Is “Leaky Gut” a Myth?

There is a lot of conflicting information about a leaky gut. Some people think it is a serious disease, others disregard it and say it is all made up and it is all in the person’s head. But if you look into the proper scientific term for “Leaky Gut” you will find a lot of research papers on this topic. I decided to find out the exact number of papers published on PubMed (the database of research papers) and found no less than 2,480,000 articles. Yes, you read it correctly – over TWO MILLION research papers on high intestinal permeability aka “leaky gut”.

What is High Intestinal Permeability 

(we will call it “Leaky gut” from further below).

A leaky gut is increased permeability of the intestinal wall, through which bacteria and particles of digested food enter the bloodstream. This can cause inflammation and negative changes in the composition of intestinal bacteria, as well as lead to problems with the functioning of the gastrointestinal tract.

According to statistics, almost a quarter of the population of developed countries suffer from diseases of the gastrointestinal tract (gut issues), including irritable bowel syndrome (IBS), irritable bowel diseases including Crohn’s disease, and ulcerative colitis. The symptoms of these diseases are often similar:

  • Bloating, increased gas formation;
  • diarrhea, constipation;
  • Stomach ache;
  • Intolerance to certain nutrients and food sensitivities and allergies;
  • Fatigue, headache, brain fog.

These same symptoms are seen with increased intestinal permeability, but the medical community does not recognize leaky gut or small intestine as a separate disease. There are suggestions that increased intestinal permeability is one of the consequences of gastrointestinal diseases, but there is research focusing on high intestinal permeability as a precursor to chronic and autoimmune diseases.

Despite the lack of a clear understanding of how a leaky gut is associated with diseases in conventional medicine, the functional medicine approach uses the current scientific research. Unfortunately, it takes approximately 17 years to get the new research into the conventional clinical practice.  So, if you are experiencing increased gas production, abdominal pain, diarrhea, and other symptoms, you may decide to look for a functional medical practitioner instead of a conventional gastroenterologist.


Our guts are very vulnerable – many toxins may increase the risk of increased intestinal permeability.

What is Intestinal Permeability and when is it Increased?

The intestinal wall is not impermeable. If it were impermeable, water and nutrients would not be able to enter the bloodstream and then the organs. The intestinal lining also helps protect the body from endotoxins, bacteria, and viruses. 

Every time you eat, the level of permeability of the intestinal wall changes so that the body receives important nutrients.

Certain proteins are responsible for maintaining the integrity of the gut barrier. Thanks to them, as well as some other levels of protection, intestinal cells close the intercellular space and do not allow large molecules to pass through, and, subsequently, help the intestinal walls become more permeable when required.

Intestinal permeability is regulated at different levels. 

One of them is a physical layer of cells and mucous membranes that prevents the passage of large molecules. Another layer is not visible to the naked eye – it is controlled by the immune system. To respond to threats, the second layer uses inflammation as its’ main weapon. Gut bacteria are responsible for the immune response, which from childhood “train” the immune system to recognize potential danger.

How Gut Bacteria Protect the Body

Since food and drinks are not sterile, foreign microorganisms enter the body with them. When the immune system recognizes them, it turns on the immune response.

It is because of the reaction of the immune system that increased permeability is accompanied by latent inflammation, which lasts about four hours after eating. This means that after each breakfast, lunch, snack or dinner, the body goes through some stress. Inflammation increases with the intake of large amounts of fatty foods, sugar, and alcohol.

This is how a healthy intestinal wall works. But sometimes the proteins responsible for permeability do not manage this task efficiently. The work of proteins is influenced by genes and nutrition, stress, alcohol, certain drugs, and dysbiosis – an imbalance in the gut bacteria and yeast. Age may also play a role in disrupting the integrity of the gut.

What are the Risks Associated with Increased Intestinal Permeability?

As I mentioned earlier, every meal is potentially accompanied by a little hidden inflammation. This affects many bodily processes, including insulin levels, liver function, and intestinal permeability. Frequently eating large amounts of food stimulates the immune system that responds with inflammation to deal with the constant threat.

A growing body of research suggests that increased intestinal permeability is a precursor to some diseases.

Along with dysbiosis and translocation of microbes when they are out of place, this condition is associated with the risk of developing several chronic and autoimmune diseases:

Chronic diseasesAutoimmune diseases
Alzheimer’s diseaseirritable bowel syndromeNon-alcoholic liver diseaseIrritable Bowel Disease (Crohn’s and Ulcerative Colitis)Type 1 diabetes mellitus (childhood diabetes)Systemic lupus erythematosusmultiple sclerosisCeliac disease

An autoimmune disease is a condition in which the immune system mistakenly attacks healthy cells. The exact reasons for the development of this type of disease are unknown: scientists suggest that genetic factors, some drugs, and microorganisms can influence this.

How Meals and Timing Affect the Digestive System

The digestive system is a complex mechanism influenced by genetics, nutrition, and lifestyle. Often, in terms of the impact of nutrition on the body, only the type of food is considered, but when, how, and how much you eat also plays an important role.

