Hippocrates, who lived between 460BC and 370BC, stated that ‘all disease begins in the gut’. That was well over 2000 years ago, however, modern medicine is only just beginning to acknowledge the connection between what is going on in the digestive tract, and the many chronic health conditions people are experiencing today.
We know through modern scientific research that the intestinal epithelial (skin) cells are at the interface between the outside world and our internal immune system, and it is our immune system that keeps disease at bay. This helps us understand that when the gut is compromised, our immune system is impacted, which has flow on effects with our health!
Let me tell you a little more about the gut-immune interface. This interface consists of a very thin, one cell thick lining of the gastro-intestinal tract, known as the epithelium, along with two other important layers.
On the digestive tract side of the lining should be a thick mucosal layer. This layer is vitally important to protect the immune system from problematic bacteria that may be present in the digestive tract, and also to help with digestion and assimilation of important nutrients. On the inside of the epithelial layer are many immune system cells and chemical messengers in an area called the lamina propria.
Together these three layers constitute a healthy gut-immune interface. We need this to be strong and healthy to provide:
- a protective barrier
- easy passage of nutrients into the epithelial cells
- mechanisms to prevent intrusion of undesirable food molecules, environmental toxins and microbes from entering general circulation
- control via the tight junctions between epithelial cells.
Tight junctions are dynamic structures that are like gates that selectively allow for various food molecules, vitamins and minerals to pass through into the body’s internal circulation. We want these tight junctions to be strong, but they can quickly become weakened by inflammation.
What is interesting is that the most important ‘lever’ we have to modulate and improve the effectiveness of the gut-immune interface is with the foods we eat. The modern Western diet is typically high in sugar, saturated fat, emulsifiers and processed foods, which negatively impact the tight junctions, the microbial diversity in the gut, and the integrity of the mucous layer that protects the delicate one cell thick epithelial (skin) layer that lines our intestinal tract. When these defences are impaired, it leads to chronic inflammation throughout the body.
On the flip side, a diet that is high in plant based foods like fruits, vegetables, legumes and whole grains, along with healthy fats can improve the integrity of the tight junctions, improve the balance of microbes in the gut and strengthen the mucous layer to provide additional protection to the epithelial (skin) layer. Together these three factors improve immunity and decrease inflammation. This is where functional nutrition comes in.
In a functional nutrition approach to healthcare, we work through a number of steps to improve the health of the intestinal tract, and the microbes that live there. Firstly, we lower the intake of inflammatory foods for a time, increase the intake of gut friendly probiotic and prebiotic fibrous foods, and use various foods and supplements to support healing.
Step #1 - Removing Inflammatory Foods
For many it will be important to lower the inflammatory burden on the digestive tract by avoiding foods that are likely to cause inflammation or that you already know you may be intolerant to. This list may include gluten containing grains, dairy products, eggs, tree nuts, soy, corn and nightshade vegetables. Determining individual sensitives takes a little detective work, but it can be done. Ideally as the gut heals, many of these foods can be added back into the diet, but avoiding them initially takes the load off the immune system, allowing for faster healing.
Sugar is another food component to avoid as it fuels the growth of yeasts and pathogenic bacteria in the gut, which has been shown to impact the gut-immune interface. Processed foods, industrial oils and artificial additives are other potential culprits that can irritate the gut and lead to inflammation and disrupted gut microbes.
Step #2 - Adding Gut Friendly Foods
As well as removing inflammatory foods from your diet, it helps to focus on the foods that help your gut to heal. A plant based diet that is high in dietary fibre is incredibly beneficial for improving the diversity and balance of gut microbes. Some other food items that can help include:
- Bone broth, which can help to heal the cell walls of the intestines due to its high collagen content. Alternatively, collagen peptide powder can be purchased from health food stores, and can also be helpful in improving the integrity of the gut wall.
- Fermented vegetables such as kimchi and sauerkraut provide beneficial microbes and gut healing properties.
- Seeds such as chia, hemp and flax seeds also contain fibre to support healthy gut bacteria.
- Eating plenty of fruits and vegetables for their fibre, which acts as a pre-biotic to help improve microbial diversity.
- Healthy fats and omega 3 fatty acids, which encourage healing. Good sources of these include avocado, nuts and seeds, olive oil and fatty fish.
- Focusing on eating an anti-inflammatory Mediterranean type diet
Step #3 - Repairing the Gut with Supplements
You can sooth the inflammation and start to repair your gut with supplements that support healing. Probiotics are the obvious choice for this but you may also be advised to try other supplements such as aloe vera and slippery elm powder.
Digestive enzymes taken with meals can help to break down proteins, starches and sugars that could otherwise be undigested and pass through to the intestinal lining leading to an immune response, which increases the level of inflammation in the gut, and the body. Supporting the breakdown of foods into their smallest components can be very beneficial for supporting gut healing.
Step #4 - Reducing Stress and Fostering Positive Lifestyle Practices
In addition to the foods we eat, lifestyle practices can also impact the gut-immune interface. Any form of stress can impact the gut lining, which is why healing the gut must involve steps to address stress. Stress also contributes to inflammation due to the release of cortisol. When cortisol is continuously being released, it can be disruptive for your hormones, immunity, digestion and the balance of bacteria in the gut – all of which can make the symptoms of disease more severe.
A few of the things you can do to reduce the effects of stress include:
- Prioritizing self-care. It’s definitely not selfish to focus on self-care when you’re living with chronic health conditions, and making time for it can be a game changer for reducing the severity of symptoms.
- Becoming aware of how your body reacts when you’re under stress. This helps us respond to stress more quickly than you would otherwise.
- Engage in breathing practices that help us cope with stress, and signal to the body that it can relax. When we are stressed, we trigger the sympathetic (fight or flight) state of our nervous systems to kick in. Deep breathing is a quick and simple way to tell the body we don’t need to remain in the fight or flight state, and helps us return to the parasympathetic (rest and digest) state.
In addition to lowering stress levels, getting regular exercise, sufficient sleep and staying well hydrated are important lifestyle practices that improve our health and wellbeing.
In conclusion, it is important to consider the health of the gastrointestinal tract in the development and maintenance of chronic health conditions, including auto-immune conditions. Removing foods that are inflammatory and introducing more gut healing foods can improve the state of the digestive tract. Targeted supplements can speed up the healing process. Lifestyle practices such as managing and modulating stress will be a part of a long-term strategy to improve health and lower the risk of chronic health conditions.