Fermented Foods Gaining Popularity as Health Benefits Become More Widely Recognized

fermenting foods

Story at-a-glance

  • I recommend eating two kinds of food every day; fermented and fiber-rich foods, to help optimize gut flora and your overall health.
  • Many people are getting weary of processed fare and the dubious health claims that go with it, and are embracing more traditional foods and relearning ancient culinary methods such as fermenting
  • Bacteria convert sugars and starch into lactic acid, a process called lactofermentation. Fermented foods help improve your gut health by “reseeding” your gut with beneficial bacteria
  • The fermentation process also boosts the nutritional content of the food, producing essential amino acids, short-chained fatty acids, beneficial enzymes, certain nutrients and increases bioavailability of minerals


This is an older article that may not reflect Dr. Mercola’s current view on this topic. Use our search engine to find Dr. Mercola’s latest position on any health topic.

By Dr. Mercola

As noted by Epoch Times,1 consumer behavior is changing in regard to food. Many are getting weary of processed fare and the dubious health claims that go with them, and are embracing more traditional foods and relearning ancient culinary methods such as fermenting.2 According to the featured article:3

"This change in our relationship with food can be explained by the rise of 'diets of enlightenment.'

In his book 'The Omnivorous Mind: Our Evolving Relationship With Food,' author John S. Allen,[Ph.D.], looks at how certain consumers are ... focusing more on holism, emotion, personal opinion and experience when it comes to their food ...

[P]ersonal paths to enlightenment are leading shoppers to shun the 'marketi[z]ed science' of the food industry, in favor of homemade, experiential, and locally sourced options ...

A significant number of people now seem to be choosing their approaches to eating for reasons less to do with nutrition and more to do with wellness, sustainability and the search for identity. So goes the saying, you are what you eat."

Your Body Is a Conglomerate of Microorganisms

In more recent years, scientists have discovered just how important your microbiome is for health.

Indeed, some have suggested your body can best be viewed as a "super organism" composed of a diverse array of symbiotic microorganisms that need to be kept in proper balance for optimal physical and psychological functioning.

You have approximately 1,000 different species of bacteria living in your body, and these bacteria actually outnumber your body's cells by 10 to 1. You also harbor viruses (bacteriophages), and they in turn outnumber bacteria 10 to 1.

They've even realized your microbiome is one of the environmental factors that drive genetic expression, turning genes on and off depending on which microbes are present.

Research suggests many are deficient in beneficial gut bacteria, making it a very important consideration if you're not feeling well, physically or psychologically.

Why Ferment Foods?

Bacteria and yeast are both used in food fermentation, which boosts the nutritional content of the food. Bacteria convert sugars and starch into lactic acid, a process called lacto-fermentation, whereas yeasts undergo ethanol fermentation.

Beer and wine are examples of the latter and, while fermented, their influence on health is less beneficial compared to lacto-fermented foods like yogurt, cheese and fermented vegetables, primarily due to their alcohol content.

While you can do wild fermentation (allowing whatever is naturally on the vegetable to take hold), this method is more time consuming, and the end product less certain.

Inoculating the food with a starter culture speeds up the fermentation process and helps to ensure you'll end up with a consistent, high-quality end product. Besides preserving the food, allowing it to be stored for several weeks without the addition of preservatives, the fermentation process also produces:

  • Beneficial healthy bacteria that promote gut health. Fermented milk products also contain non-digestible carbohydrate galacto-oligosaccharide, which acts as a prebiotic,4 and essential amino acids5
  • Beneficial enzymes
  • Certain nutrients, including B vitamins, biotin and folic acid.6 Fermented milk products also contain higher amounts of conjugated linoleic acid (CLA)7
  • Increased bioavailability of minerals8
  • Short-chain fatty acids, which help improve your immune system function

Most Stand to Benefit From Fermented Foods

In my view, optimizing your gut health is a foundational step if you are seeking to achieve good health. Addressing your gut flora is also important for most health conditions, be they acute or chronic.

Considering current disease statistics, it seems clear that most people have poor gut health and would benefit from eating more fermented foods. While you could certainly use a high-quality probiotic supplement, eating fermented foods is, I believe, a more effective and far less expensive option.

Since different fermented foods will contain disparate bacteria, your best bet is to eat a variety of fermented foods to optimize microbial diversity.

Fiber serves as a prebiotic and is another important component, and may even take precedence if you're already healthy, as fiber-rich foods provide nourishment for the beneficial microbes already residing in your gut.

By strengthening their numbers, these beneficial microbes help keep disease-causing microbes in check.

I recommend eating fermented and fiber-rich foods every day, as research shows your microbiome can be very rapidly altered based on factors such as diet, lifestyle and chemical exposures.

This is a double-edged sword, no doubt, considering how many of our modern conveniences (such as processed foods, antibiotics and pesticides) turn out to be extremely detrimental to our gut flora.

On the other hand, your diet is one of the easiest, fastest and most effective ways to improve and optimize your microbiome, so the good news is that you have a great degree of control over your health destiny.

