Micro-organisms are found all over the body, and in the gut there are up to 2kg of them, made up of more than 3 million genes. The gut microbiome is the total of all these genes.
While some gut microbes are common, the majority are unique to individuals, and there are many influences on our microbiota. They include diet from our earliest stage of life, our age, our genes, the delivery method used when we were born, where we live, stress, and taking antibiotics.
It's well known that gut flora play a beneficial role in our digestive health. These bacteria help us use undigested and unabsorbed carbohydrates, turning them into fatty acids to be used as energy sources and nutrients, and helping us absorb certain minerals. They also promote the growth of cells in the intestine while helping combat harmful species of microbe.
But the influence of our microbiota on aspects of health other than digestion is perhaps less known. An increasing body of research is focused on gut health and our immune system, along with allergies and other conditions. In New Zealand, Dr Elizabeth Forbes Blom at the Malaghan Institute is investigating the role of gut bacteria in the development of the immune system and whether prebiotics and probiotics can be beneficial.
“We think gut bacteria play a crucial role right from the very start of life; in developing a strong life-long immune system,” she says on the institute's website. “Generation A - The Allergy Generation - has been born. They are not mollycoddled or the product of over anxious parents. These kids are more likely to suffer from allergies, have more severe allergic reactions and they are less likely to grow out of them.”
Researchers are also looking into the relationship between gut microbes and weight. A Scientific American article tells us about how scientists are understanding that managing the gut bacteria ecosystem could help manage obesity.
“New evidence indicates that gut bacteria alter the way we store fat, how we balance levels of glucose in the blood, and how we respond to hormones that make us feel hungry or full. The wrong mix of microbes, it seems, can help set the stage for obesity and diabetes from the moment of birth,” the article says.
Initial research by the British Gut Project says a diversity of gut bacteria is key.
With increasing insight into the importance of the microbiome, it's important to know how we might improve our gut health. Although it's an emerging area of research, and our digestive tract houses a complex ecosystem, there are some areas we can consider if we're looking to improve our gut health.
1. Get your dose of fibre
A study published in the BMJ suggests fibre may help nourish the gut, while a University of Illinois study showed dietary fibre promotes a shift in the gut towards different types of beneficial bacteria. Among the foods that boost fibre intake are wholegrain breads, fruit, nuts and seeds, legumes, fruit and vegetable skins, wheat, oats and bran.
2. Consider prebiotics and probiotics
According to the European Food Information Council, probiotics and prebiotics may increase the numbers of beneficial bacteria in the gut. Probiotics are live microorganisms found in a variety of foods and dietary supplements. Prebiotics are non-digestible carbohydrates which can promote the growth and activity of beneficial gut bacteria, it says.
3. Manage stress
Studies suggest there is a relationship between stress and gastrointestinal disorders, with symptoms worsened by stress. A Harvard Health article says reviews suggest different types of psychotherapies may help ease persistent gastrointestinal distress. Using your own stress management techniques can also help - you could try prioritising time for self care, meditation, exercise and movement, or breathing techniques.
4. Change your diet
Emerging research suggests a diet higher in processed foods may be causing intestinal dysbiosis (unbalanced gut microbioata), and that unprocessed food that is lower in sugar may be more beneficial for gut health. While researchers aren't sure which fermented foods may help, a comparison of diets across geographies shows Asian diets, which have a tradition of fermented foods, appear to lead to better gut health.
Among the fermented foods you might try are probiotic drinks such as kombucha, probiotic yoghurts; or fermented vegetables like sauerkraut or kimchi.
5. Manage your use of antibiotics
According to a Spanish study, the biodiversity of bacteria in the gut microbiota decreases during antibiotic treatment. You could try probiotics after antibiotic treatment to restore the balance of healthy bacteria.