Take care of your gut health to take care of your immune health.
Almost every type of disease has a gut connection somewhere.
Our initial interface with the outside world is via our gastrointestinal (GI) tract. It serves two main functions: absorbing useful substances into the body (taking in the good stuff) and restricting the entry of harmful substances (keeping out the bad stuff). The intestinal epithelium is the single layer of cells that line the GI tract and are on the frontline. As part of its protective role, the epithelium forms an important component of the intestinal mucosal barrier.
The cells found in those mucosal surfaces on a daily basis meet local challenges from foods, microbes and environmental pollutants. The result is a series of immunological decisions that on a single day exceed those made by the entire systemic immune system in a lifetime. Bacterial interaction with the mucosal immune system allows a complex transfer of information and there are many potential targets for intervention. Healthy microbiome equals healthy gut and healthy body.
The major modulating factor on the composition of our microbiome is the food we eat. In short, our gut microbiome is shaped by what we eat, so eat to feed your beneficial bugs! A diverse microbiome is a healthy microbiome with many different species playing different roles in your overall health. Diversity in the gut is achieved by diversity in the diet, especially plant-foods which are high in fibre. Different types of diet influence different species of bacteria.
Research has shown that a Mediterranean diet can improve microbiome diversity and reduce inflammation. This focuses on eating plenty of fibre from fruit, vegetables, nuts, seeds and whole grains; healthy fats like high-quality extra virgin olive oil; and good quality protein from meat or fish. Just an additional note that it is diet qualityy rather than the quantity per se, that matters when considering the benefits of adopting a Mediterranean diet. Avoid alcohol, salt, sweets and sugary drinks, and artificial sweeteners or other additives.
Research shows that a diet consisting of a variety of unprocessed foods of plant and animal origin might be associated with a gut microbiota that is beneficial for health. Conversely, a diet rich in ultra-processed foods, added sugars and salt, was linked to microorganisms associated with obesity, cardiovascular disease and type 2 diabetes.
Further support for your microbiome can come from prebiotic and probiotic foods. Prebiotics are the non-digestible component of food, which feed the "friendly" gut bacteria. Best prebiotic food sources include apples, asparagus, artichokes, bananas, broccoli, cauliflower, fennel, garlic, legumes, leeks, onions, pak choi, wheat and oats.
Probiotics are microorganisms and the 'friendly' gut bacteria and can be found in fermented foods such as sauerkraut, fermented tempeh (type of soya), miso, kefir and yogurt. Other antiviral, gut supporting foods include garlic, ginger, thyme and turmeric.
Unsurprisingly, eating a diet high in fiber, fruits and vegetables promotes a healthy gut and gut microbiota composition. Consuming a Western diet which is high in sugar, fat, salt and food additives can contribute to a decrease in beneficial bacteria which may increase intestinal permeability (also referred to as leaky gut) and inflammation.
Compared to some more restrictive and elimination diets, the Mediterranean diet appears to be a healthy option for supporting a diverse gut microbiome composition because it includes a balance between all food groups.