Do Bacteria in Fermented Foods Survive Your Digestive System?

Lucy Shewell, Ph.D., a molecular microbiology research scientist, has written some well-referenced articles about fermented foods, covering their nutritional makeup, health benefits and evidence showing many do in fact survive the treacherous journey through your gastrointestinal (GI) tract.9,10 According to Shewell:11

"Large cohort studies conducted in the Netherlands, Sweden and Denmark found that fermented milk products were significantly associated with decreased disease states.

These disease states include bladder cancer, cardiovascular disease and periodontitis ... Bacteria derived from food appear to be members of the variable human microbiome with the ability to alter the gut microbiome.

But do the bacteria we ingest in common fermented foods ... actually survive once we eat them? ...

The stomach is an extremely acidic environment (pH < 3) and contains destructive digestive enzymes, such as pepsin, which break down proteins into smaller amino acid building blocks.

Most ingested bacteria will not survive this first part of the journey ... [T]hey must also be able to adhere to the gut epithelial cells in order to have any beneficial effects.

Variation in the ability of probiotic strains to survive the human GI tract has been demonstrated. Studies subjecting various strains to conditions simulating the environment of the human GI tract found that strains of B. animalis, L. casei, L. rhamnosus and L. plantarum have the greatest resilience."

Research has also demonstrated that the Lactobacillus strain, found in yogurt for example, survives the human GI tract, provided the bacteria are present in the food in sufficiently high numbers.

The lactic acid bacteria found in kimchi have also been found to survive the journey through your digestive system. To be effective, research suggests dosages of 100 million to 1 billion colony-forming units (CFUs) are needed.12,13,14,15

How Probiotics Influence Your Health and Well-Being

Each of Shewell's articles contains at least 80 scientific references, so if you really want to delve into the science of fermented foods, I suggest reviewing them. In summary, research shows fermented foods, be it cultured dairy or fermented vegetables, have a wide range of beneficial effects, including the following:

Enhanced nutritional content of the food

Restoration of normal gut flora when taking antibiotics

Immune system enhancement

Improvement of symptoms of lactose intolerance

Reduced risk of infection from pathogenic microorganisms

Weight loss aid. Certain fermented foods, such as kimchi, have been shown to have anti-obesity effects in animals

Reduced constipation or diarrhea and improvement of inflammatory bowel conditions such as Crohn's disease, ulcerative colitis, irritable bowel syndrome (IBS) and necrotizing enterocolitis

Prevention of allergies in children, including the alleviation of peanut allergy when giving probiotics in conjunction with oral immunotherapy16

Antioxidant17 and detoxifying effects (kimchi).

Kombucha also has antioxidant properties, thanks to a compound called D-saccharic acid-1,4-lactone (DSL)18

Reduced risk for Helicobacter pylori (H. pylori) bacterial infection, which causes ulcers and chronic stomach inflammation

Improvement of leaky gut (a compromised intestinal wall that allows undigested foods and toxins to pass into the bloodstream, triggering an inappropriate immune system response)

Reduced urinary and female genital tract infections

Improvement of premenstrual syndrome

Improvement of and reduced risk for atopic dermatitis (eczema) and acne

Reduced risk for type 1 diabetes and type 2 diabetes19

Improved mental health, mood control and behavior

Improvement of autistic symptoms20,21

Reduced risk of brain diseases, including Alzheimer's

Fermenting Your Own Veggies Is Easy and Inexpensive

I recommend inoculating the food you're about to ferment using a starter culture to speed up the fermentation process. In the video above, Julie and I demonstrate how to make fermented vegetables at home.

You can find more advice on fermentation in my previous interview with Caroline Barringer, a Nutritional Therapy Practitioner (NTP), and an expert in the preparation of the foods prescribed in Dr. Natasha Campbell-McBride's Gut and Psychology Syndrome (GAPS) Nutritional Program. For a simple kimchi recipe, see Shewell's blog.22 Here's a summary of the basics:

  • Shred and cut your chosen veggies. I strongly recommend using fresh organic vegetables to avoid pesticide exposure. Also, when adding herbs, only use fresh organic herbs, in small amounts. Tasty additions include basil, sage, rosemary, thyme and oregano.
  • Juice some celery. This is used as the brine, as it contains natural sodium and keeps the vegetables anaerobic. This eliminates the need for sea salt, which prevents growth of pathogenic bacteria.
  • Pack the veggies and celery juice along with the inoculants into a 32-ounce wide-mouthed canning jar. Starter culture, such as kefir grains, whey or commercial starter powder can all be used for vegetables. Use two packets of starter culture for a 12- to 14-jar batch during summer season. In the winter, you'll need three packets for a batch of this size. A kraut pounder tool can be helpful to pack the jar and eliminate any air pockets.
  • Top with a cabbage leaf, tucking it down the sides. Make sure the veggies are completely covered with celery juice and that the juice is all the way to the top of the jar to eliminate trapped air.
  • Seal the jar and store in a warm, slightly moist place for 24 to 96 hours, depending on the food being cultured. Ideal temperature range is 68 to 75 degrees Fahrenheit; 85 degrees max. Remember, heat kills the microbes!
  • When done, store in the refrigerator to slow down the fermentation process.

