The profound connection between our brain and gut, known as the gut-brain axis is one of the most exciting and revolutionary discoveries in neuroscience. This sophisticated connection links emotional and cognitive centres of the brain with our digestive system. The research shows that the microbiome-trillions of bacteria, viruses, and fungi in our intestines- can significantly influence our mental health in addition to our physical health. This fascinating connection paves a way for innovating future treatments of psychiatric and neurological disorders.
The Gut-Brain Axis: A Two-Way Highway
The gut-brain axis is a bi-directional communication system. The brain and the gut constantly send signals to each other. Several pathways mediate this connection. The first one being the Vagus nerve that serves as a telephone line between the gut and the brain. It sends signals about the digestive system directly to the brain, playing a major role in regulating emotions and stress responses. The gut also produces neurotransmitters, such as serotonin, and uses them to regulate mood and emotion. The immune system comes up next in the list with about 70% of the body’s immune cells are in the gut. Inflammation is their mode of communication; gut inflammation as a result of imbalance of microbiome can lead to brain inflammation, causing conditions like depression and anxiety. Metabolites, such as short-chain fatty acids, produced by the gut bacteria, can influence the brain function as they promote neurogenesis and protect the brain.
The Microbiome’s Role in Mental Health
The gut microbiome is a complex ecosystem made up of hundreds of species of microorganisms that play vital roles in digestion, immune function, and metabolism. Recently, scientists uncovered another crucial role: influencing the brain and mental health. Studies have shown a strong link between an imbalanced microbiome called dysbiosis, and mood disorders such as depression and anxiety. The imbalance occurs when the proportion of beneficial bacteria to harmful bacteria shifts, triggering inflammation and stress in the body that affects the brain. This observation is supported by the lower levels of certain good gut bacteria like Lactobacillus and Bifidobacterium. These are known to produce mood-regulating neurotransmitters like serotonin and dopamine.
Dysbiosis can activate the stress response in the body, leading to overproduction of cortisol which is the primary stress hormone. Chronic stress results in damage to the gut lining, leading to compromised health of both gut and the brain. Studies show a direct relationship between digestive health and mental-health, as people with severe gut symptoms often showcase higher levels of anxiety. Similarly, individuals with autism spectrum disorder (ASD) experience gastrointestinal issues owing to the difference in their microbiome composition as compared to normal individuals.
Can Good Bacteria Make You Happier?
With the newfound emphasis on the role of gut bacteria, one might wonder how to improve the quality of gut microbiome. Ongoing studies show that probiotics can be a helpful addition to the diet. Probiotics have shown positive effects on mood and anxiety by enhancing the diversity and health of the gut microbiome. Probiotics, including Lactobacillus rhamnosus and Bifidobacterium longum, are strains of bacteria. They are known to influence mood and the production of neurotransmitter GABA that calms down the nervous system hence reducing anxiety.
However, probiotics only serve as an addition to the main diet. The overall diet and lifestyle play a key role in maintaining healthy gut-brain connection. A diet rich in fibre, fruits, vegetables, and fermented foods can promote a diverse and balanced microbiome. Foods such as curd, buttermilk, pickles, idli/dosa contain natural probiotics that help nurture beneficial gut bacteria. Highly processed foods such as sugar, and unhealthy fats promote dysbiosis, increased inflammation and mental health issues.
The Future of Mental Health Treatments: Microbiome-Based Therapies
The eye-opening research about the role of gut microbiota on mental health comes with exciting novel treatments for mental health disorders. In future, microbiome-based therapies will be designed to improve mental well-being by targeting the gut. Personalised diets will be in fashion. According to the health of an individual’s gut microbiota, diets will be recommended to improve the status and mental health by extension. Another possibility includes psychobiotics supplements. These are specific strains of probiotics that directly influence the brain. The supplements will be tailored to individual needs, offering a personalised and novel way to treat depression, anxiety, and other psychiatric conditions without any side-effects, all while improving and maintaining excellent gut health.
Thus, the gut-brain axis challenges our traditional view of the brain as an isolated organ. It acknowledges the interconnectedness of the condition of our gut to the emotional and psychological well-being. In the future, we may find new ways to address and cure psychiatric disorders by targeting gut health. Harnessing the full potential of the microbiome will not only treat the mental health disorders, but also prevent them altogether.
Deeksha, is a Biochemist and an aspiring neuroscientist. Her research interest lies at the intersection of molecular neuroscience and drug discovery.
