Neural signals are capable of altering the composition of the bacteria of the intestine – perhaps, to prepare them to give their best in digestion.
Intestine and brain are connected by a double -way road. Not only that, as has been ascertained for some time, intestinal bacteria can influence brain function and mood; The opposite is also true – The brain can directly modulate the composition of the microbiota of the intestine.
According to a study published on Nature Metabolismneural signals manage to alter the population of bacteria that colonizes the digestive tract in just a couple of hours. The suspicion is that they do it to prepare the microbiota for digestive processes.
Activation on command. A group of Augusti Pi scientists The Sunyer Biomedical Research Institute of Barcelona employed a technique called chemogenetics To activate, selectively and with the help of specific molecules, A subgroup of neurons that regulate the appetite in the hypothalamus (a region behind the brain) of 16 mice. The researchers analyzed the intestinal bacteria taken in 4 different sections of the mice intestine after 2 or 4 hours the neural activation. And compared the composition of their microbiota with that of mice that had not received any type of stimulus.
An immediate response (almost). In some sections of the stressed mice intestine, a “flowering” of intestinal bacteria was observed, with a remarkable increase of diversity in their composition. The effect seemed more marked in the duodenum, the final portion of the small intestine: in the mice veterans by chemogenetics, the microbiota was, two hours after activation, five times more varied than the control group. Even when the same as the hypothalamus neurons were inhibited, the composition of the microbiota has changed. Some families of bacteria have thinned 99%, in different sections of intestine and at different times (after 2 or 4 hours) of the experiment.
Keep ready! The signal is thought to be mediated by the hormones that regulate the appetite. When scientists injured them in the brain of the mice, the waterfall of changes in the microbioma was triggered. And it was enough from 2 to 4 hours to multiply or dominate certain bacteria, in different ways depending on the stretch of intestine from which the champion had been taken.
The brain is therefore added to all the other factors (diet, environmental changes, drugs) able to influence the variety of bacteria in the intestine. Perhaps, some populations of neurons respond to hormones that report the arrival of food by preparing the microbiota for digestion.
Much still to discover. The discovery triggers some considerations for those who carry out research on the microbiota. The first is that this can vary significantly within hours, and not just days or months.
The second, is that perhaps other populations of neurons as well as those who regulate the appetite (for example, the crucial ones for memory), they own a privileged way of communication with the intestine and can alter the bacterial composition.
