This guestpost is by Dr Megan Rossi aka @TheGutHealthDoctor. You can read more about Megan at the bottom of the post.
“Leaky gut” is the latest pandemic said to be sweeping the globe, but is it worth all this anxiety-provoking hype? I decided it was high time I discovered for myself (and you guys!) by taking a closer look at the science.
First and foremost what is a leaky gut?
To understand what is meant by the term “leaky gut” let’s start with a quick revision of our digestive system. When we eat food it’s physically and chemically broken down (by firstly our teeth, then digestive enzymes, stomach muscles, acids etc.) as it travels from our mouth, down our esophagus, through our stomach and into our small intestine.
The small intestine is a truly fascinating part of our body, with a length of 7 metre and a surface area rivaling a tennis court, it’s the ultimate site for nutrient absorption.
In fact most of the nutrients from our food are absorbed in our small intestine, meaning nutrients move from our gut into our blood (and lymphatic) circulation – BUT in order for the nutrients to get into our circulation they need to cross the intestinal wall.
Our intestinal wall is made up of a barrier of cells (like bricks in a wall) that are effectively glued together by tight junctions (the cement). Our intestinal wall serves a dual purpose; like a bouncer at a club it allows the passage of the good guys (i.e. nutrients) and keeps out the bad guys (i.e. foreign matter).When these tight junctions become weak (or brittle), which scientist call ‘intestinal hyperpermeablity’ (aka leaky gut), some of the foreign matter is able to sneak across the intestinal wall and into our circulation (shown in the image below). This invasion can set off alarm signals throughout our body, which in turn activates our defense system triggering a cascade of negative side effects both within and outside our gut.
At this point some of you maybe freaking out thinking you’re body is being invaded because you’ve been “diagnosed” with a leaky gut.
But don’t panic, I am here to reassure you that having a leaky gut is not as black and white as you may have been lead to believe. In fact from time to time we all can have a slightly leaky gut without any major health consequences. What’s more, the stress induced by being “diagnosed” with a leaky gut may actually cause your gut to become more leaky! Yep that’s right being stressed can acutely increase the leakiness of your gut wall. This was shown in a really interesting clinical trial where they measured the gut leakiness in people before and after public speaking. What they found was that the people who were more nervous and stressed were the ones whose gut became leaky. Now there is some food for thought. De-stress = gut happiness!
Triggers of a leaky gut
So as I alluded to above, leaky gut is not a black and white “syndrome”. In fact when I described the tight junctions as cement that probably wasn’t fair, they’re more like doors that can open and close within seconds. In fact the tight junctions between our intestinal cells open and close all the time in response to a variety of things. This includes diet (e.g. high fat meal), exercise (e.g. long distance running), medications (such as some pain killers). These triggers tend to have only a short term effect on the tight junctions and therefore don’t seem to cause any major issues. That being said, in some diseases exposure to particular allergen e.g. gluten in people with coeliac disease, has a more sustained and severe effect on the tight junctions and therefore leakiness of the gut. However, if gluten is strictly avoided in people with coeliac disease then the tight junctions do their job appropriately and the leaky gut resolves. This brings forward the notion that leaky gut is an effect of an underlying disease rather than the cause of disease.
How do we diagnose it
There are actually several ways to measure how leaky your gut wall is. The gold standard method we use in research involves drinking different types of sugars and measuring the concentrations in your urine over several hours. BUT here is where I get quite passionate on the topic…before you go out and spend £££ on measuring your gut leakiness think to yourself, what is the purpose, what is the benefit? I personally believe that outside of research, for most people there’s not a lot to gain by measuring your gut leakiness. Why? Both human and mouse studies have shown that a leaky gut alone is insufficient to initiate disease, and therefore the current scientific consensus is that a leaky gut is indeed a symptom rather than a cause of disease. Moreover, despite research investigating both diet and novel drug therapies that target gut leakiness, to date none have been proven effective. So in short, yes you can measure it, but it’s not going to change nor inform how you manage your symptoms.
Where to from here?
As the science currently stands it is unlikely that a leaky gut is the root of your health problems, but instead a symptom of one. With this in mind it makes more sense to focus on the underlying cause of your gut symptoms rather than focusing on something like a leaky gut (which is somewhat arbitrary anyway).
So, how do you identify the underlying cause?
Your first port of call, particularly if you have ongoing gut symptoms such as tummy pain, altered bowel habits and bloating, should be to check in with your GP to rule out conditions such as coeliac disease and inflammatory bowel disease. Once these are cleared it’s worth discussing irritable bowel syndrome (IBS); a syndrome that affects 1 in 10 people.
If it turns out that IBS is the underlying condition, then I’ve got good news for you; there is strong evidence that dietary management (delivered by a registered dietitian) can effectively rid you of your gut symptoms. On that note, I think it’s also worth mentioning that several clinical trials have shown that a large proportion of people tend to mistake their IBS for wheat or gluten intolerances. This is why I always recommend people check in with a registered dietitian or registered nutrition instead of going at it alone- trust me guys, food and gut issues can be complicated stuff!
Want to know more about dietary management of IBS? Check out this article.