By acting on the parts of the brain that deal with threat, the composition of infants’ gut microbiota could influence how they respond to fear.
THE ESSENTIAL
- A good balance of the intestinal flora in the baby limits his fear reactions
- It is the link between the microbiota and the part of the brain that manages the reaction to a threat that would be involved.
What if babies’ reaction to fear depended on their gut microbiota? This is the surprising question that researchers have tried to answer. Their work has just been published in the journal type communications and for them, for sure, there is a link! They go even further: according to them, the intestinal microbiota could help to control the healthy neurological development of children.
Work carried out on thirty babies
The intestinal microbiota has many virtues, because it influences a large part of the body, such as the immune system, the brain, the cardiovascular system or the bone system, etc. Inside it lives a whole set of microorganisms – bacteria, viruses, parasites and non-pathogenic fungi – whose diversity is essential for a good balance of the intestinal microbiota. To understand whether this part of the body influences the fear reactions of babies, the scientists carried out their work on thirty infants who were not taking antibiotics and were breastfed. They first had them perform stool analyzes in order to characterize their microbiota and then evaluated their reaction to a situation of fear: each baby was placed in a room where an individual wearing a Halloween mask entered. “We really wanted the experience to be enjoyable for the children and their parents, reassures Rebecca Knickmeyer, author of the study. The parents were there all the time and they could intervene when they wanted.”
The composition of the microbiota influences how we react to fear
The researchers then cross-referenced the babies’ reactions with the characteristics of their gut microbiota. They thus observed that those whose part of the intestine was composed of a small set of bacteria were more frightened than those whose intestinal flora was more balanced. In other words, those who were the most afraid had the same types of microorganisms in their microbiota, and vice versa for those who were not afraid. Scientists therefore felt that the content of the microbial community did indeed influence the level of fear expressed by babies. In addition, the researchers studied the brains of one-year-old children by having them undergo medical imaging examinations. According to them, the content of the microbial community at this age is associated with the size of the amygdala, a part of the brain involved in making quick decisions about potential threats. On the other hand, the researchers did not identify a link between the microbiota and the way the cubs reacted to the presence of a stranger not wearing a mask. “With strangers there is a social element, points out Rebecca Knickmeyer. So children may be socially suspicious, but they don’t see strangers as immediate threats.”. The reaction to a stranger would therefore not solicit the same regions of the brain.
The composition of the microbiota would help better neurological development
“We have a new lever to better monitor the neurological health of children from an early age (…), if they cannot decrease their fear reaction when they are safe, they are more likely to develop, later anxiety and depressionassures Rebecca Knickmeyer. Our long-term goal is to understand how to act (on the intestinal microbiota) to promote development (neurological) healthier“. Conversely, children with no reaction to fear at all could, in adulthood, have insensitive character traits, associated with antisocial behavior. The scientists therefore believe that the study of babies’ gut microbiota could help to better understand and monitor the mental health of these future adults.”This period of early development is a great time to support healthy brain development.concludes Rebecca Knickmeyer. The microbiome is an exciting new target that can potentially be used for this”.
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