Welcome to the second half of the gut series! To recap, last time, we discussed the importance our gastrointestinal tract plays in our digestive system. It runs from our mouths to our anus and includes organs like the oesophagus, the small intestine and the large intestine.The microbiota is like a mini universe in the gut with diverse microorganisms that influence our gut health. More and more studies are showing the influential relationship between our guts and our brains and how their similar make up continues to affect the overall health of our bodies.
There are a minimum of 300 species of microorganisms in our digestive tract and it is perhaps worth pointing out that our gut is part of this complex system. The American Journal of Nutrition stated that ‘a healthy microbiome is more resistant and resilient to disruption... and influences the health of its host (our human body) in a 2019 study. A diet high in processed foods, sodium, sugar and fat tends to damage the good bacteria in the gut whereas, diets high in fibre for instance, do quite the opposite. ‘We must restore our own relationships with gut microbes for gut health’,(TedTalk, 2019) and this can be done, one meal at a time. Perhaps this is what is meant by ‘you are what you eat’.
Referring to the second part of the axis, our brains are the most important organs in our bodies; responsible for coordinating actions and reactions, memories and thoughts. Although they will age just like our bodies, there is much we can do to ensure our brain health is top tier. Heavily influential is what we eat and drink and if we move our bodies or not. We can also train our brains in isolation with activities like meditation. After all it is also a muscle so these all improve cognitive function. In addition, substances like alcohol should be used in moderation and tobacco minimally if at all since these have been linked to cognitive decline disorders like dementia.
Having a wide variety of good gut bacteria has been shown to reduce symptoms of anxiety. This shows there is definitely a link between our gut and our brain. After all, they contain many of the same neurotransmitters. Enter the gut-brain axis which is a link between the central nervous system and the digestive system therefore providing an indirect pathway between cognitive and intestinal functions. These microbes in our gut interact with our brain in many ways. A couple include; the gut hormone which signals where bacterial products produce neuropeptides that enter the bloodstream to directly influence the nervous system. Secondly, there is intestinal permeability where a syndrome like leaky gut can be associated with depression and this supports the hypothesis that gut bacteria can influence the pathology of certain mental disorders. The gut microbiome is so powerful that in a fecal transplant study published April 2020 in the American Association for the Advancement of Science, intestinal microbiota was transferred from a patient suffering from alcoholism and on antibiotics to mice which translated into anxiety and depression in them.
Although studies on this particular relationship are still continuing, a vast amount of research has been done to greatly influence our health and wellness in this regard. Diets high in fruit, vegetables, whole grains, unsaturated fat and prebiotics which stimulate the growth of good gut bacteria, prove to have long lasting health effects on both the gut and the brain. This, coupled with adequate daily exercise and other habits for stress reduction are guaranteed to have positive effects on our gut, our brain, and our entire body. Restricting antibiotic use is also advised due to the reducing effect it has on microbiome diversity.
Next mealtime be sure to think about how your gut- brain axis is affected!