Leaky Gut 101: The Science Behind Leaky Gut

For a long time, the existence of Leaky Gut was almost like a conspiracy among mainstream physicians, adopted primarily by professionals in the natural and alternative medicine space. However, it has slowly been gaining traction over the years and researchers are starting to investigate its role in gut health. Since Leaky Gut is not well understood, it is not an official medical diagnosis. In this article, we will briefly dissect the science behind Leaky Gut.

A Healthy Gut

The gastrointestinal tract is made up of cells which are tightly held together by tight junctions which work together to maintain the structural integrity of the cells. On top of these cells is a layer of mucus which protects the intestinal wall from digestive enzymes, food residue and bacteria in the gut. Gut bacteria is located above the mucus layer in the gut, this is known as the gut microbiota. The role of the gut microbiota is to assist in nutrient metabolism, protecting against pathogens and support the structural integrity of the mucosal barrier in the gut.

Together they maintain the structural integrity of the gastrointestinal tract to ensure no bacteria, toxins and undigested food particles “leak” out of the gut and into the blood stream. If something goes wrong, then there is a risk of developing increased intestinal permeability or “Leaky Gut”.

What Might Cause Leaky Gut?

  1. A protein called zonulin has been found to weaken tight junctions when overstimulated, making the gut more prone to leakage. Zonulin is believed to be stimulated by gluten and certain types of bacteria.
  2. High levels of inflammatory markers may also contribute to Leaky Gut or make it worse. Wide spread inflammation might take place after some gut contents leak out and the body responds by releasing chemicals as a defence mechanism. Inflammation may also be stimulated by a change in the gut microbiota and deficiencies in some nutrients such as vitamin D, vitamin A and zinc.
  3. An imbalance of microorganisms in the gut may increase the number of bad bacteria which can signal the release of inflammatory markers which may cause increased permeability. The gut microbiota can be altered by various factors such as excessive antibiotic use, chronic stress, infections, caesarean delivery and a poor diet.
  4. Excessive alcohol intake has been linked to the disruption of tight junctions and changes to the diversity of gut bacteria.
  5. It is believed that excessive use of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) such as ibuprofen or aspirin can damage the surface of the intestinal wall. NSAIDs promote the generation of reactive oxygen species and inhibit the production of a molecule which regulates intestinal blood flow, mucus secretion and protects the intestinal wall.

Consequences of Leaky Gut

Currently, it is not clear if Leaky Gut is a symptom or the cause of disease. It has been associated with a few conditions such as Coeliac disease, Type 1 Diabetes, Crohn’s disease, Irritable Bowel Syndrome (IBS) and food allergies.

Tips to Minimise the Potential Onset of Leaky Gut

  • Choose foods rich in fibre which support the growth of good bacteria such as wholegrain breads and cereals, fruits and vegetables, nuts.
  • Add probiotics rich foods to your diet which can improve gut health such as sourdough bread, yoghurt, tempeh, sauerkraut and kefir.
  • Limit intake of refined carbohydrates, saturated fats, processed foods which negatively influence diversity of the gut microbiota and increase inflammation.
  • Avoid excessive consumption of alcohol.
  • Limit used of NSAID medications and speak to your Doctor if you would like to discuss an alternative medication.

This article was written by Accredited Practising Dietitian, Fatima Hallal. Fatima completed her Master of Nutrition and Dietetics at the University of Canberra in 2018. Fatima is a regular contributor to The Gut Health Dietitian site.