Gut Instincts: Illuminating the Link Between Gut Bacteria and Mood Regulation

The human body functions as a sophisticated ecosystem, where diverse systems interact and impact one another. New research has revealed the intricate relationship between the brain and gut. Shedding light on the trillions of microorganisms residing in our digestive tract ; playing a crucial role in influencing not only our physical health but also our mental well-being, sparking a growing interest in the field of neuroscience.

The gut microbiota, composed of trillions of bacteria , such as viruses, fungi, and other microorganisms, create a diverse community in the gastrointestinal tract. Collectively known as the gut microbiome, these microorganisms play a huge role in nutrient absorption, digestion and overall immune function. However, emerging research has also shown that the gut microbiota has a big impact on our mental health and mood. With Increasing evidence associating  gut microbiota to gastrointestinal diseases. Inflammation of the gut has been shown to be linked with causing some mental illnesses, including, but not limited to anxiety, schizophrenia, and autism ^1. The gut microbiota helps regulate inflammation by influencing the production of anti-inflammatory compounds and maintaining the integrity of the gut barrier.

The communication between the brain and gut occurs via the gut-brain axis. This is a bidirectional communication system, which connects the central nervous system with the enteric nervous system in the gut. This communication enables the brain and gut to influence each other, by involving neurotransmitters. Neurotransmitters serve as chemical messengers facilitating the transmission of signals between nerve cells, impacting psychological functions. The gut microbiota is actively engaged in synthesizing neurotransmitters such as dopamine and serotonin. These vital neurotransmitters play an important role in regulating mood, emotions, and our body's response to stress ^2.

Serotonin, commonly known as the "feel-good" neurotransmitter, plays a pivotal role in central nervous system development and function. Remarkably, 95% of the body's serotonin is produced in the intestine, where it exerts hormonal, autocrine, paracrine, and endocrine actions. ^3. This statistic sheds light on the predominant role of the gut in serotonin production.

The concept of the gut-brain axis was initially put forth in a study by Sudo and colleagues, where they identified an impaired stress response in germ-free mice. Subsequent studies involving germ-free mice affirmed the existence of the gut-brain axis ^4.These investigations have highlighted the web of connections within the gut-brain axis and immune pathways.

Diet is a profound factor in the shaping of gut microbiota. A diet high in fibre and prebiotics will promote a healthy gut microbiome. Leading to a positive  mental health. Contrastingly, diets high in processed foods with low nutrients may contribute to dysbiosis. This is an imbalance in the gut microbiota associated with negative effects on mood.

The growing  evidence which highlights the intricate connection between gut, bacteria and mood underscores the importance of considering the gut-brain axis in the pursuit of mental well-being. Maintaining a healthy gut microbiota via a balanced diet and healthy lifestyle choices may potentially prevent or even manage mood disorders. As research in this field continues to unfold, harnessing the power of the gut-brain connection might open new pathways for mental health interventions.

By Jasmine Kaur Chahal

References

Dinan TG, Stanton C, Cryan JF. Psychobiotics: a novel class of psychotropic. Biol Psychiat2013;74:720-6Carabotti M, Scirocco A, Maselli MA, Carola S. The gut-brain axis: interactions between enteric microbiota, central and enteric nervous systems. Ann Gastroent 2015;28:203-9.Gershon, M. D. (2012). 5-Hydroxytryptamine (serotonin) in the gastrointestinal tractNeufeld KM, Kang N, Bienenstock J, Foster JA. Reduced anxiety-like behavior and central neurochemical change in germ-free mice. Neurogastroent Motil 2011;23:264, e119