The Link Between Gut Bacteria and Our Mind
The microbes that live in your gut are directly responsible for how you feel—thanks to the millions of nerve cells that make up your enteric nervous system, also known as your second brain.
“One of the first questions I ask during my therapy sessions is—how does your gut feel?” says Dr Seema Hingorani, a clinical psychologist based in Mumbai. “From Post Traumatic Stress Disorder to mood disorders—around 80% of the patients that visit me are dealing with some kind of gut-related problems and what I’ve come to notice is that people with a history of trauma have a weaker digestive system.” she adds.
Our intestines have an enormous surface area; and the gut microbiome that they house weighs a whopping 2 kg. It might sound meager compared to your body weight, but if you think about it, that’s a lot of microbes living inside of you and they’re constantly using the nutrients and molecules in a way that directly affects your body. The gut-brain axis is a term for the channel that connects your nervous and digestive systems and they’re connected both physically and chemically in many ways.
The strongest link: the vagus nerve
The vagus nerve is one of the biggest nerves in our body and it directly connects our gut and mind—running all the way from the brain to the colon, sending signals in both the directions. According to a study by Dr Sonia Pellissier, assistant professor, Neurosciences and Physiology Applied to Psychology, University of Savoy Mont Blanc, Chambery, France, people with irritable bowel syndrome or Crohn’s disease have a significantly less functional vagus nerve, further proving the fact that it is the vagus nerve indeed that connects our nervous and digestive systems.
Neurotransmitters like serotonin and gamma-aminobutyric acid are actively produced by the microbes living in our gut and they affect both our happiness and feelings of fear and anxiety. “It all comes down to serotonin—our brain produces it and so does our gut; and if the body is having trouble manufacturing it, patients might suffer from irritable bowel syndrome which can ultimately lead to migraines and also mental health-related problems.” Says Hingorani. A study conducted by scientists at the Department of Medical Biophysics, University of Toronto, Canada shows that certain probiotics can increase the production of gamma-aminobutyric acid and reduce depression in laboratory mice.
How it works with the immune system
Gut microbes play a vital role in our immune system by taking charge of everything that enters the body and everything that is later excreted. Lipopolysaccharide is an inflammatory toxin produced by certain bacteria and when the gut barrier becomes weak, it can pass over into the bloodstream—leading to several brain-related diseases. A research conducted by a group of scientists at the Laboratory of Neurogastroenterology, APC Microbiome Institute, University College Cork, Cork, Ireland states that high levels of Lipopolysaccharide in the blood have been linked to disorders like depression, schizophrenia and even dementia.
Achieving a healthy gut and a healthy mind
Probiotics are ‘good’ bacteria, while prebiotics are dietary fibres that are fermented by your gut bacteria—both of which are commonly used to treat the digestive system. “The solution is a diet rich in fibre, polyphenols, natural probiotics and Omega-3 fats. One must also try to cut down sugar and gluten as much as possible. But because both the gut and mind affect each other simultaneously, mental health-related activities like therapy and meditation also play a big role in improving your gut and aiding the production of good bacteria. At the end, it’s all about boosting your serotonin levels by practicing self care,” Hingorani adds.