Antibiotic-Resistant Genes in Cow Manure May Add to the Threat of Untreatable Disease


Story at-a-glance -

  • Maintaining optimal intestinal health is paramount in the fight against both acute and chronic disease. One of the fastest ways to destroy your gut microbiome is through the use of antibiotics
  • While antibiotics are certainly overused in medicine, one of the most pervasive sources of antibiotics is actually through the foods you eat—in particular factory farmed meats
  • Recent research has found antibiotic-resistant genes in the bacteria of dairy cows' guts. Cow manure, commonly used as crop fertilizer, may transfer these bacteria to soil where food is grown for human consumption
  • 80 different antibiotic-resistant genes were found in five manure samples. When these genes were added to E.coli bacteria, the E.coli became resistant to antibiotics
  • Traditionally fermented (unpasteurized) foods are the best route to optimal digestive health

By Dr. Mercola

Your immune defenses are key in protecting you from all disease, including cancer, toxic poisons, infections, inflammation, and even the ravages of aging. What many fail to realize is that your immune system actually begins in your gut, and that maintaining optimal intestinal health is paramount in the fight against both acute and chronic disease.

Your gastrointestinal tract, where 80 percent of your immune system resides, houses some 100 trillion bacteria—about two to three pounds worth. These bacteria actually outnumber your body's cells by about 10 to one, and are instrumental for a wide variety of bodily functions.

One of the fastest ways to destroy your gut microbiome is through the use of antibiotics, which does not discriminate between pathogenic and beneficial bacteria.

Every time you swallow antibiotics, you kill some of the beneficial bacteria in your intestines, upsetting the delicate balance of your intestinal terrain.

Besides allowing for the overgrowth of pathogenic microorganisms, this can also lead to a syndrome called "leaky gut syndrome" whereby your intestinal wall is damaged, interfering with how your body absorbs nutrients and filters out waste and toxins, thereby exacerbating a wide variety of diseases, including autoimmune disorders.

CAFOs Raise Antibiotic-Resistant Bacteria

While antibiotics are certainly overused in medicine, one of the most pervasive sources of antibiotics is actually through the foods you eat—in particular factory farmed meats.

Animals raised in so-called confined animal feeding operations (CAFOs) are routinely fed antibiotics to promote growth. Agricultural uses of antibiotics actually account for about 80 percent of all antibiotic use in the US,1 so it's undoubtedly a major source of human antibiotic consumption.

When animals are fed low doses of antibiotics on a daily basis, it disrupts their natural microbiome, allowing stronger, more antibiotic-resistant bacteria to survive, multiply, and pass on their strength and resistance to future generations. There's little doubt that agricultural use of antibiotics for non-medical use is one, if not the primary driver of antibiotic-resistant disease.

According to the US Centers for Disease Control and Prevention2 (CDC), two million American adults and children become infected with antibiotic-resistant bacteria each year, and at least 23,000 of them die as a direct result. The CDC has previously concluded that as much as 22 percent of antibiotic-resistant illness in humans is in fact linked to food, and research has shown that nearly half of all meats sold in the US harbor drug-resistant bacteria!

Genes That Confer Antibiotic-Resistance Found in Cow Manure

Contaminated meat is not the only culprit in the food supply, however. Since feces from animals raised in CAFOs are used as fertilizer on crop fields, antibiotic-resistant disease may even be promulgated via the soil in which vegetables, fruits and grains are grown. As recently reported by Medical News Today:3

"Previously unidentified antibiotic resistance genes have been discovered in the bacteria of dairy cows' guts. Commonly used as a farm soil fertilizer, cow manure could aid in transferring this bacteria to soil where food is grown for human consumption."

The study in question, published in mBio,4, 5, 6 found 80 different antibiotic-resistant genes in five manure samples. Researchers still do not know the impact such genes might have for human health, but there are disturbing implications. When the researchers added these genes to a laboratory strain of the E.coli bacteria, it became resistant to four different antibiotics normally used to treat the infection.

Eating organically may not entirely alleviate this particular problem, since organic crops, which cannot be fertilized with synthetic fertilizers, are the ones most often fertilized with manure. As it stands, manure that contains antibiotics is still allowed under the organic label. So it all depends on where the organic farmer gets his manure from.

Some organic crop farmers may be getting their manure from organic cattle farms, but there's no guarantee that's taking place. The only way to find out is to ask the farmer first-hand. Taking all of these factors into consideration, is it any wonder that the ratio of good-bacteria-to-bad is upside down in most people in our society?

Non-Human Uses of Antibiotics Have Little to No Value

According to a 2013 paper titled "Preserving Antibiotics, Rationally,"7, 8 non-human use of antibiotics has virtually no value whatsoever. Truly, when you consider the big scheme of things—especially the risks to human health—it's difficult to rationalize agricultural non-medical use of antibiotics.

And yet all the US Food and Drug Administration (FDA) has done about it is ask drug companies to voluntarily restrict the use of antibiotics that are important in human medicine by excluding growth promotion in animals as a listed use on the drug label. Clearly, this does not go far enough to protect human health. As stated by lead author Aidan Hollis, PhD:9

"'Modern medicine relies on antibiotics to kill off bacterial infections. This is incredibly important. Without effective antibiotics, any surgery – even minor ones – will become extremely risky... If you become infected with resistant bacteria, antibiotics won't provide any relief.' While the vast majority of antibiotic use has gone towards increasing productivity in agriculture, Hollis asserts that most of these applications are of 'low value.'

