[ad_1]
Researchers at Weill Cornell Medicine found that specific bacteria take up residence in the gut soon after birth and produce the neurotransmitter serotonin, which educates the gut’s immune cells. It helps prevent allergic reactions to both food and germs during early development.
The preclinical study, published March 15 in Science Immunology, showed that abundant bacteria in the gut of newborns produce serotonin, which promotes the development of immune cells called T-regulatory cells, or Tregs. These cells suppress inappropriate immune responses to help prevent autoimmune diseases and dangerous allergic reactions to harmless foods or beneficial gut microbes.
“The gut is now known as the second human brain because it produces over 90 percent of the neurotransmitters in the human body. While neurotransmitters such as serotonin are known for their role in brain health, receptors for neurotransmitters are located throughout the human body. ,” explained the study’s senior author, Dr. Melody Zeng, assistant professor of immunology in the Gail & Ira Drukier Institute for Children’s Research and the department of pediatrics at Weill Cornell Medicine.
Gut bacteria provide a helping hand in infants
The researchers observed that the newborn rat intestine had much higher levels of neurotransmitters, including serotonin, compared to the adult intestine. “Until now, almost all studies of gut neurotransmitters were conducted in adult animals or human subjects, where a specific gut cell type called enterochromaffin cells produce the neurotransmitter,” Dr. Zeng said. “However, we found that this is not the case in the newborn’s gut, where most of the serotonin is made by bacteria that are more abundant in the newborn’s gut.”
It was also confirmed in infants through the Human Infant Stool Biobank, which the Zeng lab established in collaboration with the neonatal intensive care unit at NewYork-Presbyterian Alexandra Cohen Hospital for Women and Newborns. These samples were obtained with parental consent and were de-identified.
The study results suggest that before the newborn’s gut is mature enough to make its own neurotransmitters, unique gut bacteria can supply neurotransmitters that are essential for critical biological functions during early development.
“We found that gut bacteria in young mice not only produce serotonin directly, but also reduce an enzyme called monoamine oxidase, which normally breaks down serotonin, thus keeping gut serotonin levels high, ” said Dr. Katherine Sanidad, lead author of the study and postdoctoral associate in pediatrics. At Weill Cornell Medicine.
Higher serotonin levels alter the balance of immune cells by increasing the number of Tregs, which helps prevent the immune system from overreacting and attacking gut bacteria or food antigens. “The newborn’s gut needs these serotonin-producing bacteria to keep the immune system in check,” Dr. Sanidad said.
Healthy immune system helps in later life
Dr. Zeng said this work highlights the importance of having the right types of beneficial bacteria soon after birth. Infants in developed countries have better access to antibiotics, less exposure to various germs in their cleaner environments and potentially unhealthy diets that can significantly impact the abundance of serotonin-producing bacteria in their intestines .
As a result, these babies may have low Tregs and develop an immune response to their gut bacteria, or to food allergies. This may be one reason why food allergies have become increasingly common in children, especially in developed countries. “If properly educated, the immune system in infants will recognize that things like peanuts and eggs are OK, and it doesn’t need to attack them,” she said. It may also have an impact on the development of autoimmune diseases – when the immune system attacks the body’s own healthy cells – later in life.
The team now plans to look at bacteria in human infant stool samples to measure the production of serotonin, other neurotransmitters and molecules that could be used to train the immune system to prevent immune-related diseases like allergies, infections and cancer in the future. Can help.
“It is essential to understand how the immune system is trained during early life, but this has not been studied in newborns and children. Further study of these developmental periods will allow us to better understand how food allergies and inflammatory diseases such as inflammatory bowel disease occur.” Mitigation approaches may be found to reduce the risk of disease later in life,” Dr. Sanidad said.
[ad_2]
