United States: A recent study which was published in the Cell journal has established that the immune system has a connection with the mental state of an individual through the brain and the gastrointestinal system.
In this research work, the concentration was on a less familiar part of the human digestive system known as Brunner’s glands which resides in the duodenum which is part of the small intestine. It seems that these glands are crucial in to how the stress impacts gut bacteria and immune system.
As reported by PsyPost, there has been much interest in the connection between the brain and the gut especially in the current society. For instance, we understand that psychological stress has an impact of moulding the immune system and increased susceptibility to infections and considering that intra-gut bacteria help to shape the immune system. Less lucid has been how stress and mental condition can influence gut health and thereby the immune system.
Brunner’s glands were specifically targeted in this study because it is well-known that it is responsible for the secretion of mucus which creates a barrier on the lining of the gut.
Past research has established that stress lowers the immune systems in the body, thus decreasing the number of friendly bacteria including Lactobacillus in the gut through which the body is more inclined to infections.
The given glands were expected by the researchers to be a kind of a bridge between the brain and the gut, affected by stress and other psychological factors. “We were interested in identifying how psychological states make the body vulnerable to diseases. This has always been a real biological phenomenon; however, there has not been a mechanism to explain the same.
When we started working on it, we assumed that a neural circuit must connect the regions of the brain that are associated or linked with emotion and the cells in the periphery that are responsible for the defense against pathogens,” mentioned Ivan E. de Araujo, the director.
The study was carried on over one thousand adult male mice. To manipulate the signals from the brain to the gut and vice versa, since the heart has a line of communication called vagus nerve, the researchers employed several techniques to activate or inhibit its function. Some mice’s vagus nerve or Brunner’s glands were partially or completely modified or even excised, to determine the effects of these structures on the gut.
To investigate the possible involvement of the brain, the researchers implicated one region of the brain known as the central nucleus of the amygdala, which has a critical role regarding the emotions, stress and fear.
They provided an outline of the neural circuitry that links this melting pot of the brain to the Brunner’s glands through the vagus nerve, and did it through using complex techniques like gene transplanting, viral infusion, and imaging techniques. Depending on the activation or suppression of these circuits they would be able to immediately study the change in Brunner’s glands, and the bacteria that inhabited the gut.