Why Microbial Diversity Is The Key To Gut Health

By Carla Oates 

Bacteria are one of the oldest forms of life on earth and scientists have been studying microorganisms for hundreds of years... In high school, you may have learned about the work of French scientist, Louis Pasteur, who, during the late 19th century, discovered that microorganisms cause both fermentation and disease. And since then, researchers have repeatedly shown the trillions of microbes that live inside your body are vital to both your physical and mental health...

While we have been conditioned to think of our microbes as either ‘good’ or ‘bad’ – researchers agree that it’s not quite that simple. There are microbes we want, microbes we don’t want and microbes that can be either good, bad or somewhat neutral – depending on the environment and our relationship to them.

Different people also have different combinations of resident microbes and your gut microbial population is as unique as your fingerprint. Interestingly too, studies have shown people with more microbial diversity are likely to be healthier.

While there are a multitude of factors that contribute to the numbers and diversity of bacteria in our gut – diet undoubtedly has the most profound impact. For example, people who eat what’s classified as the ‘Standard American Diet’ which is high in fat and refined sugar but low in fibre, have been shown to have less microbial diversity.

Conversely, one study found that the gut microbiome of Tanzanian hunter-gatherers was 30 per cent more diverse than those living in urban societies. In fact, researchers discovered some bacterial species in the Hadza people – whose diets follow an annual cycle and change seasonally – that they had never seen before.

What studies like this suggest is that modern humans may have reduced their microbial diversity by eating the same diet all year round. On top of this, processed foods, sugar, refined carbohydrates and taking antibiotics may unnecessarily cause imbalances in our gut microbial populations – which in turn, may negatively impact our gut health.

Why Is Microbial Diversity So Important?

Studies have shown that the magical microbes that reside in your digestive, reproductive and respiratory tracts are involved in many important processes including digestion, immunity, cognition, mood and memory, hormone production, inflammation, sleep, metabolism, bone formation and even longevity. Your gut microbes help to digest most of the food you eat and assist in the production of vitamins, hormones, enzymes and essential amino acids.
They also help to neutralise pathogens. But there is still so much to discover. Scientists still do not fully understand all the ways in which microbes work. Already, many modern diseases – including type 2 diabetes, obesity and inflammatory bowel disease – have been linked to reductions in gut microbial diversity. There is also a growing body of research to show how microbial diversity may help to alleviate symptoms of conditions such as eczema, asthma and allergies, as well as gut health issues. In summary, gut microbes are critical to human health. And really, it’s a case of the more and more diverse the merrier, because different microbes perform different tasks and support our health and wellbeing in a myriad of ways.

Simple Tips To Encourage Microbial Diversity

  • Add probiotic-rich, lacto-fermented foods – such as kimchi, sauerkraut, miso, natto, tempeh, kefir and yoghurt – to your diet as these foods contain gut-friendly bacteria.
  • Keep your microbes happy by feeding them plenty of their favourite foods – prebiotic plant fibre, in the form of fresh fruits and vegetables. Garlic, onions, artichokes, asparagus, leeks, celery, and apples are all good examples of prebiotic foods.
  • Different foods feed different gut microbes – so eating a wide range of foods will encourage a more diverse gut microbiome.
  • Complex carbohydrates such as the resistant starch in bananas, legumes and sweet potatoes also feed beneficial bacteria.
  • Eat seasonally for variety. Shop at your local farmers market or via an organic vegetable delivery service to get familiar with which foods are in season.
  • Avoiding processed foods may also encourage microbial diversity. Animal studies have shown that the emulsifiers used to keep processed foods may disrupt gut microbes and contribute to increased obesity and other chronic inflammatory diseases. While artificial sweeteners used in soft drinks and other processed foods have also been shown to disrupt the gut microbiome in mice.
  • Invest in a water filter to remove fluoride and chlorine which, over time, may have an impact on our inner ecosystem.