Research on the gut-brain axis and intestinal microbiota has gained significant momentum in recent years. Nevertheless, this field is not entirely new to medical professionals and researchers. Historically, both practitioners and patients have focused on the gastrointestinal system to uncover the origins of various physical and mental health issues. The understanding of the gut-brain axis and the associated therapeutic strategies has evolved in tandem with advancements in medical practices and societal changes.

Introduction

The human microbiome and its connection with the central nervous system has recently become a highly popular subject. The influence of bacteria on our emotions or behaviour was observed and led to discovery of the so-called gut-brain axis . The neuroactive substances secreted by the bacteria, such as neurotransmitters, short chain fatty acids or amino acids, might influence our behaviour, emotions, cognition, and pain management .

Our ancestors observed that there was a link between digestion and emotions, mood, and behaviour. The faecal transplant has been used in Chinese traditional medicine since the Dong-jin dynasty and in Ancient Greece . The transplantation was also researched in 17th century by Fabricius Acquapendente .We can observe usage of milk products as a remedy for gastrointestinal problems in the works of Hippocrates, Avicenna, Galen, and Pliny the Elder, and the Bible.

Moreover, 18th century vitalists were the ones who began to look at the possibility of an intestinal-brain axis in a more systemic way. In the 19th century, physicians tended to blame the gastrointestinal system for its influence on mind. In the 20th century, scientists approached the issue with the opposite perspective, believing that it was the mind that was responsible for abnormalities in gut activity . In the 21st century, modern methods of research have helped to revive the subject of the gut-brain axis and the role of microbiota in this system

The second brain: understanding the gut-brain axis

The idea that the gut is our "second brain" is not just a metaphor—it’s backed by science. The gut contains millions of neurons and communicates closely with the brain, influencing mood, immunity, digestion, and overall health. This complex network is called the gut-brain axis (GBA). Understanding how it works can help us improve our well-being through diet, lifestyle, and natural therapies.

What is the gut-brain axis?

The gut-brain axis refers to the bidirectional communication between the gut and the brain, primarily through the vagus nerve, hormones, and gut microbiota. It helps regulate digestion, emotions, and cognitive functions.

Key players of the gut-brain axis

  • Enteric nervous system (ENS): often called the "second brain," the ENS consists of about 500 million neurons in the gut, controlling digestion independently but also communicating with the brain.

  • Microbiome: the gut houses trillions of microbes that influence brain chemistry by producing neurotransmitters like serotonin and dopamine.

  • Vagus nerve: this cranial nerve acts as a direct hotline between the gut and the brain, transmitting signals about gut health and inflammation.

  • Neurotransmitters & hormones: the gut produces around 90% of the body's serotonin, impacting mood, appetite, and sleep. Other chemicals like GABA and dopamine also play a role in mental health.

How the gut affects mental and physical health

  • Mood and mental health: a balanced gut microbiome can help prevent anxiety, depression, and stress by regulating serotonin and dopamine levels. An imbalance in gut bacteria (dysbiosis) is linked to mental health disorders.

  • Immunity and inflammation: about 70% of the immune system is located in the gut. A healthy gut reduces chronic inflammation, which is linked to autoimmune diseases, allergies, and even neurodegenerative disorders like Alzheimer's.

  • Digestion and metabolism: a well-functioning gut helps digest food, absorb nutrients, and regulate weight. Poor gut health may lead to IBS, bloating, constipation, or obesity.

  • Cognitive function: gut bacteria influence brain function and memory. Studies suggest that a healthy gut may lower the risk of neurodegenerative diseases like Parkinson’s and Alzheimer’s.

Indian diet and the gut-brain axis

Traditional Indian foods naturally support gut health due to their high fermented content, spices, and fiber-rich ingredients. Here are some powerful foods:

  • Fermented foods: curd, buttermilk, dosa, and idli contain probiotics that enhance gut flora.

  • Fiber-rich foods: lentils, whole grains, and vegetables feed beneficial gut bacteria.

  • Spices: rurmeric, ginger, and black pepper have anti-inflammatory and gut-healing properties.

  • Ayurvedic herbs: triphala, ashwagandha, and brahmi support digestion and mental clarity.

How to improve your gut-brain connection

  • Eat a Gut-Friendly Diet: Consume probiotics (yogurt, kefir), prebiotics (bananas, garlic, onions), and fiber-rich foods to nourish gut bacteria.

  • Manage stress: practices like yoga, meditation, and deep breathing reduce stress, benefiting gut health.

  • Stay hydrated: drinking enough water aids digestion and maintains a healthy gut lining.

  • Exercise regularly: physical activity promotes gut diversity and enhances the gut-brain axis.

  • Get enough sleep: poor sleep disrupts gut bacteria, affecting mood and digestion. Aim for 7-8 hours of quality sleep.

  • Avoid processed foods & antibiotics: these disrupt gut microbiota, leading to imbalances and inflammation.

Conclusion

The gut-brain axis is a crucial link between our digestion, emotions, and overall health. By making simple dietary and lifestyle changes, we can enhance this connection, leading to better mental clarity, immunity, and vitality. Incorporating Indian superfoods and holistic practices like yoga can further strengthen gut health, helping us achieve optimal well-being.

By understanding and nurturing our "second brain," we unlock the potential for a healthier body and mind.