How Fasting Helps Intestinal Stem Cells Regenerate

Bullet Proof Coffee: An Intermittent Fasting Favorite Breakfast
MIT Research on Fasting:
Why Fasting Can Improve Your Gut Health

There was a link to an interesting research paper on water fasting posted over at the Celiac subreddit this morning.

Although, such research studies are almost always pharmaceutical focused, and this particular study by MIT biologists was no exception, the results that the researchers observed strongly support the driving mechanisms of both low-carb diets and fasting.

For a long time, it's been well known within the scientific community that low-calorie diets have a strong impact on longevity. Because of this, Omer Yilmaz (an MIT assistant professor of biology and member of the Koch Institute for Integrative Cancer Research) and colleagues wanted to explore how fasting affects intestinal stem cells.

As we age, intestinal stem cells begin to lose their ability to regenerate, and since these stem cells are responsible for dividing themselves, and thereby, creating new stem cells to govern repairs, any decline in regeneration will affect the intestine's ability to heal itself from infections and physical damage.

Stem cells maintain the lining of the intestine and are the source of new intestinal cells, so aging can affect your ability to recover from:
  • celiac disease
  • inflammatory bowel diseases
  • intestinal infections
  • leaky gut
  • and even cancer
Basically, anything that affects the lining, villi, and crypts of the intestines is directly related to the health of your intestinal stem cells, and their ability to regenerate.

Included in this would also be intestinal inflammation brought about by food sensitivities and other autoimmune diseases. Chronic inflammation adversely affects the intestine's ability to absorb nutrients, which in turn, can affect weight loss.

The findings of the study are of particular interest to those on ketogenic diets, as well as those using fasting protocols in their nutritional approaches. Results are not just applicable to those with intestinal diseases or food sensitivities, though.

The magnitude of the findings are far more reaching than that, so here is what the study means for those doing fasting or Keto.

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What Did the Research on Fasting Show?

The MIT biologists took young and old mice and fasted them for a 24 hour period. They next removed some stem cells from the intestines and observed the rate at which the cells started to reproduce themselves.

The scientists were astounded to see that the rate of reproduction had actually DOUBLED after that one 24-hour fast.

And it didn't matter how old the mice were.

Both young and old mice had the exact same ability to double their stem-cell regeneration.

For those using Intermittent Fasting or a Water Fast protocol along with a ketogenic diet, this part of the study was very encouraging. Fasting for even a 24 hour period has dramatic effects on the intestine's ability to heal itself from inflammation, infection, and physical damage.

For those with celiac disease and other inflammatory intestinal conditions, this is huge, since accidental exposure to gluten produces inflammation and damage to the villi that line the intestine. But it is just as important for those with food allergies, sensitivities, and other systemic inflammatory conditions.

Regular fasting can improve your intestinal stem cell's ability to regenerate and heal the gut.

Why Did Intestinal Stem Cells Double Their Ability to Regenerate?

Fasting drains your glycogen stores and triggers the state of ketosis.

The research paper didn't use the word "ketosis," but it did clearly state that the reason for the increase in regeneration came from the fact that fasting forces the body to switch from burning glucose for fuel to oxidizing fatty acids instead. Something that doesn't necessarily happen on low-calorie diets unless they are also low in carbs.

And it was using fatty acids for fuel, instead of glucose, that triggered the stem cell's ability to regenerate themselves.

This was done by activating transcription factors known as PPARs, which turn on genes that are involved in metabolizing fatty acids. When you eat more fat or want the body to metabolize more fat, the body turns on genes that are responsible for producing the enzymes that make it possible to do that.

When the PPAR pathway was blocked by the biologists, fasting had NO effect on the regeneration of intestinal stem cells. There was no boost in stem cell production.

This supports my own view that those who don't do well on low-carb diets are having genetic trouble cranking up the enzymes needed to burn all of the extra fat.

Switching from glucose to fatty acids dramatically increased the function of intestinal stem cells at the molecular level.

In other words, stem cells work better on a fat-burning metabolism than they do on a glucose-burning metabolism. Regeneration of your intestinal lining, which includes the villi and crypts, is greatly enhanced when you switch from a high-carb diet to one that supports fat burning, such as Keto.

Typically, the intestinal lining renews itself every 5 days, so keeping stem cells working more efficiently can greatly improve your quality of life. Both fasting and Keto can help you do this.

However, anything that refills your glycogen stores will interfere with the regeneration process. This is probably why occasional fasting can help you clear out the glycogen and get your body back to seriously burning fats again.

As regenerative capacity declines, it takes longer and longer for the intestines to heal after an injury or infection. It is to your advantage to keep the stem cells as healthy as possible because stem cells are also responsible for all of the other intestinal cell types and not just additional stem cells.

This would affect the tightness of your intestinal junctions, as well as intestinal mobility and ability to absorb the nutrients from your food.

Benefit of Fasting on Keto

You can't ignore nutrition at the expense of metabolism. While the study showed that a metabolic change in the way stem cells function changed their behavior, and future studies intend on looking into how fasting affects other body tissues, nutrition is just as important to help heal leaky gut, celiac disease, intestinal flu, and even cancer.

The study only looked at the effects of water fasting for a 24 hour period in mice, but we know that nutrient-rich ketogenic diets also force the body to switch metabolic pathways, trigger fat-burning genes, and cause the body to go into fat-burning mode -- just as fasting does.

This makes Keto as important as fasting for longevity and health.

Whether Keto and fasting are comparable in degree, the study doesn't show. But in my experience, it is easy to refill your glycogen stores even on Keto.

Bingeing on low-carb foods is common among low carbers who think overeating low-carb foods is a superior technique to overeating carbs. However, Keto-friendly foods, such as meat, vegetables, and alternative flours will refill glycogen stores the same as sneaking a chocolate chip cookie will.

Especially, if you're doing a lot of low-carb baking or eating sweets.

This is because both excess protein and excess carbs refill your glycogen stores. There is honestly no difference between the carbs in low-carb foods and those in high-carb foods.

Carbs are carbs.

The carbs in low-carb foods can add up to a hefty carb load by the end of a binge.

In addition, if you're getting hidden carbs or suffering from carb creep, due to not counting your carbs, glycogen stores are most likely partially refilled at best.

There is nothing wrong with doing Lazy Keto, but it can adversely affect your intestinal stem cells if the carbs accumulate and creep up too high.

Occasional fasting or going very low carb for a few days can be very beneficial in clearing out any partially refilled glycogen stores. This will get you back into the nutritional ketosis zone, if you accidentally fell out, as well as trigger your intestinal stem cells to act more efficiently again.


MIT News, "Fasting Boosts Stem Cells' Regenerative Capacity," Anne Trafton, May 3, 2018