By Sakuni Weerasinghe
Ever wonder why people characterise recent experiences in the country as ‘gut-wrenching’? Have you ever felt nauseous reading the news titles these days? These expressions and experiences linking mood and gut point toward something we often overlook: the gut-brain axis.
The diverse population of microbes that live in your gastrointestinal (GI) tract, which is often referred to as the microbiota, plays a significant role in the health of your gut. The intestinal microbiota has recently been associated with the neuro-endocrine-immune pathways leading researchers to explore the concept of a gut-brain axis. This, of course, stemmed from the work of an army surgeon who identified intestinal function as related to mood. As we now know, about 60% of individuals with anxiety and depression report intestinal function disturbances such as Irritable Bowel Syndrome (IBS). Many
others under stress complain of constipation, diarrhoea, bloating, or an upset stomach. These findings further solidify a connection between our gut health and our mental health and vice versa.
Our gut is sensitive to emotion. Feelings of anger, anxiety, and sadness that we are currently experiencing can bring about symptoms related to our GI tract. This can be related to the finding that acute stress activates the hypothalamic–pituitary–adrenal (HPA) axis which prompts the release of cortisol – our stress hormone. Chronic stress (continuous or frequent exposure to stressors) then impedes our immune function and disturbs the balance in the microbiome. These changes in the microbiota then affect mood through the HPA axis. With increased cortisol levels, there are increases in anxiety levels, intestinal movements, and microbiota changes. Can you now see why you would feel nauseated as you read about the rising prices of goods each week? The current research thus points to the fact that these symptoms are not ‘all in your head’ and that stress indeed affects the movements in the GI tract. What’s important for us to know though, is that the HPA axis has a bi-directional regulatory role with respect to the gut-brain axis. This is to say that intestinal microbiota can also inhibit the increase of cortisol, thereby providing relief from anxiety and depression.
Other links of the gut-brain axis point to the role of microbiota in secreting different kinds of neurotransmitters, for example, acetylcholine and dopamine which regulate memory, attention, and mood. Therefore, some changes in neurotransmitters may actually be the doing of intestinal microbiota rather than the stressor itself. The brain-derived neurotrophic factor (BDNF) has also been implicated to help mood disorders as it serves to repair and protect healthy brain cells. Adequate levels of BDNF have also been linked to protection from neurodegenerative diseases such as Alzheimer’s and Parkinson’s. Research studies where the administration of prebiotics has led to an increase in BDNF in the hippocampal region of the brain, point to the utility of incorporating prebiotics (listed below) into our diets.
Surely our gut cannot do maths or memorise Newton’s laws, but if it in any way communicates with our brain as the research suggests, it is more than enough evidence for us to start taking care of it, don’t you think? After all, these findings have led medical professionals to look at alternatives such as the possibility of moods bringing about gut issues thereby providing a basis to prescribe certain antidepressants for conditions such as IBS. It is because of these findings that mental health professionals have too investigated mind-body therapies such as cognitive behaviour therapy.
So how can you protect your gut health?
- It is important to maintain the balance of your microbiota which means the first step is essentially eating a well-balanced diet. This would include foods with probiotic and prebiotic ingredients that support microbial health. Probiotic food can include yoghurt, kimchi, and apple cider vinegar. Prebiotic foods which are composed of dietary fibres can include leeks, onions, garlic, cabbage, whole grains, and oats.
- There has also been evidence for the utility of Omega-3 polyunsaturated fatty acids which have an impact on our cardiovascular system as well as gut health.
- The Mediterranean diet, which is rich in vegetables, fruit, nuts, seafood, unsaturated fats, and vegetable oils, and low in refined sugars and processed food have been shown to increase the diversity of gut microbiota. Since each person’s microbiome is unique, it helps to consult with a professional on what diets are best suitable for their unique needs.
- Practise mindful eating habits, for example taking time to pre-plan your meals and taking time to savour your food.