The Keto Guide to Fermented Food, Part 1

What are fermented foods and why are they good for us?

Article by Mandy Pagano | 06 Dec, 2020

Article originally published on on 1/24/17. It has been lightly edited for re-publication.

Fermented foods and their relation to proper gut health is something you see bandied about a lot in the health and nutrition communities. Study after study has shown that maintaining the right balance of good bacteria in your digestive system makes for good health in general, and can help avert or treat the gamut of digestive problems like chronic constipation, irritable bowels, diverticulitis, etc. and so on. There is even some beginning (and promising!) research on whether good gut bacteria might help boost the effectiveness of cancer treatment.

When the balance of bacteria in your gut is off, not only can it lead to the digestive problems mentioned, but it's also believed to be linked to a whole plethora of health problems like autoimmune conditions, and there is even some research into whether or not it is related to Type 1 diabetes.

Due to the strong role a healthy gut appears to play in the proper functioning of the body, probiotics are the "it" thing right now. So much so that there are now whole sections of the supplement industry devoted to manufacturing and selling probiotic supplements.

Enter Fermentation

There has been a lot of talk about the role that fermented foods can play in healing and maintaining proper bacterial balance in the gut. So what is fermentation anyway?

Good question!

Fermentation is a process by which bacteria or yeast is introduced to a food, juice, or milk product, and then the microorganism in question consumes whatever natural sugar is present in the starting product, usually leaving behind acid or alcohol as waste. Fermentation has been used by humans for thousands of years to preserve food and drink. Some of the fermented foods we are most familiar with are beer, wine, yogurt, and sourdough bread.

For our keto purposes we are going to ignore the alcohols and the bread. While those are technically fermented foods, the bread is out because regardless of the good bacteria it contains, it still has grains and entirely too many carbs to be considered keto friendly. The fermentation of fruit juices and grains via yeast yields alcohol, which can be fun, but isn't really relevant to discussion about good gut bacteria.

Be Good to Your Gut

When we're talking about fermented foods and gut health, what we're really looking to find are specific bacteria, the most common and well-known of which is lactobacillus acidophilus. This type of prokaryote is what we commonly think of as "good" gut bacteria. It's found naturally in the mouth and digestive tracts of both humans and most animals. This particular bacteria feeds off the sugars naturally present in milk products or decaying fruits and vegetables, and then leaves behind lactic acid as a waste product. The lactic acid serves to both preserve the food and to give it that typical sour/tangy taste we associate with foods like yogurt. More importantly, when we eat goods that have been fermented with this and other "good" bacteria, we are giving our gut a digestive aid, as it helps to break down certain types of food in our bodies. It also works to "crowd out" and prevent the growth and colonization of other bacteria that may be harmful to the digestive system.

Other types of helpful probiotic bacteria are as follows:

  1. Bifidobacterium 
    • helps prevent and heal stomach ulcers
  2. Streptococcus thermophilus
    • may relieve nausea, stomach cramping, and prevent or relieve symptoms of lactose intolerance
  3. Bacillus coaguluns
    • not enough testing has been done to prove direct benefit, but it is believed to aid in relieving or preventing diarrhea, and is a potential component of treatment for irritable bowel disease and flare-ups of the disorder

In order to receive any potential health benefits, fermented foods containing any or all of these bacteria should be unpasteurized, as pasteurization kills the bacteria, rendering it useless. Luckily, the process of fermentation itself is a preservative and so the risks of bacterial infection from consuming unpasteurized fermented foods is very low, as long as the food was processed, sealed, and stored properly. It is important to anyone fermenting at home to follow fermenting instructions very closely so as not to omit any steps that prevent the growth of harmful organisms.

Next week, we will take a look at some of the most popular fermented foodstuffs and assess which ones are safe to include in your ketogenic lifestyle.

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