Life Extension Magazine®

Couple cooking proper diet and bacteriophages for balanced gut microbiome

Phages Improve Intestinal and Immune Health

By selectively targeting harmful bacteria such as E. coli, beneficial flora exponentially multiply. The effect is improved intestinal and immune health.

Scientifically reviewed by Dr. Gary Gonzalez, MD, in August 2023. Written by: Michael Downey, Health & Wellness Author.

People are surprised to learn that about 70% of the human immune system resides in gastrointestinal-associated tissue (known as gut-associated lymphoid tissue).

The immune system relies on the presence of healthy intestinal bacteria to protect the body from illness.1,2

Age, poor diet, medications, and stress can upset the delicate balance of good to bad bacteria.3

An imbalanced gut microbiome contributes to autoimmune disorders, metabolic syndrome, diabetes, chronic fatigue, nonalcoholic fatty liver disease, obesity, and more.4-12

Life Extension® readers understand the value of taking a quality probiotic to help balance the microbiome and strengthen the immune system.

Incorporating bacteriophages with a probiotic takes this intestinal health strategy a step further.

Bacteriophages selectively target specific, harmful bacteria while leaving beneficial microbes to flourish. This was pioneered in Europe before the advent of antibiotics.13-15

Bacteriophages are especially beneficial when used in conjunction with probiotics because they act like advanced troops to clear the way for beneficial bacteria to flourish.

Laboratory studies show that when probiotics and phages are used in combination, beneficial bacteria grow to thousands of times their baseline rate.16,17

What you need to know

  • Supplementation with potent probiotics is essential to supporting health throughout the body.
  • Now, safe bacteriophages are available that selectively kill off undesirable bacteria, making room for beneficial bacteria to grow.
  • Studies show that taking probiotics with targeted phages removes competing, unhealthy microbes to allow the beneficial probiotics to attain huge numbers.
  • This approach can powerfully optimize digestive health and overall wellness by balancing the digestive tract microbiome.

How Gut Bacteria Affects the Entire Body


The microbiome comprises the trillions of microorganisms that live in the human gut.18 Today we know that the microbiome plays a critical role in health and disease.

The increased consumption of processed carbohydrates, meats, fats, preservatives, and other additives can alter our microbiome.19-21 In addition, antibiotic overuse kills both healthy and bad bacteria.22-24 As a result, our gut microbiome becomes disrupted and imbalanced.

Over time, an imbalance in the ratio of good to bad bacteria can trigger the development of chronic diseases in multiple areas of the body—not just those associated with the gut.4-12

We also recognize that allergic disorders, asthma, and even obesity are related to an unhealthy population of intestinal bacteria.25,26

Fortunately, you can do something about it. By shifting your gut microbiome toward a more balanced, healthy profile, you can induce a positive impact on your overall health and well-being.18

Boosting Probiotics with Phage Therapy

A unique treatment known as phage therapy uses bacteriophages to selectively reduce harmful bacteria, making way for beneficial probiotic organisms to flourish. Using probiotics along with bacteriophages can quickly and effectively rebalance the gut microbiome.27

Bacteriophages are submicroscopic packages of DNA or RNA enclosed in a protein envelope, and each one is chosen for its ability to attach to a unique strain of unwanted bacteria in the intestines. In other words, they selectively target specific, harmful bacteria, while leaving beneficial microbes to flourish.

The Long History of Phage Therapy

Using phages to control bacterial illnesses was pioneered in Eastern Europe before World War I.13-15

By the 1940s, industrial giants such as Eli Lily and L'Oréal had developed bacteriophage "cocktails" for treating infections, but the advent of antibiotics quickly stole the spotlight (even though the effectiveness of phages was never in question).22

We've come to recognize that one of the key drawbacks to antibiotics is that they employ a mass-killing technique that eliminates both detrimental and healthy bacteria, leaving us vulnerable to attack by other organisms.28 In direct contrast to antibiotics, bacteriophages specifically eliminate only the detrimental bacteria while leaving healthy bacteria untouched.

Because of these targeted actions, the food industry now uses bacteriophages to control disease-causing organisms.29-31 Many of these phages are classified by the FDA as GRAS (generally recognized as safe) and are commonly used for controlling bacteria ranging from Listeria in cheese and E. coli in meat, to E. coli on food-contact surfaces, to Salmonella in food.

A phage cocktail is effective within hours, not days, and in very small doses.16 As an added benefit, it functions not only in the large intestine, where bacterial imbalance (dysbiosis) is a problem, but also in the small intestine, where undesirable bacterial overgrowth can occur.

Animal studies have validated the benefits of using probiotics and phage therapy together. For example, when combined with a probiotic in an animal model, there was an exponential increase in beneficial bacteria with a parallel decrease in unfriendly flora such as E. coli.32-34

Let's examine more of the remarkable findings on this novel therapy.

