Trillions of bacteria live in our stomach, especially in the gastrointestinal tract. Their actual number is not known, but scientists estimate that they can range from 30 trillion to 400 trillion. These bacteria, called gut microbeta, are not present in the mother’s womb, but as soon as the baby comes out, they reach the intestines through breast milk. Since then, they take the responsibility of digesting food and increasing immunity. They are also called good bacteria.
What is the gut-brain connection
Gut bacteria were initially seen only in association with digestion, but then there was talk of a gut-brain connection. A total of years ago, microscientist Jane Foster was experimenting with two groups of mice in her lab. One group had gut bacteria, while the others did not. Within no time, it was seen that those rats were more upset, which had bacteria in their intestines. They could not take quick decisions and were also more aggressive. Scientists put both groups in a maze and found that the mice with the bacteria were able to find their way out after a long time, while the other group quickly got out.
This experiment, conducted in collaboration with Canada’s McMaster University, for the first time also talked about other functions of food-digesting microbes. They create a kind of brain fog, which makes the mind restless and unable to take quick decisions.
how to reach the brain
Why and how do bacteria living in the convoluted tubes of the intestine affect the brain? Even scientists do not have a definite answer to this at present. Parkinson’s is being seen mostly in the experiments being done on rats. E-coli, a bacterium present in the stomach, makes a protein called curli. This protein activates other proteins, one of which is the protein responsible for Parkinson’s. This process is called protein-misfolding. It is from here that the neurotransmitters of the brain get the wrong signal and the disease starts.
Gut microbes are also believed to be a cause of Parkinson’s and autism. Representational photo (Unsplash)
Increases fear of autism
Regarding autism, it was also found in experiments on rats that gut bacteria are responsible for it to an extent. Due to an infection during pregnancy, the bacteria in the stomach send messages to the T-cells. These are immune cells, whose job is to protect the body from danger. The cells produce immune molecules, which also reach the brain of the fetus and increase the risk of autism.
Vagus nerves become direct hotlines
A research regarding this came in the scientific journal E-Bio Medicine under The Lancet. In research published under the name Microbeta and Gut-Brain Axis, it was told that what is the relation of bacteria found in the intestines to the brain. The vagus nerve acts as a direct route for this, which transmits the signal of movement in the intestines directly to the brain. Gut hormones, such as CCK, Ghrelin and 5-HT are also believed to be responsible for this. However, so far most of the research has been done on rats.
One of the limited human studies took place in 2019 at Oxford University. 71 people suffering from mental illness were divided into two groups. One group was given a probiotic to increase the good gut bacteria in them. The other group got normal food and drink. A month-long study showed positive changes in the mood and state of mind of participants taking the probiotic.