The complete organ system is interlinked and interdependent. The gut system takes care of the whole process of the digestive system, starting from food ingestion to excretion, digestion, and absorbing nutrition from food. Then the question is, how does it influence the brain? In this article, we will explain how the gut and brain are interrelated. The gut-brain axis refers to the communication pathway between the gut and the brain. As for several studies the gut and brain might even affect one another's well-being. Similarly, gut health has an impact on skin health, which is called the gut-skin axis.
Vagus nerve in Gut-Brain Axis
The gut-brain axis is the term used to the communication network that connects your gut and brain. These two organs are connected in terms of physical and biochemical in numerous ways.
Let’s start with the basics, in your body, neurons are cells found in your brain and central nervous system that tell your body how to respond. There are approximately 100 billion such neurons in the human brain itself.
Whereas your gut contains 500 million neurons, which is quite more than your brain. And these neurons are connected to your brain through nerves in your nervous system.
The vagus nerve is one of the biggest nerves connecting your gut and brain. It sends signals in both directions. Hence, the vagus nerve is important in the gut-brain axis and its role in stress.
In one of the animal studies, it was found that stress inhibits the signals sent through the vagus nerve and also causes gastrointestinal problems. Similarly, one study in humans found that people with irritable bowel syndrome (IBS) or Crohn’s disease had reduced vagal tone, indicating a reduced function of the vagus nerve.
Gut-Brain Axis and Neurotransmitters
Your gut and brain are also interlinked through specific chemicals known as neurotransmitters. Neurotransmitters like serotonin produced in the brain control feelings and emotions. It contributes to feelings of happiness and also helps control the circadian cycle.
Similarly, many of these neurotransmitters are also produced by your gut cells and the trillions of microbes living there. Actually a large proportion of serotonin is produced in the gut. Another neurotransmitter called gamma-aminobutyric acid (GABA), produced in the gut, helps control feelings of fear and anxiety.
Trillions of microbes living in your gut help make such beneficial chemicals that affect the body and brain.
Gut-Brain Axis and Immune System
Gut microbes play an important role in your immune system and inflammation by controlling what is allowed into the body and what is excreted. Inflammation, which is associated with a number of brain disorders like depression and Alzheimer’s disease.
Lipopolysaccharide (LPS) is an inflammatory toxin produced by certain bacteria. If too much enters the bloodstream from the intestines, it might induce inflammation. A leaky gut barrier can allow germs and LPS to enter the bloodstream.
Inflammation and high LPS levels in the blood have been linked to a variety of neurological illnesses, including severe depression, dementia, and schizophrenia. Often, health experts prescribe probiotic supplements along with antidepressant medication to patients.
May be due to all these above reasons Gut is known as the second brain.
Gut-Brain Axis and Probiotics
As discussed above, gut bacteria affect brain health, so definitely, having a healthy gut with good bacteria may improve brain health.
Probiotics are nothing but live microorganisms like bacteria that impart health benefits if consumed. However, not all probiotics are the same. Probiotics that affect the brain are often referred to as "psychobiotics." Some probiotics have been shown to improve symptoms of stress, anxiety, and depression.
One human study with irritable bowel syndrome and mild-to-moderate anxiety or depression found that taking a probiotic called Bifidobacterium longum for six weeks significantly improved symptoms. WonderPro Superprobiotic is a probiotic supplement with Bifidobacterium longum and the other four crucial spores. It requires no refrigeration and is free from preservatives, dairy, sugar and gluten, making it suitable for lactose intolerant, gluten intolerant, non-diabetic and diabetic consumers. Wonderpro Super Probiotics is tested by DIPAS DRDO for use in extreme weather condition.
Prebiotics are typically fibres that are fermented by your gut bacteria. Prebiotics support the growth of good bacteria. Adding fibre-rich foods to your daily diet can provide a good amount of prebiotics.
Foods for the Gut-Brain Axis
A few groups of foods are typically advised for the gut-brain axis.
Omega-3 fats: These lipids are abundant in the human brain and can be found in oily seafood. Omega-3 fatty acids have been shown in both human and animal studies to enhance gut flora and lower the risk of mental problems.
Fermented foods: Yogurt, homemade pickle, paneer, buttermilk and cheese all contain healthy microbes such as lactic acid bacteria.
High-fiber foods: Prebiotic fibres are beneficial to your gut flora and can be found in whole grains, nuts, seeds, fruits, and vegetables. Reduced stress hormones are aided by prebiotics.
Polyphenol-rich foods: These are plant chemicals that are digested by your gut bacteria. Polyphenols increase healthy gut bacteria and may improve cognition. Get it from cocoa, green tea, olive oil and coffee.
The gut-brain axis refers to the physical and chemical links between the gut and the brain. Millions of nerves and neurons connect your gut and brain. Neurotransmitters and other substances produced in the gut have an effect on the brain. Omega-3 fatty acids, fermented foods, probiotics, and other polyphenol-rich foods may improve gut health, perhaps benefiting the gut-brain axis.