The Gut Microbiome - what is it, why it matters and how to help it thrive when you are struggling with IBS
World Microbiome Day, which is observed annually on 27th June, is an opportunity for us to learn more about the gut microbiome and the microbial world that lives within and all around us and why it is so valuable to humans as well as the planet.
To celebrate World Microbiome Day in this blog post I discuss what the gut microbiome is, why it’s so valuable and how to help your gut microbes thrive even when you’re struggling with IBS.
The Gut Microbiome - what is it?
The microbiome is the genetic material contained within the diverse range of microbes (bacteria, fungi, protozoa and viruses) that live on or inside the human body. The number of genes in all the microbes of one person’s microbiome is 200 times greater than the number of genes in the human genome!
The gut microbiome refers to all of the microbes and their genetic material found in the gut and is as unique to each individual as the human fingerprint.
We are first exposed to microbes when passing through the birth canal but this begins to diversify as we grow and develop. There is some evidence to suggest we are exposed to microbes in the womb but more research is needed. There are trillions of bacteria and other microbes and it can weigh anything up to 1-2kg, that’s roughly the same as the human brain! Many factors can influence this delicate ecosystem including normal delivery or Caesarean section, diet, stress, the environment and drugs, and in particular antibiotics.
The Gut Microbiome - why it matters
Gut bacteria play many integral roles in the body including helping to digest food, manufacturing B vitamins and vitamin K, and producing the neurotransmitters serotonin, dopamine and GABA (gamma amino butyric acid) which are central to mood regulation. They also produce short-chain fatty acids (SCFAs) which serve as fuel for the colonocytes (colon cells) and help dampen inflammation in the body.
The gut wall is another line of defence in the body helping to regulate the immune system.
Gut health is essential to overall health and so optimising it is extremely important. Hippocrates, the father of modern medicine suggested over 2,000 years ago that “all disease begins in the gut”.
Research into the gut microbiome is ongoing but imbalances in it have been linked to weight gain, IBS and inflammatory bowel disease (IBD), diabetes, autoimmune and mental health conditions.
The Gut Microbiome - how to help it thrive
A diet high in processed foods, sugar, caffeine and alcohol and stress can lead to disturbances in the gut microbiome. However, there are many ways to support gut health through the diet and lifestyle by eating the right foods and reducing stress.
So what foods help to feed the gut microbiome?
1. Fibre-rich foods
Dietary fibre is the part of plant-based foods like fruit, vegetables and wholegrains that mostly passes through the digestive tract without breaking down or being digested. There are two types; soluble and insoluble and both are needed in the diet and have their own individual benefits.
–soluble (oats, barley, beans, peas, lentils, potatoes, apples, pears, citrus fruit). It forms a gel that soothes and regulates the digestive tract and aids regular bowel movements.
–insoluble (wholegrains, wheat bran, lentils, nuts and seeds, fruits and vegetables with the skin on). It bulks up the stool allowing the elimination of waste.
Both help the colonocytes to replenish and repair.
2. Fermented or Probiotic Foods
Fermentation is the process whereby sugars in a food are broken down by bacteria and yeast resulting in the production of beneficial bacteria or probiotics.
Examples of fermented foods and drinks are sauerkraut, kimchi, sourdough bread, kefir, live yoghurt and kombucha. These probiotic foods and drinks are thought to help boost the diversity of beneficial bacteria in the gut although as of yet there is no strong evidence to back this up.
3. Prebiotic foods
Prebiotics serves as ‘food’ for the probiotic or beneficial bacteria helping them to grow and survive. Examples are onions, leeks, garlic, asparagus, chicory root, dandelion greens, Jerusalem artichoke, bananas, oats, wheat bran and other fibre-rich foods.
One thing to remember is that water helps support healthy digestion and elimination and is especially important when eating sources of insoluble fibre.
Now that you know what the microbiome is and how to look after it and help it thrive, what additions could you make to your diet? Are there any other changes you could make?
