minerals and nutrients. This is one of the reasons they’re used in the fungal protocol to prevent die off reactions and diarrhea. If you find you’re expericing a lot of digestive discomfort during or after extreme bouts of intense training, dosing bovine serum immunoglobulins prior to training might be your best friend. They’ve also been shown to directly support a healthy immune system, mucosal and intestinal barrier function. You can find them along with some other useful dosing recommendations in the fungal protocol.

1-2 servings daily is usually sufficient.

Gastrointestinal peptide bio-regulators (Ovagen and stakamort)

Peptide bio-regulators are short, bovine derived peptides that regulate the function of the target organs they’re sourced from. For example, the peptide bio-regulator for the gastrointestinal system is derived from bovine GI tissue. You can think of them almost as more refined, concentrated versions of many popular ‘organ’ supplements on the market. The difference is that they work far better and have numerous clinical studies backing their efficacy in Russia and some of the post Soviet states. The GI bio-regulator has been shown to restore the health and function of the intestinal and mucosal barrier. The great thing about bio-regulators is that you only need to use them sparingly. A short, 10-20 day course is often all you need to reap the benefits for many months. Many of the bio-regulators continue to exert their positive, organoprotective and regulatory benefits for up to 5-6 months after discounted.

2-4 capsules for 10-20 days is ideal. The cycle can be repeated every 2-6 months depending on your needs. Both Ovagen and stakamort are GI bio-regulators. Ovagen can also be done as an injectable. CanLabs is my preferred source, with daily dosing around 1mg for 10-20 days.

https://peptide-bioregulator.com/?rfsn=7063681.259e4da

Zinc carnosine:

Zinc carnosine is a combination of zinc and the dipeptide carnosine, which has been studied for managing leaky gut and ulcers . Zinc carnosine specifically has been shown to strengthen the intestinal barrier by promoting the integrity of tight junctions between epithelial cells, reducing the passage of harmful substances into endotoxin in the bloodstream. The combination of zinc and carnosine also supports the healing of the gastrointestinal mucosa. It’s important to keep in mind that we are specifically talking about zinc carnosine here. While other forms of zinc might be great for improving zinc status, the combination of zinc with carnosine is what produces the great benefits we see for gut barrier function.

you can find zinc carnosine on the mitolife website, and you can use the code GRANTFOWLER15 for 10% off. This product is also frequently on sale (often as cheap as $10-15 for a 1-2 month supply) so I would recommend checking often. 16mg is usually a good dose for GI support, although some individuals may benefit from going higher (up to 32mg, so a double dose) on hard training days. Be sure to balance higher doses with copper rich foods like liver and oysters.

Saccromyces boulardii

Saccromyces is another great probiotic years that can benefits for improving intestinal barrier function. See the full saccromyces boulardi article bellow for sourcing, dosing, and protocols.

https://www.patreon.com/posts/117370750?utm_campaign=postshare_creator

KPV peptide:

KPV is another phenomenal peptide for GI barrier support, avaliable in both injectable and oral forms. Here’s part of an article I wrote on KPV: ‘The peptide also acts via the transporter hPepT1, which is expressed in both immune and intestinal epithelial cells. This targeting allows KPV to effectively reduce the incidence of colitis induced by chemical agents such dextran sulfate sodium and trinitrobenzene sulfonic acid.

In layman’s terms, KPV protects the intestines from toxic chemicals and carcinogens. KPV treatment has been observed to decrease levels of pro-inflammatory cytokines like TNF-α, IL-1B, and IL-6 without significantly altering the levels of anti-inflammatory cytokines such as IL-10. This suggests that KPV primarily acts by downregulating inflammation itself AND boosting pro-resolving, anti-inflammatory responses. The enhancement of mucosal healing is a critical goal in UC treatment. Studies utilizing electrical impedance sensing technology have shown that wounded epithelial layers treated with KPV suspensions exhibited significant recovery compared to untreated controls. This indicates that KPV not only reduces inflammation but also promotes the healing of the intestinal lining itself. You can read the rest of the article below.

KPV is often dosed around 250-500mcg for 1-2 months. Both orally and or as an injectionIf can be used similar (and in concjuction) with BPC-157. You can find my favorite oral KPV bellow

https://integrativepeptides.com/product/kpv-ultra-oral-spray/

https://www.patreon.com/posts/115793386?ut (KPV article)

Tributyrin

Tributyrin is a triglyceride that is naturally found in dairy fats and is a source of butyrate, a short-chain fatty acid produce by your gut bacteria. Butyrate is produced in the gut through the fermentation of dietary fibers by gut microbiota as we mentioned. It plays a crucial role in maintaining gut health, particularly in the colon, where it serves as a primary energy source for colonocytes (the cells lining the colon) and has anti-inflammatory properties as well. Tributyrin is often doses around 3 capsules daily. I like the brand healthyGut. If can cause GI distress and bloating, so it may be good to start off with one capsule. I recommend using tributyrin in short courses of 1-2 months or during intense training cycles. Consistently taking high doses of butryate may lower our own endogenous production, so it’s good not to use it for prolonged periods of time.

https://healthygut.com/product/tributyrin-x/?

HMO’s

HMOs, or human milk oligosaccharides, are a unique type of prebiotic fiber found in human breast milk. They are complex carbohydrates composed of various sugar molecules that are not digestible by humans but serve as a food source for beneficial gut bacteria. HMOs have a distinctive structure that sets them apart from other dietary fibers. They consist of complex arrangements of monosaccharides, while many other fibers are simpler, such as cellulose or inulin. They are readily found in human breast milk, and contribute significantly to the health of our immune system in early childhood development

Another one of the fascinating functions of HMOs is their ability to prevent pathogenic bacteria and yeasts (Candida) from adhering to the intestinal lining. They do this through a mechanism called ‘decoy’ action. Pathogens often attach to specific receptors on the gut lining to establish infection. HMOs can mimic these receptors, binding to the pathogens instead and effectively preventing them from sticking to the gut wall. This prevents pathogen induced intestinal damage. HMO’s also signicantly improve the mucosal barrier, essentially ‘sealing up’ the gut lining.

I like the brand pure hmo. One serving daily is sufficent

PEMF therapy

PEMF is believed to stimulate cellular repair processes, which I think could possibly aid in the recovery of the intestinal lining and restoring tight junction integrity. We don’t have tons of research on this. Anecdotally, I have found that a lot of my colitis and IBS clients have responded extremely really well to intermittent (2-3x a week) , HIGH INTENSITY PEMF done directly on the abdomen. I think this can be a really underrated temporary solution for symptoms management, especially in severe cases where relief is needed. PEMF therapy can enhance microcirculation, which would theoretically improve nutrient delivery and waste removal. Given what I’ve seen PEMF do for a variety of tissue injuries, I suspect the benefits are conferable to the GI as well.

See the PEMF buyers guide for more on PEMF

Marshmallow root

Marshmallow can helps to encourage the formation of that protective, mucous like coating in the digestive tract. For individuals with burning or associated GI symptoms of intestial permeability, MR can be a good temporary supplement for managing symptoms and improving local inflammation