How Intermittent Fasting Can Improve Your Gut Health

There are many reasons to try fasting. After all, our ancestors have been doing it for centuries. However, science is just starting to catch onto all the benefits of intermittent fasting for gut health.

Unfortunately, many people do not realize how their own gut even functions. They are unaware that inside our gut lives millions of microorganisms. These microbes are in charge of a lot of things, including the digestion of food that we consume. Due to this negligence, many people do not take proper care of their gut. Poor gut health is why so many suffer from gastrointestinal issues.

With so many different treatments out there, you might want to know what you can do to naturally bring your body back into balance. Try doing as our ancestors did. Withhold food from your system. Intermittent Fasting for gut health might be what you needed to rebuild gut flora and replenish beneficial bacteria in your gut biome.

What is Intermittent Fasting?

Intermittent fasting, or IF for short, is considered a diet by some but in reality, it’s not. There is no scientific formula to following intermittent fasting. It’s just fasting in between spurts of time.

While that may sound too simple to be true, IF isn’t very complicated. There are no dietary restrictions. The only restriction is when you eat. During the fasting periods, you can only drink water, coffee, or tea with little to no sweetener. During your feeding time, it’s fair game for food.

This may seem too good to be true, yet there are many benefits of Intermittent Fasting. Essentially, you normally eat for a particular amount of time and then fast for the rest. There are many ways in which people go about with this pattern. These are called protocols.

Types of Intermittent Fasting for Gut Health Protocols

What makes intermittent fasting for gut health such a viable lifestyle choice for many is that you can pick and choose from different protocols. From there, you can make these protocols work with your schedule.

No matter the time window you decide for your intermittent fasting protocol, you can make it fit within your daily schedule. Figure out the times that you need the most energy, when you normally eat, and when you can go the longest without eating.

From there, you can try out these three popular intermittent fasting for gut health protocols:

16:8 or 18:6 method (can even be 20:4, etc): This is where you fast for 16 to 20+ hours, and eat for the remaining hours in the day. This is the most common method.

The 5:2 method: In this method, you eat for 5 days, but for two days, you fast. This fasting can include not consuming any calories at all for these days, or have a very low-calorie limit. This limit is usually around 500 calories max.

One Meal A Day (OMAD) method: Probably the least common of the bunch, but gaining popularity. This is where you eat one large meal a day, and then fast for the rest of the time.

These are just a few of the many different ways that people do IF. There are more intense protocols that include 24-hour fasts and Alternate Day Eating. However, these three are the most common intermittent fasting protocols. Now, why should you do intermittent fasting for gut health? Here are some reasons why your gut biome needs a time out from the digestion of food.

Digestion of Food and Microbiome

When it comes to our gut health, what we put into our body affects which microorganisms grow and flourish within your gut. What we eat draws a fine line in the sand between probiotic bacteria and harmful bacteria.

A long-term diet of consuming junk foods causes helpful microorganisms to die off. Beneficial bacteria relies on the nutrition of whole foods, lean proteins, and complex carbohydrates to prosper. As a result, opportunistic microbes will take their place, ultimately throwing your body into disarray [1].

This is why consuming more fermented foods, such as yogurts and Kombucha teas are beneficial to the gut. Without these vital microorganisms, our bodies simply would not be able to function. Or, as Harvard states:

“In a healthy body, pathogenic and symbiotic microbiota coexist without problems. But if there is a disturbance in that balance—brought on by infectious illnesses, certain diets, or the prolonged use of antibiotics or other bacteria-destroying medications—dysbiosis occurs, stopping these normal interactions. As a result, the body may become more susceptible to disease [2].”


Focusing on what we eat and put into our bodies can help us in the long-term to be healthy. In the case of “You can’t say anything nice, don’t say anything at all,” if you can’t eat anything healthy, maybe you shouldn’t eat anything at all. That’s what so beneficial about intermittent fasting for gut health.

No Bored Eating and How to Improve Gut Health Naturally

The thing we have to understand is that we as humans never had 24-hour access to food until very recently. Before this, we ate what was available, and often went long stretches of time without ever eating at all. Not to mention, what they ate was in whole food form and didn’t cause the gastrointestinal distress we all feel today. This is due to the fact that food was not as abundant nor stuffed with additives as it is today.

While food being readily available is convenient for our fast-paced lives, this abundance is a breeding ground for over-consumption.

Present day humans are now eating every couple of hours, if not sooner. This means that our body is in a constant state of digestion, with little rest in-between. It’s like working an 18-hour shift and only getting a five-minute break.

Science on Intermittent Fasting for Gut Health in Animals

Always stuffing our face can overwork our microbiome. Overeating may cause many of the organisms that we take for granted to die off or exponentially grow. Either way, it disrupts the dynamic of our intestinal flora.

There are actually a fair amount of studies that prove this as well. One study on rats found that intermittent fasting was able to restore the microbiome of the rat after just 18 weeks [3]. A study that was done on fruit flies in 2015 even stated that IF can help to make you live longer [4]. It is important to know that these are animal studies. More research needs to be done before a final conclusion is made.

