The idea of a leaky gut has always struck me as rather amusing, it’s such a funny name, but if you are a sufferer you won’t be laughing. Most of us go through periods of poor digestive function, often linked to stress and illness, but prolonged poor digestion will put you at risk of leaky gut, and that can have profound effects on your long term health.
It’s not easy to tell if you’ve got a leaky gut but if you have suffered from periods of acid indigestion, bloating, constipation and flatulence, and if you have an increasing number of inflammatory symptoms: rashes, joint pain, headaches, arthritis, hay fever, eczema, then it’s worth investigating.
Before we delve into why your intestine might be leaking let’s talk about how it’s supposed to work.
Your digestive tract is a long and winding tube between your mouth and Uranus. (You know what I mean.) Technically, the food in your gut is ‘outside’ your body: in its partially digested, unabsorbed state it sits in your digestive tract, completely insulated from your cells. In this magical and transformative place ‘food’ is broken down into ‘nutrients’ so that you can absorb them.
The lining of the tube is one of the most brilliantly engineered wonders of the known universe; a tightly regulated barrier that plays an important role in your immune system. Think of it as customs and immigration: nothing alien is allowed through.
If it breaks down, you’re in trouble.
Friend or foe?
To maintain its integrity, your gut cells need the help of mucus, digestive enzymes and gut flora (friendly bacteria). The cells that make up the gut wall are nourished by the gut flora, and the joins between cells are called tight junctions – for a good reason.
In order to enter your body nutrients have to make their way through one of these cells. First they have to cross the membrane facing the gut, then they travel through the cellular cytoplasm, then they cross the cell membrane on the other side until, finally, they are ‘inside’ your body. Two border controls, and a complex array of receptors and transporters, to make sure the molecules get from A to B in an orderly manner.
There’s a good reason for this. The body is very particular about what molecules are allowed in. For example, although you may eat chicken for lunch, you don’t absorb chicken into your body. The chicken protein is broken down to amino acids, little protein building blocks, and these are absorbed piece by piece. When they get to the other side they are linked together again, but in a different formation; they are rebuilt as human proteins, or ‘self’. The only proteins the body allows to circulate untouched inside the body must be labelled ‘self’. Any other proteins would be classified as invaders and the immune system would be mobilised to destroy them using the process of inflammation.
To get to the final stage of being accepted into your cells and used in your body food molecules will have been carefully processed all the way down your digestive tract. In the case of proteins, digestion starts in the stomach where the huge and complex molecules are unravelled and chopped into smaller fragments, and they keep on getting broken down all the way through the gut. It’s vitally important that each step of the way happens as it’s supposed to, otherwise you start to get the wrong food in the wrong place at the wrong time, and that is a problem for your immune system.
It takes guts
Your stomach is the most important stage of digestion for all sorts of reasons. It secretes an extremely strong acid to begin the process of protein digestion and this, conveniently, also has the effect of killing any stray microbes – bacteria, yeasts etc – that have hitched a ride on your food. This acidity also triggers the next phase of digestion.
During periods of illness, infection and prolonged stress, it’s common to find that stomach function decreases, acid secretion is reduced with the result that food isn’t broken down properly and the bugs aren’t killed. The ‘chyme’ (the name for the liquid that leaves your stomach after this stage of the digestive process) doesn’t trigger the next phase of digestion efficiently, and undigested proteins, bacteria and yeasts travel through to the small intestine.
The other thing that happens during stress is that the movement of the gut tends to slow down leaving food sitting in the digestive tract for longer periods, and creating the perfect environment for fermentation.
This is a significant change in the chemical environment in your gut, enough to trigger a shift in gut flora composition and a deterioration in the health of the gut wall. Now, the gut struggles to maintain its integrity, the cells are subject to inflammation and, frequently the tight junctions between cells start to open up.
When this happens, whole proteins are able to cross from ‘outside’ (the lumen of the gut) to ‘inside’ (your body cells) without border control. Instead of a manageable stream of amino acids, your body is faced with whole proteins: chicken, peanut, gluten, casein… and it launches an immune attack.
That is the start of a food sensitivity or allergy.
The sort of immune response associated with foreign proteins is called ‘inflammation’ which happens when the body mobilises the complement system. The longer this goes on, the more inflammatory symptoms you’re likely to observe.
(By the way, babies are born with ‘leaky gut’ so that they can absorb milk proteins more easily; the tight junctions don’t close properly until at least 6 months old and sometimes later. So if you are gleefully feeding your hungry 4-month old baby porridge and rice and yoghurt and bread, don’t be surprised if you start to observe allergic and inflammatory symptoms.)
Finding food sensitivities
As you can see, by the time you develop food sensitivity symptoms you are trailing a history of digestive problems in your wake. I frequently get calls from prospective clients asking if I ‘do’ allergy testing.
That’s because the way to protect you from food sensitivities isn’t to get you to stop eating that food, it’s to heal the tight junctions in your gut. If we test for allergies and the test confirms you’re sensitive to gluten and dairy and eggs and nuts and lentils (the common ones) all we’ve really discovered is that these foods have managed to enter your blood stream undigested. If you stop eating those foods, but you do nothing to repair your digestive function, then you will go on to develop further food sensitivities, and before long you will believe there’s nothing you can eat. I’ve had clients like this, whose diets before they come to see me have been getting worse and worse, and who are getting sicker and sicker, because they are suffering from malnutrition.
With food allergies, you need to heal the gut at the same time as looking at the diet. Digestive function needs to be brought back to normal. It’s a good idea to stop eating the foods you suspect are irritating you while you do that work but in the long run, most people should be able to go back to a full, healthy diet with no problem.
Of all the foods that lead to leaky gut, we’re starting to understand that wheat is the biggest culprit. gliadin, one of the proteins found in wheat, but also in barley and rye, raises zonulin levels in the gut, which opens the tight junctions. When combined with a sub-optimal gut flora this is the cause of chronic inflammation linked to all sorts of diseases.
Looking after your digestion is a critical success factor for good health and longevity. If you suspect yours is not working as well as it could do, let’s have a chat.