While some fermented foods contain vitamin K2, most notably natto, a fermented soy product typically sold in Asian grocery stores, you can create therapeutic levels of this vitamin in fermented vegetables by using a special starter culture made with vitamin K2-producing bacteria.

(Please note that not every strain of bacteria makes K2, so not all fermented foods will contain it. For example, most yogurts have almost no vitamin K2. Certain types of cheeses, such as Gouda, Brie and Edam are high in vitamin K2, while other cheeses are not.)

Our Kinetic Culture Jar Lids Help Cut Offensive Fermenting Odors

Besides a starter culture, other helpful tools include a shredding disc, a kraut pounder/vegetable tamper tool, weights and kinetic culture jar lids. Some people find the odor emitted by fermenting vegetables objectionable, and the kinetic culture jar lids can help eliminate these smells.

The lid has a one-way valve that allows the gases to be released while preventing oxygen from entering the jar, which would stop the fermentation process. A charcoal filter cuts the odors. Again, they're by no means necessary, but can be useful if you or one of your family members isn't thrilled with the smell of fermenting vegetables.

Optimizing Your Microbiome Is a Potent Disease Prevention Strategy

I believe optimizing your gut flora may be one of the most important things you can do for your health, and here you can wield your personal power to the fullest by making healthy food and medical choices. The good news is that supporting your microbiome isn't very complicated. One of the best ways to improve your gut health is through your diet. Fermented foods are ideal, but dietary fiber is also important. Some microbes ferment fiber and the byproducts nourish your colon.

You'd also be wise to take other proactive steps to support your gut health and prevent damage to your microbiome. To optimize your microbiome, consider the following recommendations:

Do: Avoid:

Eat plenty of fermented foods. Healthy choices include lassi, fermented grass-fed organic milk such as kefir, natto (fermented soy) and fermented vegetables.

If you ferment your own, consider using a special starter culture that has been optimized with bacterial strains that produce high levels of vitamin K2.

This is an inexpensive way to optimize your vitamin K2, which is particularly important if you're taking a vitamin D3 supplement.

Antibiotics, unless absolutely necessary (and when you do, make sure to reseed your gut with fermented foods).

While researchers are looking into methods that might help ameliorate the destruction of beneficial bacteria by antibiotics,23,24 your best bet is likely always going to be reseeding your gut with probiotics from fermented and cultured foods.

Boost your soluble and insoluble fiber intake, focusing on vegetables, nuts and seeds, including sprouted seeds.

Conventionally-raised meats and other animal products, as animals raised in concentrated animal feeding operations (CAFOs) are routinely fed low-dose antibiotics, plus genetically engineered grains loaded with glyphosate, which is widely known to kill many bacteria.

Get your hands dirty in the garden. Germ-free living may not be in your best interest, as the loss of healthy bacteria can have wide-ranging influence on your mental, emotional and physical health.

Exposure to bacteria and viruses can help strengthen your immune system and provide long-lasting immunity against disease.

Getting your hands dirty in the garden can help reacquaint your immune system with beneficial microorganisms on the plants and in the soil.

According to a recent report,25 lack of exposure to the outdoors can in and of itself cause your microbiome to become "deficient."

Chlorinated and/or fluoridated water, especially in your bathing such as showers, which are worse than drinking it.

Open your windows. For the vast majority of human history the outside was always part of the inside, and at no moment during our day were we ever really separated from nature. Today, we spend 90 percent of our lives indoors.

And, although keeping the outside out does have its advantages it has also changed the microbiome of your home.

Research27 shows that opening a window and increasing natural airflow can improve the diversity and health of the microbes in your home, which in turn benefit you.

Processed foods. Excessive sugars, along with otherwise "dead" nutrients, feed pathogenic bacteria.

Food emulsifiers such as polysorbate 80, lecithin, carrageenan, polyglycerols, and xanthan gum also appear to have an adverse effect on your gut flora.26

Unless 100 percent organic, they may also contain genetically engineered (GE) ingredients that tend to be heavily contaminated with pesticides such as glyphosate, a possibly carcinogenic pesticide.

Wash your dishes by hand instead of in the dishwasher. Research has shown that washing your dishes by hand leaves more bacteria on the dishes than dishwashers do, and that eating off these less-than-sterile dishes may actually decrease your risk of allergies by stimulating your immune system.

Agricultural chemicals. Glyphosate (Roundup) in particular is a known antibiotic and will actively kill many of your beneficial gut microbes if you eat and foods contaminated with this broad-spectrum herbicide.

Antibacterial soap, as they too kill off both good and bad bacteria, and contribute to the development of antibiotic resistance.


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