Meal Timing

Research shows that 10% of genes exhibit circadian fluctuations. This means that the activity of their expression depends on the time of day. Human digestion works like a clock, which includes preparing the body for food intake, digestion, and then repair of the intestinal mucosa and cells.

People who work nights and often change time zones are more at risk of obesity and type 2 diabetes. This may be due to sleep disturbances and eating at night.

Perhaps you yourself have noticed that large and hearty dinners at night can cause discomfort. The most common of these is a feeling of heaviness, heartburn, pain, and nausea.

The Amount of Food

Overeating is the other extreme, which disrupts digestion. It is often associated with eating disorders and being overweight, which increases the risk of various diseases, such as colon cancer.

Studies show that calorie restriction can regulate intestinal permeability, and thereby reduce inflammation associated with excess fat tissue.

Duration of Meals

The process of digestion of food begins in the oral cavity with special enzymes that are contained in saliva. Chewing helps protect the esophagus from being damaged by food particles that are too large.

If you eat too quickly, there is a high risk that more air will enter the gastrointestinal tract, which can lead to gas, bloating, and abdominal pain. Slow chewing of food not only facilitates the work of the digestive system but also increases the intake of useful elements from food and avoids overeating.

The optimal number of times for chewing one piece of food varies from 5-15 times for soft foods, such as mashed potatoes, and 30-40 for hard foods, such as meat.

Frequency of Meals

The body gets energy from the glucose that comes with food (mainly, from carbohydrates). If all the glucose is not used for energy by the body, it is deposited in the form of adipose (fat) tissue. To get into the tissues, it needs insulin, a hormone that helps regulate blood sugar levels.

Within a few hours without food, the body uses up all the sources of energy received from the last meal and begins to burn sugar reserves that are stored in fatty tissues. It can improve the body’s sensitivity to insulin and reduce the risk of type 2 diabetes.

On the one hand, fasting is good for gut bacteria. Studies show that the activity and abundance of Akkermansia muciniphila increases during the 16-hour fasting period, but decreases with the next meal. This type of bacteria stimulates the intestines to produce more mucus.

However, intermittent fasting is not for everyone: this approach has a number of limitations. Before you try this diet, you should consult with your doctor. Especially intermittent fasting is not recommended for people with diabetes, eating disorders, children under 18, and pregnant or breastfeeding women.

How does the microbiota affect the gut’s protective barrier?

The health of the intestinal wall, its protective functions, including permeability, depends on the state of the microbiota.

Healthy gut bacteria produce short-chain fatty acids, including butyric acid. This is the main source of energy for colonocytes – intestinal cells that line its walls, being responsible for their integrity and the production of a protective mucous layer.

What is Butyric Acid and Why is it Needed

The mucosal layer is rich in nutrients and acts as a protective barrier that only allows certain intestinal contents to pass beyond this barrier.

With a decrease in the amount of the mucous layer, the risk of increasing the permeability of the wall increases.

The state of the protective barrier depends on the composition of the gut microbiota. For example, Bifidobacterium and  Lactobacillus bacteria maintain intestinal acidity, provide protection against inflammation, and help boost immunity. The higher the proportion of beneficial bacteria in your gut, the better protected you are from unwanted conditions and diseases.

In 2018, the results of a mouse study were published in the Journal of Diabetes Research. The scientists found that with obesity-induced dysbiosis, the amount of Akkermansia was significantly reduced and this relationship directly affected the increase of the permeability of the intestinal walls.

The level of beneficial bacteria depends on the variety and amount of dietary fiber in the diet. Probiotics help increase the proportion of these bacteria – foods that contain beneficial bacteria Lactobacillus and  Bifidobacterium, such as yogurt, kefir, sauerkraut, kombucha.

How to Reduce Your Chance of Leaky Gut

The key to a healthy gut is what, how much, and when you eat. It is better to cook food at home: this way you can control the amount of salt, sugar and fat, monitor the diversity of the diet. The more different plant foods you eat, the more diverse the composition of the microbiota, and therefore the better the protection of the intestinal wall.

The more you eat at a time, the longer the intestinal walls remain permeable. Try not to eat at night and do not snack late at night: the body’s circadian clock adjusts the intestines to other processes.

Eat Healthy Foods – Mediterranean Diet

Sometimes avoiding overeating is not easy, especially during the holidays. Here are some tips to help you deal with the urge to overeat:

  • Don’t skip your main meals and plan your meals ahead of time.
  • Pay attention to portion sizes. A small plate helps you eat less.
  • Avoid snacks – chips, crackers. Due to the high content of salt and sugar when they are consumed, it is difficult to comply with the portion size.
  • Eat fresh fruits and vegetables. They contain a lot of fiber, which gives a feeling of satiety for a long time and reduces the need for a snack.
  • Do not be distracted by TV and phone when you eat. Concentrate on the food itself – this will allow you to understand in time when you are full.
  • Eat slowly and place your fork on your plate as you chew each bite.

Exercise: not only will you improve your cardiovascular health, but you will also increase the diversity of gut bacteria that strengthens your gut walls.

This does not constitute medical advice, always seek the direct advice of your Doctor or Medical Provider for your specific health care or needs.

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