Why eating more plants is vital to our physical and mental health.

Last week Netflix released a new documentary entitled "Hack Your Health: Secrets of Your Gut", featuring doctor and author Giulia Enders, researcher & author Tim Spector, microbiologist Justin Sonnenburg, microbiologist Erica Sonnenburg, neuropsychologist Annie Gupta, microbial ecologist Jack Gilbert, and microbiologist Asshish Jha.

Why our microbiome matters.

Guilia Enders explains how ultra-processed foods are absorbed so quickly by the stomach and the small intestine, that this sort of digestion can be described as a “stressful event” where the body has to quickly deal with a big surge of sugar in the blood. In comparison, by eating fruits and vegetables with a good amount of dietary fibre, the process of digestion is more measured, and there is more material for the microbes that live in our gut to feast on. This is important, because the majority of microbes that live in our gut are very beneficial to us; they help to digest food, they help to quiet inflammation, to train our immune system, to regulate our hormones, and they communicate with our brain to help us determine whether we are full or not, amongst many other things.  

How do people inherit their microbiome?

Everyone is largely born without any microbes on their skin or in their organs. Microbes colonise your skin and insides once you come into the world. Scientists have found that the mix of microbes that will inhabit you is shaped by choices and events in your life from the moment that you are born. Who you kiss, what you eat, where you have travelled to, whether you have pets, whether you’ve experienced stress, and many other minor details of your life will ultimately shape which microbes live on and inside of you. Everyone has a different composition of microbes, but no one is stuck with their present ecosystem. It can be easily changed through changes to your diet and lifestyle. What experts have found is that in the industrialised world, people tend to have an overall reduced biodiversity of microbes due to things like a relatively simple (not a great variety of plants) diet, little access to Nature, stressful work, being born by c-section, excessive sanitation, and the overuse of antibiotics.

How can you change your microbiome for the better?

The big conclusion here is that the most important factor in determining the diversity of your microbial community is your diet. Giulia Enders compares a healthy microbiome to a healthy, biodiverse forest, saying “…you can’t put a few healthy plants in it and expect it to change. A forest needs a healthy balance where the plants and the life can be ok with the circumstances; with the light, with the water, with the nutrients from the soil, and function together.” By comparison, gut microbes only require a relatively small amount of dietary fibre from fruits and veg each day to survive and thrive. According to the microbiome experts, it seems as though an optimal amount of fibre would be around 50g or more per day, which is considerably more than what most people tend to manage. Typically, ultra-processed foods (which form a disproportionately large share of our plates) have little to no dietary fibre. Tim Spector says the key is to eat as many different types of fruits and veggies as you can get on your plate. The more biodiverse your microbial community, the more diverse your gut microbiome is, and the more able it will be to effectively respond to external forces which might affect your health.

What happens if you don’t eat enough dietary fibre?

As Justin Sonnenburg says, “if you’re not feeding your gut microbes enough dietary fibre, your gut microbes will start eating you”. Giulia Enders goes on to explain that there is a protective mucous lining in between the intestines and the bloodstream which allow nutrients to be absorbed but doesn’t allow the microbes to pass through. However, if they run out of things to eat, they tend to start eating the mucous lining, therefore ending up in areas of the body that can cause chronic inflammation and autoimmune disease set-on. Finally, they advise to slowly introduce a greater variety of plant foods, if your diet has been restricted, or not so diverse in terms of the number of plants that you eat per day or per week, to gain a more diverse gut microbiome.  

How to get more fibre into your diet - NHS (www.nhs.uk)