The Gut-Brain Connection: How Does One Affect the Other?

(Reporter: Anoushka Rajesh Video Editor: Prashant Chauhan Senior Editor: Vaishali Sood)

Have you ever had to rush to the toilet before a big exam?

Has stage fright ever made you actually throw up?

Whether it's the ‘butterflies’ in our stomachs when we fall in love, the ‘gut-wrenching experience’ of losing someone we love, or simply a ‘gut feeling’, our feelings have always been tied to our stomachs.

However, it's only recently that we have begun to understand the extent of this connection.

Just how strong is the link between the gut and the brain? Can the health of one affect the other? FIT speaks to Dr Ashwini Setya, Gastroenterologist and Programme Director, Max Super Speciality Hospital, Delhi, and Dr Sanjay Gupta, Internal Medicine Specialist, Bangalore, to find out.

The Mice, the Microbes, and the Mental Connection

Our bodies are made up of a complex web of interconnected, interdependent systems. And until recently, this was thought to be a top-down system. That is, the brain sends its signals and the rest of the body follows.

But recent research shows that this isn’t really the case.

It all started In 2004, with a study conducted on two types of mice. One group had all their gut microbes removed, and the other didn’t. These mice were then placed in a stress-inducing situation.

The result was that the germ-free mice showed a much stronger response to stress as compared to the others.

This experiment would go on to become one of the first to establish a direct connection between our gut microbiome and our brain functioning.

Not just in mice, but in humans too.

Our bodies have a  whole ecosystem of millions of microbes known as the microbiome, most of these reside in our gastrointestinal tracts. The DNA of these microbes actually outnumber our Human DNA!

This also means that a lot of what makes us unique individuals is actually the doing of these microbes.

Since this study, a growing body of research focused on the gut-brain connection has revealed just how interlinked the two are. For instance, recent studies have found that around 50% of our dopamine and more than 90% of our serotonin is actually produced in the stomach.

Our guts also produce more than 30 neurotransmitters and have more nerve endings than our spinal cord, which not only means that it is extremely sensitive to our mental state, but also that it can make or break our mental state.

The line of communication between the gut, the microbes in the gut, and the brain using biochemical signals is called the gut-brain axis.

“The enteric nervous system is there, and there is the central nervous system. Between the two there is a link. And with help of that link, the axis that is created is called the ‘gut-brain axis’.”

Dr Ashwini Setya, Gastroenterologist Max Super Speciality Hospital, Delhi

This could explain why anxiety messes with our stomachs, or why disruption in the gut microbiome affects our brain’s functioning and causes seemingly unrelated ailments.

“Very many times, as a gastroenterologist, I see patients and they say that there is a problem in the tummy and because of that problem, which is usually denoted as gas, they develop a headache,” says Dr Ashwini Setya.

“We have so far been dismissing this. But now we know that there may have been a connection, and this could be because of dysbiosis, or a change in the microbiome of the gut,” he adds.

What Causes Dysbiosis?

• Processed foods containing emulsifiers

• Stabilizers and other chemicals

• Foods treated with pesticides

• Over sanitising

• Stress

Yes, stress.

When we are stressed or anxious, our body releases cortisol which triggers our sympathetic nervous system into action.

What this means is that our body prepares itself to combat the stressful situation, and in doing so it puts a halt on the ‘rest and digest’ system.

So when your body is in the fight or flight mode— whether from stress, anxiety, or even fear, food is broken down slower and isn’t properly absorbed.

This means that stress messes up your gut which messes up our hormones causing more anxiety and stress which further affects your gut.

But, just knowing that this cycle exists might also be the answer to breaking out of it.

“If you don’t have absorption and you have a feeling of bloating, that means either your stress hormones are not allowing you to fight properly. And if it goes on for long, that means you’re continuously exhausting your stress hormones.”

Dr Sanjay Gupta, Internal Medicine Specialist, Bangalore

“Irritable bowel syndrome. IBS, or irritable gut, is very common, and sometimes it can be anxiety related,” he says.

Dr Gupta goes on to explain, “and instead of going for medication, what I've seen in my patients, at least I feel that, if I regulate the intestinal absorption by giving them prebiotics or probiotics, which itself will contain more B12, and more B complex vitamins, it helps.”

“So I personally have experienced this with my patients who have no pre-existing illness, that I can get away with giving them a good vitamin supplement which has got a balance of nutrition, a balance of vitamins like magnesium, selenium, B12.”

Dr Sanjay Gupta, Internal Medicine Specialist, Bangalore

How Can You Ensure a Healthy Gut-Brain Axis?

For a healthy gut-brain axis, we have to first start with a healthy gut and a healthy brain.

• Remove toxic foods that cause inflammation from your diet.

That’s processed foods, alcohol, and foods you may be allergic to like gluten or dairy. Replace them with foods high in fibre like whole grains, and legumes that help lower inflammation.

• Have probiotics like yogurt, lassi, and fermented foods like Kombucha and Kefir that help the gut microbes grow.
• You might also need to add back lost digestive enzymes with fruits like pineapples, papayas, mangoes, bananas, or even with the help of supplements.
• Repair your gut lining. Fish oil, the amino acid glutamine, and antioxidants like Vitamin A, C, E can help with this.
• And lastly, Rebalance your mind and body with conscious lifestyle choices.

This includes getting adequate sleep maintaining sleep hygiene, getting regular exercise, especially cardio, and managing stress. Set aside time for relaxing activities like meditation, yoga, or a calming hobby.

Because as it turns out, it's not just your heart, but the way to your brain is through your stomach too!