Aug 042012

Fasting represents voluntary abstaining from some or all foods for varying lengths of time and is used as therapy for many chronic conditions. Could it be useful for leaky gut? There are several studies confirming reduced intestinal permeability resulting from caloric restriction or fasting.

Influence of Fasting on Intestinal Permeability and Disease Activity in Patients with Rheumatoid Arthritis

We have investigated the influence of fasting and lactovegetarian diet on intestinal and non-intestinal permeability in 5 patients with rheumatoid arthritis.

Both intestinal and non-intestinal permeability decreased after fasting, but increased again during a subsequent lactovegetarian diet regime. Concomitantly it appeared that disease activity, as shown by a clinical six-joint score, first decreased and then increased again. The results indicate that, unlike lactovegetarian diet, fasting may ameliorate the disease activity and reduce both the intestinal and the non-intestinal permeability in rheumatoid arthritis.

Intestinal permeability is decreased in anorexia nervosa found significantly decreased intestinal permeability (situation opposite to leaky gut) in 17 anorexic woman compared to healthy controls.

In this paper Fasting, intestinal permeability, and rheumatoid arthritis i tis concluded that:

Otherwise healthy and well-nourished patients with rheumatoid arthritis show significant clinical improvement from practicing prolonged fasting for 7 to 10 days. The improvement is reversible and lost when eating is taken up again. Although of little therapeutic value, the anti-inflammatory effect of short-term fasting is of significant interest and better understanding of the mechanisms is desirable.


We do however need to distinguish between fasting in situation when the body is receiving all important nutrients outside of the fasting period and malnutrition when one or more nutrients is missing as these two studies are showing:

Gut barrier function in malnourished patients

There was a significant increase in intestinal permeability in the malnourished patients

Intestinal transport during fasting and malnutrition

Fasting or malnutrition (FM) has dramatic effects on small intestinal mucosal structure and transport function. Intestinal secretion of ions and fluid is increased by FM both under basal conditions and in response to secretory agonists. Intestinal permeability to ions and macromolecules may also be elevated by FM

I do believe deficiency of certain vitamins and minerals can play significant role in leaky gut and I will be looking at nutrients that are necessary for curing leaky gut in future posts.

There is several possible ways to perform the fast

1. full day fast (that is 36 hours including two nights)

2. regular intermittent fasting the Leangains way

3. random skipping of meals

Good guide can be found at Mark Sisson’s site

The full day fast can specifically be useful if you are unsure of your leaky gut diagnosis: if your symptoms reduce significantly after the one day fast than it is likely the food you are eating that is harming you. This is how I found I was gluten sensitive: after eating very little for two days due to flu infection my rash was suddenly gone and came back when I started to eat.

The fasting can also be useful in case of dietary mistake of eating substances that promote leaky gut (alcohol, coffee …) or cross the permeable barrier and trigger reaction (gluten, casein …). In that case fasting not only increases intestinal permeability (reduces leaky gut) but also stops the flow of food that can contain substances getting the condition worse. Our gut needs break, we have not evolved to the constant supply of foods we are getting, fasting is by far more common in the nature than we see it in our everyday life.

Whenever fasting stay well hydrated whether you are suffering from leaky gut or not.

Happy fasting!


photo credit: RLHyde via photo pin cc

  One Response to “Fasting and leaky gut syndrome”

Comments (1)
  1. Great research and thanks for simplifying it! There’s this guy who did a 16 days straight water fast and successfully healed his eczema, but like you said his symptoms should have worsened because of nutritional deficiency… I don’t know.. just worthy to be mentioned:

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