Science on Intermittent Fasting for Gut Health in Humans

While the studies on intermittent fasting for gut health are predominantly conducted on animals, there has been some research done on humans.

There was a 2014 review about if intermittent fasting can help those who suffer from Metabolic Syndrome [5]. The Abstract in this study noted the many benefits of intermittent fasting for gut health, mental wellness, and cellular function.

The meta-analysis noted,

“Chronic fasting extends longevity in part by reprogramming metabolic and stress resistance pathways. In rodents intermittent or periodic fasting protects against diabetes, cancers, heart disease and neurodegeneration, while in humans it helps reduce obesity, hypertension, asthma and rheumatoid arthritis. Thus, fasting has the potential to delay aging and help prevent and treat diseases while minimizing the side effects caused by chronic dietary interventions.

Cell Metab.

Doctors are now becoming more privy to the potential of intermittent fasting for gut health, which can benefit millions of people worldwide.

Improving Gut Bacteria and Weight Loss

Evidence has come to light in recent years which suggests that gut bacteria may play a crucial role in obesity. Studies have shown that people who are overweight and obese often have a smaller amount of a specific type of bacteria in the gut called Bacteroidetes [6].

That is why improving gut bacteria and weight loss go hand-in-hand. To rebuild gut flora that is beneficial to your overall wellness, you should take personalized probiotics supplements.

Combining Intermittent Fasting with Microbiome Testing

At Thryve, we use microbiome testing to determine which intestinal flora is lacking in your gut biome. We then formulate supplements to rebuild gut flora and eliminate harmful bacteria.

While your probiotics are still growing in your gut biome, you need to give them a better chance of survival. This is where intermittent fasting for gut health may be beneficial.

Intermittent fasting has shown to be just as effective as any other form of diet when it comes to weight loss. Not to mention, the analysis Bacteroidetes showed that losing weight naturally increases the presence of this stomach bacteria. Therefore, when you lose weight with IF, you are potentially increasing beneficial bacteria that live in your body. Over time, this may help keep the weight off.

IF, Gut Biome and Reduction of Foodborne Illness

A 2014 study of Salmonella-infected mice, found that IF was able to help them “reset” their gut microbiome [7].

According to the study:

“…the changes following metabolic stress induced by intermittent fasting during food deprivation days increased the resistance to S. Typhimurium infection by triggering intestinal IgA production and presumably, pathogen elimination by phagocytic inflammatory cells.”

Wiley Online Library

By not eating for periods of time, it gives your body a chance to go back to a state of balance. With gut biome balance, your intestinal flora can diversify, and multiply alongside other beneficial bacteria.

Trying Out Intermittent Fasting for Gut Health

IF can be beneficial to our health in a variety of reasons. It can help with replenishing gut bacteria and weight loss. Intermittent fasting may also reduce inflammation and curb over-eating.

While research on adults for intermittent fasting has been promising, there hasn’t been any science done for the elderly or for children. You should always consult a physician anytime you make dietary changes. However, it’s extremely important when dealing with the elderly and the young.

If you are having gastrointestinal issues or you feel as if your gut health is not in balance, try IF. You might be able to help get it back on track.

Thryve Probiotics Gut Health


[1] Conlon, M. A., & Bird, A. R. (2014). The impact of diet and lifestyle on gut microbiota and human health. Nutrients7(1), 17–44. doi:10.3390/nu7010017

[2] “The Microbiome.” The Nutrition Source, 24 Aug. 2017,

[3] Rong, Zu-Hua, et al. “Effect of Intermittent Fasting on Physiology and Gut Microbiota in Presenium Rats.” Nan Fang Yi Ke Da Xue Xue Bao = Journal of Southern Medical University, U.S. National Library of Medicine, 20 Apr. 2016,

[4] Catterson, J. H., Khericha, M., Dyson, M. C., Vincent, A. J., Callard, R., Haveron, S. M., … Partridge, L. (2018). Short-Term, Intermittent Fasting Induces Long-Lasting Gut Health and TOR-Independent Lifespan Extension. Current biology : CB28(11), 1714–1724.e4. doi:10.1016/j.cub.2018.04.015

[5] Longo, V. D., & Mattson, M. P. (2014). Fasting: molecular mechanisms and clinical applications. Cell metabolism19(2), 181–192. doi:10.1016/j.cmet.2013.12.008

[6] Ley, Ruth E, et al. “Microbial Ecology: Human Gut Microbes Associated with Obesity.” Nature, U.S. National Library of Medicine, 21 Dec. 2006,

[7] Campos‐Rodriguez, R., et al. “Intermittent Fasting Promotes Bacterial Clearance and Intestinal IgA Production in Salmonella Typhimurium‐Infected Mice.” Scandinavian Journal of Immunology, John Wiley & Sons, Ltd (10.1111), 20 Apr. 2014,