The lining of the gastrointestinal tract is made up of several thousands of square feet of intestinal epithelial cells (IEC) that act as a barrier against bacteria, toxins, undigested food, and the bloodstream. This lining also acts as a gate system to absorb nutrients from food and release it into the bloodstream where they will be used throughout the body.

Under normal conditions, there are minimal imperfections in this barrier system. However, in Leaky Gut Syndrome, the tight junctions in between each of the epithelial cells become defective and allow for widespread direct communication between the intestinal contents, bacteria, and the bloodstream. This ongoing and long-term injury to the gastrointestinal tract can lead to inflammation manifesting as chronic conditions such as Irritable Bowel Syndrome or Functional Dyspepsia, and, in genetically predisposed people, Inflammatory Bowel Disease (Ulcerative Colitis or Chron’s Disease), and autoimmune diseases such as rheumatoid arthritis and type 1 diabetes.

Much research has recently emerged in regard to the gut microbiota and its role in immune regulation as well as how the IEC acts as a protective barrier against harmful substances entering the bloodstream. Goblet and Paneth cells, both of which are embedded within the IEC, secrete substances that contribute towards protection of that barrier. The IEC and immune cells that produce IgA (antibodies that work against invaders), work together to protect against invasion. The immune system that we are born with is regulatory of the tight junctions of the IEC. In addition, several receptors on the mucosal side of the IEC communicate with the microbiota and in the setting of tissue damage, leading to an immune response by the body for protection. Disruption of this system can occur due to antibiotic usage, or a diet high in processed foods, for example. This disruption then leads to inflammation. Moreover, the gut has a major influence on the blood-brain barrier of the brain (which has the same type junctions as the barrier in the IEC) due to its hormonal secretion. Disruption in its permeability may lead to degeneration in the neurological system, seen in cases of patients who have been found to have Celiac Disease, which also have some features of Schizophrenia, Autism Spectrum Disorder, dementia, Alzheimer’s Disease, and depression. Therefore, the microbiota of the gut needs to be properly balanced in order for the brain/gut axis to work effectively. Even in people who have Celiac Disease without experiencing symptoms, there are changes in neurotransmission within the central nervous system when the microbiota is out of balance. Dysregulation of the immune system has been found in patients with Autism Spectrum Disorder and post-mortem evidence in a small study showed that 75% of the individuals had dysfunctional barrier permeability and dysfunctional inflammatory signaling molecules.

While Leaky Gut is still not a fully accepted condition by the medical community due to the lack of strong clinical research in this area, many practitioners have begun looking at the data emerging from the basic sciences and have acknowledged its importance in the homeostasis of the gut and to the overall health of patients. With lifestyle adjustments, many of these patients who have functional gastrointestinal diseases, including those regulated by the immune system, are able to be less symptomatic and feel better, despite non-modifiable factors (such as ethnicity, genetics, environment, etc.).

Symptoms of a leaky gut are non-specific and variable in its presentation, some of which may include:

• Chronic bloating, diarrhea, constipation
• Eczema, psoriasis, acne
• Autoimmune diseases (i.e. Rheumatoid Arthritis, Psoriatic Arthritis)
• Food intolerances/allergies (i.e. gluten sensitivity)
• Chronic fatigue
• Memory loss, brain fog
• Headaches
• Nutritional deficiencies
• Diagnosis of Ulcerative Colitis or Chron’s Disease

 

Like a loaded gun, one has to pull the trigger for the gun to shoot a bullet. Even if someone is genetically predisposed to having autoimmune diseases or IBD (the “loaded gun”), it does not mean that they have no control over the disease process; daily habits make a difference in whether these conditions become symptomatic (“pulling the trigger”). Therefore, here are several ways to optimize the health of the gastrointestinal tract:

