Take care of your gut health now

Not only has the gut microbiome been associated with overall health, emerging research is also associating changes in the gut microbiome to the ageing process, writes Dr Alena Pribyl.

Gut health is an area gaining increasing attention as research on the community of bacteria and other microorganisms that live in our gut – called the gut microbiome – rapidly advances. Not only has the gut microbiome been associated with overall health, emerging research is also associating changes in the gut microbiome to the ageing process. 

We know that low-grade inflammation is one of the most consistent features of ageing, and that this inflammation contributes to the development of age-related diseases such as cardiovascular disease, neurodegenerative disease, arthritis and inflammatory bowel disease. Interestingly, these same age-related diseases influenced by chronic low-grade inflammation have also been associated with the gut microbiome.

Gut bacteria can influence health through the substances they produce

Various diseases that occur both inside and outside of the gut have been associated with the gut microbiome over the last decade. This is because the bacteria in our gut can produce a wide range of substances, some of which are beneficial and others that have been associated with poor health.

Some of these bacterial substances can be transported across the intestinal cell barrier and distributed throughout the body where they can interact with our immune system and influence inflammation.

Beneficial substances, called short chain fatty acids, are produced by our gut bacteria when we feed them fibre-rich plant foods such as whole grains, vegetables, fruits, legumes, nuts and seeds. These short chain fatty acids play many important roles in our health, such as suppressing inflammation, maintaining the intestinal cell barrier, regulating appetite, and stimulating the production of serotonin in the gut.

However, when our gut bacteria are unable to find fibre to eat, they look for other fuel sources such as excess protein or the mucus lining our intestines. When bacteria break down these alternate fuel sources, they produce a wide variety of substances, many of which can promote inflammation.

Studies have observed that once we reach our 30s to 40s, the diversity of bacteria in our gut and the numbers of beneficial bacteria that can produce anti-inflammatory short chain fatty acids tends to plateau. By the time we reach our 50s to 60s, bacterial diversity and the numbers of beneficial species in our gut decrease. At the same time, the bacterial species that are more likely to produce pro-inflammatory substances increase.

However, in an interesting twist, studies that investigated the gut microbiome in long-lived individuals in their 90s and 100s observed the opposite trend.

These studies found that long-lived people continue to have high bacterial diversity and good numbers of bacteria that can produce anti-inflammatory short chain fatty acids. This suggests that the gut microbiome may contribute to healthy ageing and that maintaining a healthy diet full of diverse sources of plant fibres can benefit us as we age.

How to boost beneficial bacteria

To boost the diversity of beneficial, short chain fatty acid-producing bacteria in your gut, it is important to eat a diverse range of different foods that are high in prebiotic fibres. Some examples include chickpeas, lentils, quinoa, cooked and cooled potatoes, brown rice, oats, wholegrain breads, nuts, seeds and a wide range of colourful fruits and vegetables.

As a guide, the suggested amount of fibre to prevent chronic disease is 28g per day for women and 38g per day for men. A recent survey of Australians found that less than 20 per cent of adults meet this threshold.

To discover your own gut bacterial diversity and potential for your gut microbiome to produce anti-inflammatory short chain fatty acids and substances linked to inflammation, you can take an exploratory gut microbiome test.

Dr Alena Pribyl is a senior scientist and research officer at Microba.