Healthy gut, happy mind

There is emerging evidence to suggest that the gut microbiome can also have an impact on our mental health and well-being, writes Dr Praveen Kumar Kaudlay

Remember your childhood days when the family elder would not let you finish your meal without curd rice or a bowl of yoghurt? There is sound scientific logic behind this practice. While the connection between the heart and the mind has been an age-old belief, a similar connection between the gut and the brain is now getting established.

The popular adages, “gut instinct” and “gut-wrenching” are not just aphorisms but are increasingly shown to have a two-way connection between the gut and the brain. Our gut contains trillions of microorganisms and contains over one hundred times more genes than the human genome. These trillions of microbes not only communicate with each other but also communicate with the brain maintaining the finer balance of health in our body.

The gut-brain axis is a complex two-directional pathway of communication facilitated through chemical mediators and the nerves that connect the gut and the brain. The dietary nutrients converted to metabolites in the gut contain fatty acids and chemical substances that have a significant role to play in this gut-brain two-way communication system. When the gut gets damaged, so do the microorganisms lining the gut. It is more evident now that depression, obesity, and various nervous diseases like Alzheimer’s dementia, Parkinson’s disease and autism have an association with the disruption of this gut-brain axis. The gut microorganisms vary according to age and diet. Foods consumed influence the change in the gut microbial composition. Europeans significantly differ from other ethnic groups due to their difference in their daily diet according to one study.

Incidences of irritable bowel syndromes (having diarrhoea and constipation issues with abdominal bloating), and gut infection with a bug called Clostridium difficile that causes nasty diarrhoea in the hospital setting is more common among the Western population as compared to the Indian population.

Western-style diet, which has more saturated fats with low amounts of fibre, have been associated with metabolic diseases like obesity and diabetes mellitus. Such a diet has also been resulting in the alteration of the gut microbial composition. The usage of antibiotics has also been increasing across the world — and more in India where there are no stricter regulations for antibiotic usage. The above-cited reasons have been damaging the gut microbes. Clostridium difficile-related diarrhoeal illness is a significant burden of morbidity and hospitalisations in the West. Often, it becomes more difficult to eradicate the spores of the bug from the gut. The US FDA has recently approved the usage of donor faecal samples which are screened for potential infections to be used as implantation in those suffering from this infection.

The recent Covid-19 pandemic also caused a depletion of good microbes from the gut. The disruption of the gut microbes from the Covid virus and other bacterial, viral, and fungal infections in turn led to the dissemination of harmful bacteria into the bloodstream causing life-threatening infections that the medical fraternity witnessed during the pandemic times.

Now, research is focusing on the role of prebiotics which contains selectively fermented ingredients that can result in changes in the gut microbiota. This aspect of prebiotics has been tried to manipulate gut microbes to address obesity and neurological disorders.

It is noteworthy to mention here that the traditional Indian health system Ayurveda heavily emphasises the dietary aspect in addressing health and diseases. The latest scientific evidence underscores the importance of adhering to a healthy and nutritious diet to maintain healthy gut microbes that are there for a purpose — the disruption of them seems to be resulting in imbalances and in turn, diseases.

The near-mandatory use of yoghurt and products with yoghurt and other fermented ingredients (including buttermilk) in the Indian diet has the medicinal value of constantly replenishing the good microbes like lactobacillus and other microbes to maintain a healthy gut and in turn a healthy mind.

(The author is a consultant haemato-oncologist with a special interest in stem cell transplantation at Royal Wolverhampton NHS Trust, UK. He can be reached at [e-mail])