# Nature's First Immune Supplement

Published March 2026 • 5 min read
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### Key Takeaways

- Colostrum is the first milk produced after birth — packed with immune factors
- Bovine colostrum contains IgG antibodies, lactoferrin, and growth factors
- Studies show reduced upper respiratory infections in athletes
- It may help repair intestinal permeability (leaky gut)

Before regular breast milk flows, mothers produce colostrum — a concentrated, golden liquid packed with immunoglobulins, antimicrobial peptides, and growth factors designed to jumpstart a newborn's immune system. Bovine (cow) colostrum supplements have gained traction for their potential to support adult immune function, gut health, and recovery. The science is early but intriguing.

## What's in Colostrum

Colostrum is fundamentally different from regular milk. It contains high concentrations of immunoglobulin G (IgG) — antibodies that bind to pathogens and toxins in the gut. Lactoferrin — an antimicrobial, anti-inflammatory iron-binding protein. Growth factors (IGF-1, TGF-beta) that promote tissue repair. And proline-rich polypeptides (PRPs) that modulate immune function.

Bovine colostrum is used because its immunoglobulin content is remarkably similar in structure to human colostrum, and cows produce it in quantities large enough for commercial supplementation. The IgG antibodies survive stomach acid (they're designed to function in the harsh neonatal gut) and reach the intestines intact, where they can bind to pathogens and toxins.

## What the Research Shows

The strongest evidence is for immune support in athletes — a population prone to upper respiratory infections due to exercise-induced immunosuppression. Multiple studies show that bovine colostrum supplementation reduces the incidence and severity of upper respiratory tract infections during heavy training periods.

For gut health, colostrum shows promise for reducing intestinal permeability. A study in Clinical Science found that colostrum prevented the increase in gut permeability caused by NSAIDs. The growth factors and immunoglobulins appear to support gut barrier integrity and reduce inflammation. For exercise performance, results are mixed — some studies show improved recovery and lean mass, others show no significant effect.

## How to Use Colostrum

Quality matters significantly: look for colostrum from grass-fed, pasture-raised cows, collected within the first 6 hours after birth (when immunoglobulin content is highest). It should be processed at low temperatures to preserve bioactive components. Third-party testing for immunoglobulin content is ideal — look for products guaranteed to contain at least 30% IgG.

Typical dose: 5-10g of powdered colostrum daily, taken on an empty stomach for best absorption of immunoglobulins. Start with a lower dose and increase gradually. Some people experience mild digestive changes initially. Colostrum is generally well-tolerated, though those with dairy allergies should avoid it. It pairs well with other gut-support strategies: prebiotic fibre, glutamine, and a whole-food diet.

#### Who Is This For?

Anyone interested in evidence-based longevity strategies, health optimisation, and understanding the latest research on ageing and healthspan.

#### Consult Your Doctor If...

You are pregnant, breastfeeding, taking prescription medications, or have a pre-existing medical condition. This content is educational and does not replace professional medical advice.

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Medical Disclaimer: This content is for informational purposes only and does not constitute medical advice. Always consult with a qualified healthcare provider before starting any new supplement or making changes to your health regimen.

#### Sources & References

1. British Journal of Sports Medicine - Colostrum and Upper Respiratory Infections
2. Clinical Science - Colostrum and NSAID-Induced Gut Permeability
3. Nutrients - Bovine Colostrum and Immune Function Review
4. Journal of the International Society of Sports Nutrition - Colostrum and Exercise