Research shows that egg yolk antibodies can help combat a variety of pathogens:

Treatment of Gut Bacterial Infections

Egg yolk antibodies have been extensively studied for combating a wide range of bacterial infections, including H. pylori, E. coli, C. difficile, and S. aureus.¹

H. pylori infection affects half of the human population, and it is the most common cause of gastritis, gastric ulcers, and gastric cancer.²⁻³ In fact, it is the most common infectious agent that causes cancer globally.⁴ The most common treatment for H. pylori is antibiotics, but this cannot be applied on a widespread scale due to mounting drug resistance. H. pylori is currently left untreated in most asymptomatic individuals.⁵

Egg yolk antibodies specific to H. pylori antigens are a promising alternative to antibiotic therapy. In one clinical study, yogurt with egg-derived antibodies against H. pylori urease suppressed H. pylori infection with no side effects.⁶ Similarly, egg yolk powders with H. pylori urease-specific antibodies were found to reduce H. pylori levels and aid the treatment of gastritis.⁷

Egg yolk antibodies against other bacteria such as Salmonella, C. difficile, E. coli, C. jejuni, and S. aureus have also been developed. For example, egg-derived anti-C. difficile antibodies have been shown to prevent recurrent C. difficile infections and enhance survival rates in hamsters.⁸⁻⁹ In another study, egg-derived Salmonella-specific antibodies taken orally reduced Salmonella colonization in young chicks.¹⁰ In yet another case, egg-derived antibodies specific to E. coli, taken orally in microcapsules, reduced the severity of diarrhea in piglets.¹¹ These studies, among dozens of others, support the promise of egg-derived antibodies in preventing and treating a variety of bacterial infections.

References:

1. Lee, L. et al. "Immunoglobulin Y for potential diagnostic and therapeutic applications in infectious diseases." Frontiers in Immunology 2021.

2. Zhang, L. et al. "Potential therapeutic effects of egg yolk antibody (IgY) in Helicobacter pylori infections — A review." Journal of Agricultural and Food Chemistry 2021.

3. MD Anderson Cancer Center. "H. pylori and your stomach cancer risk." 2021.

4. Parkin, D.M. "The global health burden of infection-associated cancers in the year 2002." International Journal of Cancer 2006.

5. Cleveland Clinic. "H. pylori infection." 2021.

6. Horie, K. et al. "Suppressive effect of functional drinking yogurt containing specific egg yolk immunoglobulin on Helicobacter pylori in humans." Journal of Dairy Science 2004.

7. Suzuki, H. et al. "Effect of dietary anti-Helicobacter pylori-urease immunoglobulin Y on Helicobacter pylori infection." Alimentary Pharmacology & Therapeutics 2004.

8. Mulvey, G.L. et al. "Therapeutic potential of egg yolk antibodies for treating Clostridium difficile infection." Journal of Medical Microbiology 2011.

9. Kink, J.A. and Williams, J.A. "Antibodies to recombinant Clostridium difficile toxins A and B are an effective treatment and prevent relapse of C. difficile-associated disease in a hamster model of infection." Infection and Immunity 1998.

10. Rahimi, S. et al. "Prevention of Salmonella infection in poultry by specific egg-derived antibody." International Journal of Poultry Science 2007.

11. Wang, Z. et al. "Protective effect of chicken egg yolk immunoglobulins (IgY) against enterotoxigenic Escherichia coli K88 adhesion in weaned piglets." BMC Veterinary Research 2019.

Image by NIAID, CC BY 2.0

Respiratory Disease Prevention

Egg yolk antibodies that specifically bind to respiratory viruses (e.g., flu or COVID-19 virus) have been developed by researchers across the globe.¹

These antibodies can be used nasally or orally to block viral entry into the respiratory tract.²⁻³

During the COVID-19 pandemic, researchers at Stanford University and the University of Technology Sydney collaborated to develop egg yolk antibodies as a nasal spray for COVID-19 prevention. Through lab assays, they showed that the antibodies were able to bind equally effectively to different variants of the SARS-CoV-2 virus. They also completed a Phase 1 clinical trial proving that the antibodies had excellent safety in humans.⁴

Since they are very stable and can be formulated against different pathogens, egg yolk antibodies are a promising way to control current and future pandemics.⁵⁻⁶

References:

1. Lee, L. et al. "Immunoglobulin Y for potential diagnostic and therapeutic applications in infectious diseases." Frontiers in Immunology 2021.