Bacteriophage Potency

Bacteriophage Potency  

Scientists established the efficacy of bacteriophages in promoting healthy bacteria in a series of lab experiments.

In the first study, culture dishes were prepared with a beneficial bacterium (Bifidobacterium longum) along with competitive E. coli bacteria.

E. coli can be found in our gut, and although most strains are harmless, some can cause disease, and they can crowd out beneficial organisms.

Scientists in this study also prepared an identical set of dishes except for the addition of a bacteriophage mixture. After just five hours, the difference was striking.16

In the dishes without the bacteriophages, there was little growth of the desirable B. longum organism, indicating their inability to compete with E. coli. But in the dishes containing the bacteriophages, colonies of B. longum skyrocketed to more than 7,000 times their numbers compared to petri dishes without the bacteriophage. This was a clear demonstration of how the bacteriophage selectively targeted the E. coli, making room for the beneficial bacteria to multiply.16

In a similar study, the beneficial bacteria Lactobacillus acidophilus was grown along with E. coli. As expected, the E. coli greatly suppressed growth of the L. acidophilus.

But when the phage cocktail was added, L. acidophilus thrived, reaching colony counts that were 20-fold higher compared to the culture not receiving the bacteriophages. Similar results were observed when beneficial B. bifidum bacteria were tested.16

Switching gears, scientists tested the capacity of the common prebiotic inulin to stimulate the growth of the beneficial Lactobacillus paracasei. Used alone, inulin failed to ensure the survival of the desired organisms. But using the combination of inulin plus the phage mixture produced an astonishing nine million-fold increase in the growth of the beneficial L. paracasei.16

These initial lab findings demonstrated the value of the phage mixture in promoting the growth and survival of beneficial organisms. Now it was time for scientists to test its potency in live subjects.

Proven Safety Record
Proven Safety Record

Bacteriophages have been successfully used in numerous human clinical and therapeutic settings and have demonstrated an extremely strong safety profile.35-37 The reason for the very safe interaction between phages and human tissue likely results from human exposure to vast numbers of phages over the entire course of evolution. This naturally high human tolerance to bacteriophages contrasts sharply with the risks inherent in compounds that are relatively novel in human evolution—such as drugs.13



Phage Cocktail Validated in Gastrointestinal Environment

Researchers next demonstrated the effectiveness—and safety—of a phage cocktail when used in the gut of living lab rodents. One group of mice was given the probiotic B. longum along with the disease-causing E. coli strain H10407. The second group received the same mixture but with the addition of a phage cocktail specifically designed to target E. coli.17

After just 24 hours, the phage-treated group experienced a clear reduction in E. coli along with an impressive increase in beneficial B. longum bacteria.

The phage group showed the following effects on E. coli:

  • 10-fold decrease of E. coli in the small intestine;
  • 100-fold decrease of E. coli in the large intestine;
  • 100-fold decrease of E. coli in fecal matter.

The phage subjects showed the following approximate effects for B. longum:

  • 100-fold increase of B. longum in the small intestine;
  • 100-fold increase of B. longum in the large intestine;
  • 40-fold increase of B. longum in fecal matter.

The phage-treated group had improved digestive function and no detrimental changes, establishing overall safety and benefit.

By contrast, mice treated with only E. coli and B. longum—without the added phage cocktail—became constipated with intestinal segments showing swelling, redness, and leaks compared with healthy animals.

With so much scientific investigation into the multiple health benefits of a balanced microbiome, phage therapy is rapidly emerging as a new method of enhancing the benefits of probiotics.

Superior Delivery System

Scientists have developed a powerful combination of six probiotic strains and four phages. But as beneficial as these six probiotics are, they have to be able to reach the intestines in order to work—and that requires remaining intact as they pass through the harsh, acidic environment in the stomach. This environment can limit the number of live microbes that reach their destination and, in turn, limit their beneficial effects.

A dual-encapsulation technology overcomes this problem by providing a capsule-within-a-capsule. The outer capsule contains the phages. The inner capsule contains the probiotic and remains intact longer to ensure that these bacteria reach the small intestine safely—delivering unprecedented numbers of live microbes to exactly where they are needed. This rebalances your microbiome to improve intestinal health and confers resistance to the bacterial imbalances that are associated with so many of the chronic degenerative diseases of aging.


Our gut microbiome greatly affects your immune system and overall health.

Probiotics have become popular to help balance intestinal flora.

Taking bacteriophages along with a probiotic selectively kills undesirable bacteria, making way for the good bacteria to survive and thrive.

When probiotics are accompanied by targeted phage therapy, beneficial bacteria multiply massively thanks to the removal of competing, unhealthy microbes.

Phage therapy shows promise in relieving the functional changes caused by gut microbiome imbalance. These may be especially valuable for aging individuals.

If you have any questions on the scientific content of this article, please call a Life Extension® Wellness Specialist at 1-866-864-3027.


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