Did you ever realize that your gastrointestinal tract or gut health can impact your mood way more than you can imagine? It is sometimes described as our “second brain” and that is because it is controlled by its own complex nervous system that comprises billions of neurons. The bugs in our gut play an important role in the production of neurotransmitters, which affect the way we think and feel.

The impact of gut bacteria imbalance

Our gut produces nearly 90% of the body’s serotonin-“happy hormones”. An imbalance of bugs leads to a disparity in neurotransmitters and can contribute to mood disorders like anxiety and depression. This imbalance is created due to an infection/parasite or frequent consumption of antibiotics or lack of healthy diet and lifestyle, which can lead to too many harmful secretions and not enough healthy ones. 

Microflora, which is comprised by the fungi, viruses, bacteria and other microorganisms actually outnumber your body's cells from 10 to one, and it is apparent that these small organisms play an essential role in your physical as well as mental health. In a study at UCLA researchers have confirmed the effect of microflora on our brain function and have discovered that probiotic microflora (good bacteria) played a positive role in addressing it.

Dr Kirsten Tillisch, clinical instructor of digestive diseases and gastroenterology at UCLA said, "Researchers have known that the brain sends signals to your gut, which is why stress and other emotions can contribute to gastrointestinal symptoms. This study shows what has been suspected but until now had been proved only in animal studies: that signals travel the opposite way as well. Time and time again, we hear from patients that they never felt depressed or anxious until they started experiencing problems with their gut"

Research Study:  A study involved 36 women aged between 18-55 years and split them into 3 groups:

• First group was the treatment group that consumed yogurt two times each day consisting of several probiotics, which seemed to have a good effect on the health of the intestines. This was followed for 30 days.
• The second group consumed a "sham" product that tasted and appeared like the yogurt but was comprised of no probiotics
• The third control group did not consume any probiotics

Pre and post one month of the study, participants' underwent fMRI (functional magnetic resonance imaging) scans while resting as well as in response to an emotion-recognition task.

The women who consumed probiotic yogurt had lesser activity in two brain regions that curb processing of sensation and emotion as compared to the control group.

• The insular cortex that plays an essential part in functions usually connected to emotion that includes (motor control, perception, self-awareness and cognitive functioning).
• The somatosensory cortex that plays an important part in your body's ability to sense  various forms of sensations

In a state of rest, the brain scan showed that the treatment group had higher connectivity between a region known as the "periaqueductal grey" and areas of the prefrontal cortex linked with cognition. On the other hand, the control team demonstrated higher connectivity of the periaqueductal grey to emotion as well as sensation-related areas.

How the bugs in your gut alter your brain?

Researchers were amazed to discover that the effects of brain could be observed in many parts that also include the sensory processing and not just those linked with emotion. Tillisch said that studies have indicated that eating probiotics played a role in the composition of the gut flora especially in those individuals who ate foods rich in fiber as compared to people who ate more typical carb and fat rich western diet.  Green leafy vegetables like spinach help promote good gut bacteria. A latest study discovered sugar molecules, available in spinach, produces the same protective effect on the gut as a probiotic by feeding good gut bacteria.

How your brain affects your gut?

Normally it is believed that their brain is in charge of everything, but it is actually your gut that transmits more information to your brain than your brain transmits to your gut. For instance, you may have likely experienced the visceral sensation of butterflies in your stomach when you are nervous, stressed or angry. The flip side is also true, in that problems in your gut can directly affect your mental health, ultimately resulting in mood disorders such as depression and anxiety.

Neurons are not merely found in your brain, they are also in your gut. These neurons include those that produce neurotransmitters like serotonin, which is also found in your brain. The greatest concentration of serotonin is present in your intestines. Serotonin is linked with depression, mood control and aggression. However, this is one of the reasons why antidepressants, are not that effective in alleviating depression as a healthy balanced diet do

How the gut changes your brain?

A study of about 1000 individuals, conducted for over a year in Sydney,  discovered that nearly 50% of the participants with chronic gut issues were anxious, initially and then developed their gut problems. However, the other 50% developed the gut disorder before affecting the mental faculty. In simple language, their gut seemed to get sick first, leading to brain dysfunction, which was manifested as anxiety, not , the brain dysfunction affecting gut health.