Your intestines are lined with microvilli (small hairs), to increase the surface area for greater nutrient absorption. The space between the microvilli provide ideal environment for the gut bacteria to thrive. This bacteria in our gut secrete enzymes that we need for efficient digestion and for us to absorb the nutrients from the food we eat. These enzymes help us to break down proteins, fat, carbohydrates and greens. Bacteria extracts energy from undigested carbohydrates that ferment in the gut and some bacteria also produce vitamins and anti-inflammation compounds.
There are more than 100 million neurons that weave between the muscle layers of our gut. It's roughly the same number of neurons in our brain. If you didn't know then almost 80 percent of the serotonin (feel-good hormone), which is involved in memory, learning, sleep, mood and other interactions in the body, is made my the neurons in your gut and transported to the brain. Your gut and your brain are in constant communication- sending and receiving information via vagus nerve (a communication channel that connects the brain to all organs in your body). The communication that travels between the gut and the brain is called the gut-brain axis.
Gut-Brain Axis
Over 90 percent of the nerve pulses in the vegas nerve that connects the brain with all your organs in the body, are communication from the gut to the brain.
Bacteria in the gut uses the same vagus nerve to communicate with the brain. Gut neurons and gut bacteria actively interact between themselves and their interactions are very important for our health. Gut bacteria produce copies of important peptides that travel via the bloodstream to your brain. These peptides are responsible for altering our behaviour and our emotions. They make large quantities of molecular copies of serotonin, GABA (gamma-aminobutyric acid) and other neurotransmitters- our bodies rely on these bacteria and their secretions for our homeostasis.
Low levels of GABA can result in anxiety, poor focus, issues with long-term memory. If you are severely short of GABA, it could add to ADHD and autism. Gut bacteria help to organise the human nervous system. A deficit can mean increase in stress hormones- which could contribute to onset of depression, addictive behaviours, seizures. In this article you can read how you can support your brain health through food as well as lower anxiety.
Gut bacterial imbalance can affect many functions in our bodies and lead to chronic inflammation that can also lead to damage of the skin microbiome, which contributes to faster ageing.