Welcome to part two of my three-part leaky gut blog series! In the series, we’ll be exploring everything you need to know about leaky gut syndrome. Last week, we looked at the causes and signs of a leaky gut (if you missed it, you can link back to it here
In this week’s article, we will be taking a closer look at the impact a leaky gut can have on your physical and mental health and wellbeing.
As we discussed in the last article, a leaky gut occurs when a protein called zonulin is produced in excess, which causes the tight junctions between the cells of the gut to become compromised, forming ‘gaps’ between the cells. This allows pathogens and other substances to pass directly through to the bloodstream without first being filtered by the immune cells of the gut, resulting in a systemic inflammatory response. Leaky gut has been linked to a host of conditions including rheumatoid arthritis, type 1 diabetes, psoriasis and obesity, and even mental health conditions including depression and schizophrenia (1). I see this in my clinic on a regular basis, and many of my clients see major improvements in their health conditions once they focus on improving the health of their gut.
So, let’s take a look at some of these conditions in more detail...
Leaky gut and chronic inflammatory disease
In recent years, rates of chronic inflammatory diseases such as obesity, insulin resistance and metabolic syndrome have been rising. In fact, it is estimated that around one in four adults and one in five children in the UK are now obese (2) - and leaky gut syndrome may have a part to play. When pathogens do not get filtered through the body’s gut immune cells, the body activates an inflammatory response, causing the production of pro-inflammatory cytokines (chemicals) such as interferon gamma (IFN-γ) and tumor necrosis factor alpha (TNF-α), which not only cause inflammation, but further loosen the tight junctions in the gut – a vicious cycle! High levels of these cytokines have been seen in chronic inflammatory diseases such as those mentioned above (3), suggesting that a leaky gut has a role in the development of these conditions.
Leaky gut and autoimmune disease
Autoimmune disease occurs when there is dysregulation in the immune system and it mistakenly attacks the body’s tissues, instead of protecting against harmful pathogens. While there are over 80 autoimmune conditions that can be present in practically all areas of the body, there is one symptom that is typical of all autoimmune diseases – inflammation. As most of our immune system is located in our gut (as much as 70-80%!), it may come as little surprise that a leaky gut has been linked to a number of autoimmune conditions, including Celiac disease, type 1 diabetes, multiple sclerosis, Ankylosing Spondylitis and psoriasis – many of which have been implicated by raised levels of zonulin. Interestingly, studies on celiac disease (an autoimmune condition occurring in response to eating gluten) have shown that when gluten is removed from the diet, zonulin levels decrease, inflammation decreases and the gut heals (4).
Leaky gut and mental health
You may have heard the gut being referred to as the ‘second brain’, which is because our brain and gut are closely connected and communicate all the time. Messages are sent from the brain to the gut, and vice versa, through a system called the gut-brain axis. As such, it is easy to understand why a leaky gut has been linked to mental health conditions including major depressive disorder, autism and schizophrenia. Research has shown these conditions are implicated by neuroinflammation (or inflammation of the brain and spinal cord) which has been associated with leaky gut syndrome. In several studies, raised levels of zonulin and inflammatory cytokines are seen in those with mental health conditions compared to healthy subjects (5), demonstrating the important role of the gut in these diseases.
One of the major ongoing questions among scientists in this area of research is whether leaky gut causes these conditions, or whether the conditions cause a leaky gut – a classic case of chicken and egg. At the moment, while evidence is emerging that leaky gut is the cause, the jury is still out. Either way, it’s clear that a leaky gut is implicated in these conditions; we also know that a healthy gut is essential for a healthy body and mind and as such, it is incredibly important to look after the health of your gut.
Stay tuned for part three of the leaky gut series! In the final article of this series, I’ll be discussing everything you need to know about healing a leaky gut, using the 5-R protocol – a tried and tested method for treating digestive conditions.
I’d love to know your thoughts. If you have any comments or questions, please let me know below.