"It's about increasing the efficiency of food so you can reduce the amount of grain you feed the cattle. It's about giving antibiotics to baby chicks because it reduces the likelihood that they're going to get sick when you cram them together in unsanitary conditions. These methods are obviously profitable to the farmers, but... the profitability is usually quite marginal. The real value of antibiotics is saving people from dying. Everything else is trivial." [Emphasis mine]

Is 'Antibiotic Winter' Upon Us?

A recent opinion piece published by CNN, written by Dr. Martin J. Blaser, director of the Human Microbiome Program at New York University and author of the book, Missing Microbes: How the Overuse of Antibiotics is Fueling Our Modern Plagues, issues stern warnings about what's in store if we do not stem the tide of antibiotic-resistant bacteria. He writes, in part:

"...antibiotic use over the years has been depleting the pool of our friendly bacteria -- in each of us -- and this is lowering our resistance to infections. In today's hyperconnected globe, that means that we are at high risk of future plagues that could spread without natural boundaries from person to person and that we could not stop. I call this 'antibiotic winter.'

To explain: In the early 1950s, scientists conducted experiments to determine whether our resident microbes... our 'microbiome' -- help in fending off invading bacteria. They fed mice a species of a typical invader, disease-causing salmonella. It took about 100,000 organisms to infect half of the normal mice. But when they first gave mice an antibiotic, which kills both good and bad bacteria, and then several days later gave them salmonella, it took only three organisms to infect them. This isn't a 10 or 20 percent difference; it's a 30,000-fold difference."

This is nothing if not disconcerting... Not only are resistant bacteria multiplying and spreading like wildfire, but the risks are further compounded by the fact that if your gut flora is compromised (and most Americans' are), bacteria numbering in the single digits might have the ability to wreak havoc in your system! As noted by Dr. Blaser:

"We must end the assault on our microbes, by cutting antibiotic use and also such elective practices as unnecessary cesarean sections that bypass the natural order of mothers passing on their bacteria to their babies."

Optimizing Your Gut Flora May Be One of Your Most Important Disease Prevention Strategies

All of this information should really drive home the point that optimizing and maintaining a healthy gut flora is of critical importance. Swapping from CAFO to organic, pastured meats raised without antibiotics may be a crucial piece of the puzzle. Additionally, to help reseed your gut with beneficial bacteria, I strongly suggest:

  • Eating fermented foods. Traditionally fermented (unpasteurized) foods are the best route to optimal digestive health. Some of the beneficial bacteria found in fermented foods are also excellent chelators of heavy metals and pesticides, which will also have a beneficial health effect by reducing your toxic load.
  • Fermented vegetables are an excellent way to supply beneficial bacteria back into our gut. And, unlike some other fermented foods, they tend to be palatable, if not downright delicious, to most people. (As an added bonus, they can also be a great source of vitamin K2 if you ferment your own using the proper starter culture. Vitamin K2 is a vital co-nutrient to both vitamin D and calcium.) Most high-quality probiotic supplements will only supply you with a fraction of the beneficial bacteria found in such homemade fermented veggies, so it's your most economical route to optimal gut health as well.

  • Taking a high-quality probiotic supplement. Although I'm not a major proponent of taking many supplements (as I believe the majority of your nutrients need to come from food), probiotics is an exception if you don't eat fermented foods on a regular basis. In addition to knowing what to add to your diet and lifestyle, it's equally important to know what to avoid, and these include:
Antibiotics, unless absolutely necessary (and when you do, make sure to reseed your gut with fermented foods and/or a probiotic supplement) Conventionally-raised meats and other animal products, as CAFO animals are routinely fed low-dose antibiotics, plus genetically engineered grains, which have also been implicated in the destruction of gut flora Processed foods (as the excessive sugars, along with otherwise "dead" nutrients, feed pathogenic bacteria)
Chlorinated and/or fluoridated water Antibacterial soap Agricultural chemicals, glyphosate (Roundup) in particular

Help Stop the Spread of Antibiotic-Resistant Disease

There are also a number of ways you can help curtail the growth and spread of antibiotic-resistant bacteria. This includes:

  1. Using antibiotics only when absolutely necessary. Not every bacterial infection needs to be treated with a drug. First, as an all-around preventive measure, you'll want to make sure your vitamin D level is optimized year-round, especially during pregnancy, along with vitamin K2. A number of other natural compounds can also help boost your immune system function to help rid you of an infection, including oregano (oil of oregano), garlic, Echinacea, and Manuka honey (for topical application).
  2. Avoiding antibacterial household products. Triclosan, like antibiotics, helps promote antibiotic resistance.
  3. Purchasing organic, antibiotic-free meats and other foods. Reducing the spread of antibiotic-resistant bacteria is a significant reason for making sure you're only eating grass-fed, organically-raised meats and animal products. Besides growing and raising your own, buying your food from responsible, high-quality, sustainable sources is your best bet, and I strongly encourage you to support the small family farms in your area. While the problem of antibiotic resistance really needs to be stemmed through public policy on a nationwide level, the more people who get involved on a personal level to stop unnecessary antibiotic use, the better.
  4. Properly washing your hands to stop the spread of infection. This is also of particular importance after handling meat products.
  5. Use a designated cutting board for raw meat and poultry, and never use this board for other food preparation, such as cutting up vegetables. Color coding your cutting boards is a simple way to distinguish between them. To sanitize your cutting board, be sure to use hot water and detergent.