Do you ever notice why people get angry and upset when they haven't eaten for hours? "Hangry" is the term usually associated with such people. Or how good food often makes you happy and you suddenly start being jolly to the point your friends and family are left shocked. Well, this interrelation between your food and mood swings is backed up by scientific research explaining the gut-brain axis.
The gut-brain axis involves the bidirectional communication between your central and enteric nervous systems linking your brain's emotional and cognitive centers with peripheral intestinal functions.
Research on this dates back to 1765, when Scottish physician Robert Whytt introduced the concept of "nervous sympathy" to describe the mechanisms he believed connected the inner body organs. He observed that the gut possessed an abundant supply of nerve endings, which dispensed ‘nervous energy’ throughout the body.
Communication Pathways Between the Gut and Brain:
The brain and gut hold a complicated relationship and work hand in hand to promote a healthy, functioning body. This is achieved by multiple communication pathways present between your stomach and brain. One of these is the vagus nerve; the main nerve of your parasympathetic nervous system. This system is involved in the control of involuntary body functions, including digestion, heart rate, and the immune system.
Amongst chemical messengers, an important one is serotonin, which is believed to regulate feelings including happiness and anxiety. Specific medications known as Selective serotonin uptake inhibitors (SSRI) are often involved in relieving mood disorders by increasing serotonin activity in your brain.
Dopamine is another chemical messenger acting on areas of your brain to give out feelings like pleasure, satisfaction, and motivation. It also plays a key role in memory control, mood, sleep, learning, and movement.
Lastly, GABA, another chemical messenger, is known to produce a calming effect by lessening the ability of a nerve cell to receive, create, or send chemical messages, thus playing a key role in controlling anxiety, stress, and fear.
Impact on Mental Health:
Over the years, scientists have come up with discoveries reflecting the crucial role your digestive system plays in impacting your mental health.Since then, multiple case studies discussing such scenarios have been released. A study conducted by Ander Uitterlinden in December 2022 connected multiple gastric problems with mental health, mentioning how gastrointestinal symptoms are often reported in people with psychiatric illness or how weight and appetite changes are common among people dealing with depression. It also highlighted the heightened risk of nausea, heartburn, diarrhea, and constipation caused by anxiety.
Multiple other case studies mention similar points, for example, a case report on Depression in Ulcerative Colitis and Novel Treatment Approach; it mentions how an altered gut microbiota is recognized for its role in mood regulation and depressive disorders and that disruptances in communication pathways between the gut and brain can contribute to mood disturbances.
Lastly, a case study by Future Learn also mentions how animal and human studies have demonstrated that the administration of specific bacterial strains can contribute largely to reducing the negative effects of stress. The term "psychobiotics" is often used to define substances such as live bacteria that when digested, have psychological benefits.
Diet and the Gut-Brain Connection:
Another very important aspect of this axis is the effect your diet has on your brain. Your food consumption matters a lot and has a great role to play in your mood changes and other brain functions that can be disrupted by unhealthful consumption. Therefore, one must remain mindful of their food consumption for the sake of a healthy, well-functioning body.
Probiotics are often the first line of treatment for compromised gut health, having a significant impact on digestive issues and immune function. But their benefits don't stop here! They play a great role in aiding good mental health as well. Some research has found that probiotics may help boost mood and cognitive function and lower stress and anxiety.
For example, a study published by Frontiers in Aging Neuroscience found that Alzheimer's patients who drank milk made with four probiotic bacteria species for 12 weeks scored better on a test to measure cognitive impairment compared with those who drank regular milk.
Moreover, it should be understood that unhealthy diet consumption not only degrades gut health but negatively influences mental health as well. Sugar and processed food can lead to inflammation throughout the body and brain, which may contribute to mood disorders, including anxiety and depression. Better than this, a diet rich in omega-3 fatty acids or fruits and dark green leafy vegetables guarantees a happy gut and a happy mood.
Innovative Therapies and Future Research:
As science and research have moved deeper into investigating the gut and brain axis, bringing out multiple different types of information and theories, a set of different therapies and research has also been presented to improve gut-brain health. Psychobiotics have seemed to prove beneficial as well by alleviating stress and anxiety by modulating neurotransmitter production, particularly serotonin and GABA. It also plays a role in mood- uplifting and easing depression by modulating the gut-brain axis and neural pathways associated with depression. Lastly, psychobiotics hold the possibility of enhancing cognitive functions and memory by impacting the gut-brain connection and inflammatory responses.
Despite these innovations, research on the matter is still going on with several specialized lab groups working on the development of microbiome-based therapies to ameliorate depression and anxiety caused by stress.
Conclusion:
The gut-brain axis is a detailed network underscoring the profound connection between our digestive system and mental health. By researching more on this and gaining valuable insights into how our gut health influences our mood, cognition, and overall well-being, we can try to maintain a healthy diet. Embracing this holistic view of health can lead to more effective and comprehensive approaches to wellness, enhancing the quality of life for many.
References:
Carabotti, M., Scirocco, A., Maselli, M. A., & Severi, C. (2015, June 1). The gut-brain axis: interactions between enteric microbiota, central and enteric nervous systems. PubMed Central (PMC). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4367209/
Miller, I. (2018). The gut–brain axis: historical reflections. Microbial Ecology in Health and Disease, 29(2), 1542921. https://doi.org/10.1080/16512235.2018.1542921
Professional, C. C. M. (n.d.-b). Vagus nerve. Cleveland Clinic. https://my.clevelandclinic.org/health/body/22279-vagus-nerve
Scaccia, A. (2023, April 17). Everything you need to know about Serotonin. Healthline. https://www.healthline.com/health/mental-health/serotonin#functions
Healthdirect Australia. (2023, October 17). Dopamine. Healthdirect. https://www.healthdirect.gov.au/dopamine#:~:text=Dopamine%20acts%20on%20areas%20of,movement%20and%20other%20body%20functions
Professional, C. C. M. (n.d.-a). Gamma-Aminobutyric Acid (GABA). Cleveland Clinic. https://my.clevelandclinic.org/health/articles/22857-gamma-aminobutyric-acid-gaba
Wapner, J. (2023, March 8). The link between our food, gut microbiome and depression. Washington Post. https://www.washingtonpost.com/wellness/2023/01/31/gut-microbiome-anxiety-depression/
Sharma, A., & Sharma, V. (2023). The Gut-Brain Connection: A case report on depression in Ulcerative colitis and Novel Treatment approach. Curēus. https://doi.org/10.7759/cureus.48462
FutureLearn. (2022, October 25). Updates, Insights, and News from FutureLearn | Online Learning for You. FutureLearn. https://www.futurelearn.com/info/courses/the-human-microbiome/0/steps/170620
Harvard Health. (2023, March 22). Probiotics may help boost mood and cognitive function. https://www.health.harvard.edu/mind-and-mood/probiotics-may-help-boost-mood-and-cognitive-function
Eating well for mental health | Sutter Health. (n.d.). https://www.sutterhealth.org/health/nutrition/eating-well-for-mental-health#:~:text=What%20we're%20not%20always,improve%20concentration%20and%20attention%20span
LifeSciencesIntelligence. (2023, August 15). Enhancing Mental Wellness with Psychobiotics, the Gut–Brain Connection. LifeSciencesIntelligence. https://lifesciencesintelligence.com/features/enhancing-mental-wellness-with-psychobiotics-the-gutbrain-connection Assessed and Endorsed by the MedReport Medical Review Board
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