You depend on your gut microbiome for good physical health. Those legions of bacteria, yeasts, and fungi living in your digestive tract process food for you, supplying you with energy and nutrients. Now new research suggests those microscopic creatures can have a dramatic impact on your mental health as well.
What Is Your Gut Microbiome?
Your gut microbiome is that huge collection of microscopic organisms that make their home in your digestive system. These organisms, one hundred trillion of your closest friends, break down the foods you eat and work with the linings of your small and large intestines to pass fuel and nutrients into your body. You depend on these to sustain you, just as they depend on you to keep them alive. But these organisms do more than simply supply fuel and building blocks for your body. They can also have profound influences on the endocrine system, causing dramatic shifts in hormones throughout your body and brain.
And this process may work both ways. Neuroscientist John Cryan of the APC Microbiome Institute in Cork, Ireland has been studying the human microbiome since 2009. His research has shown that animals which suffered severe emotional trauma early in life had less diversity in the flora in their guts than those which experienced no trauma. This suggests two things: first, we may be able to treat mental illnesses by improving the growth of the right kinds of gut flora. And second, we may be able to diagnose mental illnesses by testing for certain species of flora in the gut.
How Your Diet Influences Your Gut
Because the gut microbiota can influence mood, researchers are looking at ways our food choices impact it. A victim of depression may, for example, need to make dietary changes to improve mood. High sugar content can increase depression, because sugars cause certain bacteria to grow that change levels of hormones such as serotonin in the bloodstream. Cutting back on sugary foods in favor of vegetables can cause healthier bacteria to flourish at the expense of those that prefer to feed on refined sugars.
One branch of research is looking at the use of prebiotics. These differ from probiotics which introduce specific types of bacteria into the gut. Prebiotics are fibers that are not digestible to humans but which bacteria in the gut love. So, with the right types of prebiotics, we can encourage the growth of a range of beneficial bacteria. Early research at the University of Oxford shows promising results in giving test subjects prebiotics, then studying how their mood changes.
Your Gut Microbiome, And How To Improve Your Mental Health
Your gut is an ecology. The organisms found here feed on whatever passes through from your stomach. And of course, those that thrive are the ones best suited to the nutrients and sugars they encounter. Think of this on a larger scale. Animals best suited to eating grasses – such as sheep or cattle – will thrive in a plain, while animals better suited to eating leaves thrive better in a dense forest. If the environment changes from grassland to forest, the animals that can survive change also.
The bacteria and other organisms in your gut change depending on your diet. A diet high in sugars promotes gut flora that love sugars. But suppose you shift to a diet involving dark green vegetables. These bacteria and yeasts that love sugars will find your gut a less hospitable place, while those bacteria that love green vegetables will begin to flourish. Gut flora that love sugars have been linked to depression. Flora that love vegetables and fruit have been linked with much more beneficial states of mental health. So, as your mother told you when you were young, it’s important to eat your vegetables.