1. Decrease consumption of processed food: the Standard American Diet (SAD) lacks in fiber and essential nutrients and is loaded with sugar and unhealthy fats. These substances, when in abundance, have been known to cause dysregulation in the mucosa of the gastrointestinal tract and consequently produce an inflammatory response, contributing to metabolic disturbances throughout the body, as well as obesity. Processed foods include foods found at fast food restaurants, sugar-sweetened beverages (even those that are labeled “diet”), boxed foods, etc. Shopping the perimeter of the grocery store is the best way to avoid processed foods.
2. Decrease alcohol consumption: it has been found that certain bacteria in the gut, when in the presence of alcohol, increase in numbers and accumulation of endotoxins which lead to increased permeability of the IEC by affecting the tight junctions between cells. Not only is moderation in alcohol consumption crucial to the gut, it is also important for overall health. Current guidelines recommend no more than 2 servings of alcohol for men daily and no more than 1 serving daily for women. Best yet, avoid alcohol!
3. Increase consumptions of fruits, vegetables, and plant-based fats: Phytochemicals, which are compounds found in fruits and vegetables, in addition to vitamins and minerals, contribute to a regulated and optimized barrier system in the gut due to its numerous interactions with receptors on the surface of the IEC in which they play a major role. In addition, fruits and vegetables act as prebiotics, which feed the good bacteria in our gastrointestinal tract to keep it healthy. A diet that emphasizes omega-3 fats (i.e. raw walnuts, flax seeds, chia seeds, etc.) is anti-inflammatory in nature, whereas a diet that emphasizes omega-6 fats (as found with the SAD) contributes to an inflammatory environment. While there is a lack in strong clinical research in this area, it is widely known in the medical community that those who eat a diet high in fruits and vegetables have lower risk of developing gastrointestinal disease by not only lowering risk of inflammation but also lowering the colonies of disease-causing bacteria, and many practitioners see major improvements in symptoms in those suffering from such conditions. Current guidelines recommend a minimum of 5 servings of vegetables and fruits daily.
4. Decrease animal protein intake: there is abundant research in the role of diet in the integrity of the bacterial environment in the gut, also known as the microbiome. Changes in diet can cause drastic microbiome changes in as little as 24 hours. Recent data have shown that diets heavy in animal protein lead to proliferation of disease-causing bacteria in the gut, whereas those who consume plant-based protein (such as pea protein) have an increased number of gut-healthy bacteria and lower risk of developing inflammatory bowel disease. Of note, red and processed meat consumption have been linked to the development of colon cancer (due to its inflammatory effects), and its intake can increase levels of trimethylamine-N-oxide (TMAO) which is a compound that has been implicated in atherosclerosis, ultimately leading to cardiovascular disease. Therefore, consume animal protein sparingly.
5. Probiotics and other over-the-counter supplements: as mentioned earlier, the homeostasis in the microbiome plays a vital part in gut health. There is a delicate balance between healthy bacteria species such as Bifidobacteria and Lactobacilli, and unhealthy ones such as Bacteroides and Alistipes. To illustrate this important point, Bifidobacteria and Lactobicilli both produce short-chain fatty acids (SCFA), which have been shown to be anti-inflammatory and maintain a healthy mucosal barrier in the gut. When there is a lack of balance in the “good” vs “bad” bacterial colonies, such as from poor dietary choices or taking antibiotics, there is a shift in microbial activity in which the “bad” bacteria may take over. This is best seen in cases when patients acquire profuse diarrhea due to the over-colonization of Clostridium difficile when finishing a round of antibiotics. Probiotics have gained popularity over the last few years due to its enormous contribution in balancing the microbiome and ensuring the “good” bacteria is prevalent throughout the gastrointestinal tract. There are now hundreds of different types of probiotics, however, because they are not regulated by the Food and Drug Administration, their potency and shelf-life may not be reliable. For best results when using probiotics, take them on an empty stomach 30 minutes before a meal (when acid levels are lowest and least likely to kill the probiotics) and also look for the GMP (Good Manufacturing Practices) label on the bottle, as these companies abide by FDA-rules when manufacturing these products. In addition to probiotics, Dr. Singh in our office recommends Leaky Gut Revive which helps optimize the IEC and mucosal barrier. He has seen excellent results from this product with his own patients.
6. Manage stress: Stress affects all people. However, when stress levels increase to distressing levels, it can have psychological and physical detrimental effects. There is robust research emerging in regards to the brain-gut-axis, which shows gut health directly impacting brain health and vice-versa. Unmanaged psychological stress has been linked with decreased gastrointestinal motility, increased IEC permeability, negative shifts in the microbiota, to name a few. All these can lead to inflammatory bowel disease, irritable bowel syndrome, GERD, etc. A classic example of how stress affects the gut is seen in children suffering from anxiety, manifesting itself as a daily “tummy ache” in the mornings before going to school, which leads to multiple school absences and poor school performance. Managing stress and anxiety are best done by meditation, journaling, Yoga, talk therapy, and psychotherapy.

 

While the recommendations above can lead to improvement in the health of the gut, some people do not experience full relief of their symptoms. In those cases, an Elimination Diet is recommended in order to pinpoint the food sources that contribute to the inflammatory response in the gut, in addition to balancing out the microbiome and providing relief of systemic symptoms. The Elimination diet is a short-term diet in which patients eliminate foods that are well-known for causing gastrointestinal inflammation, such as gluten-containing grains, alcohol, dairy, some meats, etc. This diet is followed for a few weeks and then slowly, each food is re-introduced one at a time to find any returning symptoms. A complete guide and further reading can be found here.

In conclusion, Leaky Gut Syndrome is now being more understood as a condition that affects the gut leading to several chronic conditions. One may be predisposed to developing such conditions, but it is possible to optimize the environment and microbiome of the gastrointestinal tract. Each individual has different needs, therefore talk to your doctor today to find out how you can best improve your gut health.

 

REFERENCES

 

Keita, Åsa V., and Johan D. Söderholm. “Mucosal permeability and mast cells as targets for functional gastrointestinal disorders.” Current opinion in pharmacology 43 (2018): 66-71.

 

Konturek, Peter C., T. Brzozowski, and S. J. Konturek. “Stress and the gut: pathophysiology, clinical consequences, diagnostic approach and treatment options.” J Physiol Pharmacol 62.6 (2011): 591-599.

 

Metidji, Amina, et al. “The environmental sensor AHR protects from inflammatory damage by maintaining intestinal stem cell homeostasis and barrier integrity.” Immunity 49.2 (2018): 353-362.

 

Obrenovich, Mark EM. “Leaky gut, leaky brain?.” Microorganisms 6.4 (2018): 107.

 

Peterson, Lance W., and David Artis. “Intestinal epithelial cells: regulators of barrier function and immune homeostasis.” Nature Reviews Immunology 14.3 (2014): 141.

 

Purohit, Vishnudutt, et al. “Alcohol, intestinal bacterial growth, intestinal permeability to endotoxin, and medical consequences: summary of a symposium.” Alcohol 42.5 (2008): 349-361.

 

Singh, Rasnik K., et al. “Influence of diet on the gut microbiome and implications for human health.” Journal of translational medicine 15.1 (2017): 73.