What is a leaky gut? It is a condition in which the gut (intestinal) lining becomes “leaky,” causing toxins and bugs to cross the protective lining and intrude into your system. This provokes inflammation and faulty gut bacteria. In fact, your immune system can also go haywire and start attacking your body’s own tissues as a result of leaky gut. 
A few decades back, Western medicine didn’t recognize “leaky gut” as a separate entity. However, the condition is now garnering attention in the scientific field with an alternative term called “increased intestinal permeability.”
In short, a leaky gut can give rise to a host of problems within the digestive tract and also beyond. A few chronic health problems linked to leaky gut include:
- Inflammatory bowel disease
- Celiac disease
- Irritable bowel syndrome
- Multiple sclerosis
- Rheumatoid arthritis
Thus, scientific experts are now studying the leaky gut (aka intestinal permeability) as a means of preventing or even treating such chronic diseases. 
What drives leaky gut?
Your gut lining is a complex multilayer system, made up of an outer “physical” barrier and an inner “functional” barrier. On the one hand, the physical barrier works to keep the invading bugs and toxins away. On the other hand, this barrier selectively filters to allow only essential nutrients and fluids into your system.
Tight junctions between the gut cells are the ones that make up the physical barrier. If the function of these tight junctions isn’t up to par, leaky gut syndrome ensues. 
The term ‘intestinal permeability’ stems from these opposing functions of the gut barrier, allowing a few molecules to pass through while barring the passage of others. Microscopically, the permeability is “normal” if there are no signs of intoxication or gut inflammation. 
The interplay of various factors can cause your gut to become abnormally leaky as listed below:
Imbalanced gut microbiome
The gut microbiome is an integral element and a central regulator of the gut barrier.  Its health should be balanced. If the microbiome health goes off the rails, so does the integrity of the gut lining. Too much of the bad bugs coupled with lower levels good bacteria can create holes in your gut lining, triggering a leaky gut.
Consuming the wrong diet
The current Western diet which is high in sugar and unhealthy fats and low in fiber can wreak havoc on the microbial harmony. The not so welcomed bugs can then breach the gut lining and finally enter your body.
Gluten is one of the key culprits behind leaky gut. This dietary protein can cause an excessive release of a protein called zonulin. Although this protein regulates the tight junctions, if over-released, zonulin can end up breaking these junctions.  This results in leaky gut. In fact, a surplus of zonulin also serves as one of the links between leaky gut and autoimmune disease.
For another subset of people, their genes are the one to be blamed for their leaky gut. These people are genetically more sensitive to any turbulence in their gut, causing the protective barrier to become hostile and leaky.
A good example of genetic predisposition is that you suffer from a mental health issue like depression because one of your siblings or parent has the same problem. It’s very likely that the same relative has a leaky gut that triggers emotional problems. And because you’re genetically related to this relative, your chances of acquiring both the gut and mental problems rise too.
Alcohol and stress
Drinking too much alcohol can perturb the gut microbiome balance, and even loosen the tight junctions, causing unnecessary leakage from your gut.
Chronic stress also makes the gut leaky, escalating the levels of toxins in your system. These toxins, in turn, lead to mental problems, in particular, depression.
Can Leaky gut be fixed?
So, you see how the gut barrier can go from being tight to leaky just because of a few lifestyle and environmental insults. The good news is that it’s never too late to fix the gut microbiome health and probably the leaky gut barrier. You may be able to achieve this goal by working a healthy diet (gluten-free if required), probiotics, and prebiotic supplements into your routine.
- Mu Q, Kirby J, Reilly CM, Luo XM. Leaky Gut As a Danger Signal for Autoimmune Diseases. Front Immunol. 2017;8:598. Published 2017 May 23. doi:10.3389/fimmu.2017.00598.
- Bischoff SC, Barbara G, Buurman W, et al. Intestinal permeability–a new target for disease prevention and therapy. BMC Gastroenterol. 2014;14:189. Published 2014 Nov 18. doi:10.1186/s12876-014-0189-7.
- Fasano A. Zonulin, regulation of tight junctions, and autoimmune diseases. Ann N Y Acad Sci. 2012;1258(1):25-33.