We all know that eating healthy diet for our overall health but research over the last 10 years has shown a solid link between eating healthily diet and our immune system via our gut microflora (the micro-organisms in our gut). Our gut bacteria train our immune systems to behave appropriately to the environment. We are normally exposed to these bacteria initially via our mother giving birth to us, and this process colonises our gut and helps to mature the immune system and develop a larger diversity of immune cells.
Our relationship with our gut bacteria is symbiotic – this means that our body houses the bacteria and provides food whilst the bacteria participate in and support our health. There are several ways in which our diet affects the types of bacteria we nurture within our gut and how they affect our immune system:
- Produces short-chain fatty acids– our gut bacteria ferment dietary fibre from vegetables, fruits and wholegrains to produce short chain fatty acids (SCFA). SCFA are an important energy source for the cells of our colon along with regulating the immune process, healing, reducing inflammation and protection from cancer and other diseases.
- Protect against pathogens– as the first line of defence, gut bacteria work by stimulating the immune response to protect against pathogenic bacteria. In addition, Lactobacilli and Bifdiobacteria can transform substances rich in fibre into lactic acid when there is no oxygen. Lactic acid acidifies our intestine and slows down proliferation of pathogenic bacteria.
- Train our immune system– gut bacteria can selectively suppress the immune response so that we can tolerate some substances in our environment, which is important for preventing autoimmune disease and allergies. The bacterial genes can also regulate local and systemic inflammation.
Eating a diverse diet, particularly earlier in our lives, with a wide range of fruits, vegetables, wholegrains, nuts, herbs, spices and seeds will help grow and create a balanced gut microflora which influences the balance of our immune system. A more diverse gut microflora is more resilient against attack from pathogens and environmental stress, as the immune system response is mediated appropriately, and supports optimal immune health.