2. Wallach, M.G. et al. "Cross-protection of chicken immunoglobulin Y antibodies against H5N1 and H1N1 viruses passively administered in mice." Clinical and Vaccine Immunology 2011.

3. Shen, H. et al. "Anti-SARS-CoV-2 IgY isolated from egg yolks of hens immunized with inactivated SARS-CoV-2 for immunoprophylaxis of COVID-19." Virologica Sinica 2021.

4. Frumkin, L.R. et al. "Egg-derived anti-SARS-CoV-2 immunogloublin Y (IgY) with broad variant activity as intranasal prophylaxis against COVID-19." Frontiers in Immunology 2022.

5. Frumkin, L.R. et al. "COVID-19 prophylaxis with immunoglobulin Y (IgY) for the world population: The critical role that governments and non-governmental organizations can play." Journal of Global Health 2022.

6. Wallach, M.G. "Opinion: the use of chicken IgY in the control of pandemics." Frontiers in Immunology 2022.

Image by NIAID, CC BY 2.0

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How do egg yolk antibodies compare with human antibodies?

Egg yolk immunoglobulin Y (IgY) antibodies have similar immune functions as human immunoglobulin G (IgG) antibodies. However, the structure of IgY antibodies is slightly different, meaning that they do not activate your own immune response. This makes them safer than mammalian IgG antibodies. Egg yolk IgY antibodies are also far more stable in the gut. In fact, they are 20-fold more stable than IgG at 60°C for up to 8 hours!

Most importantly, egg yolk IgY antibodies are ethically and harmlessly sourced. IgG antibodies are extracted from serum, meaning that the animals must be bled, which is often distressing and not sustainable. IgY antibodies can give immune benefits to both chickens and humans, serving as a sustainable way to boost your immunity.

How long do egg yolk antibodies stay active in the body?

Egg yolk antibodies are extremely stable – Their resistance to heat and pH lets them stay active for hours in the mouth and gut. In one clinical study, active egg yolk antibodies were still detected in the saliva of 18 out of 19 people the morning after an antibody mouth rinse.

Stomach enzymes will eventually digest the antibodies over a few hours and safely eliminate them from your body. But the antibodies will have already done their job, since they work immediately to bind their targets. That’s why it is important to take the antibodies daily to keep your defenses up; it's even better to take them multiple times a day. Feel free to take the antibodies with a sugary drink, since sugar has been shown to stabilize the antibodies in acidic conditions!

Do egg yolk antibodies have any side effects?

Since IgY antibodies are entirely derived from egg yolk, they are extremely safe for humans. Unlike vaccines and mammalian IgG antibodies, they do not elicit your body to mount an immune response, instead acting to reinforce your own immune system. However, egg yolk antibodies are not recommended for people with egg allergies.

In a study with anti-H. pylori urease IgY antibodies, “no adverse effects or any complications” were observed in 22 subjects taking the antibody-fortified yogurt for 4 weeks. Similarly, "none of the volunteers experienced significant side effects at any time" for 17 subjects taking an egg yolk powder with anti-H. pylori urease IgY antibodies over 4 weeks. In another study, anti-SARS-CoV-2 egg yolk antibodies had “excellent safety and tolerability” when taken in a nasal drop, passing a Phase 1 clinical trial. Altogether, decades of scientific evidence point to egg yolk antibodies being exceptionally safe for human consumption.

How long will it take to see an effect from egg yolk antibodies?

In clinical studies targeting H. pylori infection, daily consumption of anti-H. pylori urease IgY antibodies led to significant reductions in urea breath test levels in 2 weeks and 4 weeks. These studies used dosages of roughly half an egg a day (4.5 g of egg yolk powder, with 7-9 g from a typical egg) and a third of an egg a day (2.7 g of defatted whole egg powder, with 9-10 g from a typical egg), respectively. 

There are typically 50-100 mg of egg yolk antibodies per egg, so the estimated amount used in these studies was ~15-50 mg a day.