The Gut Blueprint

By Eugene Capitano, DC MSc (Neuroscience & Psychology of Mental Health)
ACSM-Certified Exercise is Medicine® Practitioner and Personal Trainer
DOWNLOAD THE FULL SCIENTIFIC PDF WITH REFERENCES BELOW

Why Your Microbiome Holds the Secret to Muscle Growth — And How “Clean” Protein Powders Get It Wrong

By Eugene Capitano, DC MSc (King’s College London) ACSM-Certified Exercise is Medicine® Practitioner and Personal Trainer Founder, TLC NeuroMicrobiome Labs Inc.

“You’re not what you eat — you’re what your microbiome allows you to absorb.

After spending a year reviewing hundreds of peer-reviewed studies on the gut–muscle axis, I realized something game-changing:

We’ve been optimizing the wrong variable.

For years, athletes and clinicians (myself included) have obsessed over macros, grams of protein, timing, and bioavailability — while overlooking the true biological gatekeeper of muscle growth: the gut microbiome.

Muscle protein synthesis (MPS) doesn’t begin when amino acids reach your bloodstream, it begins when your gut bacteria meet your food.

A balanced microbiome produces short-chain fatty acids (SCFAs) like butyrate, which:

• Strengthen intestinal barrier integrity
   
• Reduce systemic inflammation
   
• Prime mTOR, the master regulator of muscle protein synthesis
   

When your gut barrier is intact, nutrients drive anabolism.
When it’s compromised, bacterial toxins such as lipopolysaccharide (LPS) leak into circulation — triggering inflammation that suppresses mTOR and activates catabolic pathways

Recent studies reveal that even low-dose exposure to common sweeteners and emulsifiers can impair glycemic control and disrupt gut microbial balance. 

Yet these same compounds are found in almost every “clean” protein on the shelf.

In the News: What Experts Are Saying

A 2025 HuffPost feature echoed growing concerns about additives in commercial protein powders — aligning with TLC PureOrigin’s mission to protect the gut–brain axis and redefine “clean” through microbiome-safe formulation.

“Protein powders often contain artificial sweeteners that wreak havoc on your gut microbiome,” says neuroscientist Friederike Fabritius. “A healthy and robust internal microbiome is vital for great brain health — most of our neurotransmitters are produced in the gut.”

Neurologists Share The #1 Food They Never (Or Rarely) Eat
By Leigh Weingus – HuffPost, November 29, 2025
Read the full article → https://www.huffpost.com/entry/worst-foods-for-brain-health-goog_l_6920a6cee4b0536e01acdbb4?utm_source=firefox-newtab-en-us

That whey with stevia, that natural vanilla flavor, that maltodextrin for texture — they’re not as harmless as they sound.

Here’s what the data actually show:

Non-nutritive sweeteners such as sucralose and stevia glycosides reduce beneficial butyrate-producing bacteria—notably Faecalibacterium, Roseburia, and Eubacterium.

In the RapidAIM human microbiome model, Wang (2021) found that stevioside and rebaudioside A altered microbial enzyme expression involved in butyrate synthesis across multiple donor microbiomes.

Some manufacturers argue that the stevia content in their products is minimal. While this may be true by weight, even low concentrations of stevia glycosides have been shown in ex vivo human microbiome models to modify the abundance and enzymatic activity of butyrate-producing bacteria such as Faecalibacterium and Roseburia. The effect is not toxic but functional—subtle shifts that can influence gut barrier integrity, metabolic signaling, and potentially muscle anabolic sensitivity over time.

They’re often dissolved in maltodextrin, glycerol, or mono/diglycerides — emulsifiers proven to disrupt mucosal integrity, decrease microbial diversity, and increase intestinal permeability.

The Naimi et al. (2021) MBRA study showed that maltodextrin:

• Reduces microbial diversity
   
• Suppresses beneficial taxa
   
• Increases LPS and flagellin production — drivers of metabolic endotoxemia and inflammation
   

These effects mirror those of industrial emulsifiers like Polysorbate 80 and CMC, placing maltodextrin squarely in the category of microbiome disruptors.

Bottom line: these additives quietly push the body toward inflammation — tipping the scale so that muscle breakdown exceeds synthesis, no matter how high your protein intake.

When the gut barrier breaks down:

1. LPS enters the bloodstream, activating NF-κB.
    
2. Cytokines like TNF-α and IL-6 rise.
    
3. Insulin sensitivity drops, and mTOR signaling is bluntedFrom Leaky Gut to Anabolic Resi….
    

Even in healthy athletes, chronic dysbiosis can reduce MPS. Reduced SCFA availability then deprives intestinal cells of energy, weakening nutrient absorption and hormonal signaling.

The result: your macros look perfect on paper — but biologically, you’re running a deficit.

“Clean” can no longer mean “no artificial colors.”

True nutritional integrity requires microbiome-compatible formulation — ingredients proven not to harm gut balance.

That’s why we developed the Ultra Clean™ Standard, built on scientific verification rather than marketing claims.

Every ingredient must meet three non-negotiable criteria:

1. No microbiome disruption in human or ex-vivo models.
    
2. No barrier compromise at realistic consumption levels.
    
3. No inflammatory activation in epithelial or immune cells.
    

Anything less is like pouring premium fuel into an engine with a cracked fuel line.

You can’t out-train, out-supplement, or out-macro a damaged gut.
The next evolution in sports nutrition won’t be about more protein or faster digestion — it will be about protecting the anabolic environment where growth truly begins: your gut.