Using Fermented Food To Reset The Gut Microbiome

Fasting and fermented foods have become two of the most popular trends in health, food, and wellness over the last few years. We say “trends” but in fact, both have been with us for thousands of years. 

Throughout history, societies have dealt with famine. This has meant extended fasting as well as intermittent fasting. Particularly in agrarian communities, enforced periods without food has been the result of the failure of crops due to disease or pestilence, as well as the inability to grow crops in the colder months. This is particularly so in the cooler parts of the world.

Fasting by choice has also played a key role in many religions of the world. 

The link between fasting and fermented foods is also clear. Fermented foods such as sauerkraut and kimchi were originally produced to store food in the cooler months, to provide sustenance in winter.

But are they linked in another way? Can fermented foods help to repopulate the gut with beneficial bacteria after long-term fasting? 

We hope to find out more in this two-part series.

In the first part, we’ll look at what intermittent and longer-term fasting are and how it relates to the gut microbiome. 

In the second, we’ll examine how re-populating the gut with fermented foods such as sauerkraut is the best way to repopulate the gut with beneficial bacteria when the fast is over.

Intermittent fasting

Very much in vogue, supporters of intermittent fasting have claimed its many health benefits. This includes weight loss, mental clarity, improving gut health, even boosting longevity. 

There are many types of intermittent fasting. Most are usually described according to the calorific restriction and the time this is reduced. For example, is referred to as the 16/8 diet. This means the person on the diet fasts for 16 hours and takes their meals during a selected eight-hour period. 

There are also alternative day fasts, the more restrictive 20/4 diet and many more. A Harvard University health article suggests the timing of the intermittent fasting schedule is crucial. 

But what does the science say?

While reports are inconclusive, and more research is needed, there is some tentative scientific backing for these claims.

The Food and Mood Centre, part of Deakin University is currently conducting a study that will investigate the link between intermittent fasting and Chronic Heart Failure (CHF).

According to the Centre, animal studies have shown a reversal of damage caused by heart disease.

“In rat models of CHF, 6 weeks of IF on alternate days reduced body weight and successfully reversed cardiovascular damage. Relative risk of death was reduced by 84%,” it said in an article on the centre’s website.

The new research is designed to examine whether intermittent fasting can be good for the health of humans. 

Much of the interest in research on intermittent fasting has been on whether it can help us lose weight, one of the fundamental health problems of our time. A 2021 study on mice by the University of Sydney, found that while belly fat undergoes “...dramatic changes during intermittent fasting”, some visceral fat becomes resistant to intermittent diets.

“This suggests the visceral fat can adapt to repeated fasting bouts and protect its energy store,” said Dr Mark Larance from the university’s Charles Perkins Centre.

“This type of adaptation may be the reason why visceral fat can be resistant to weight loss after long periods of dieting.”

Longer-term fasting and gut health

This has been with us for centuries, with longer-term fasting often described as abstinence or doing without much (or any) food for a specific period. Examples of such prolonged fasting are usually seen in religious contexts — used as ritual abstinence — or for more long-term health goals.

However, studies in mice have also shown prolonged fasting may cause some changes in gut microbiota. As the digestive tract is used less, it may remodel the gut’s structure, according to studies. 

But what of gut health? Does fasting boost the friendly gut microbes in any significant way? Next week we’ll take a closer look at the effects of, particularly, longer-term fasting on gut health. We’ll examine how repopulating the gut with fermented foods such as sauerkraut may be one of the quickest ways to restore balance in the gut microbiome.

Join us next week when we go into the restructuring of the gut during prolonged fasts in more detail. We’ll also look at the role eating fermented foods, such as sauerkraut, helps re-populate the gut when the fast is over.

As always, we at Gutsy Ferments recommend you consult your health and nutrition professional before starting any diet.