Importance of Microbiomes in gut: help for babies (Introduction)

by David Turell , Saturday, March 16, 2024, 19:04 (42 days ago) @ David Turell
edited by David Turell, Saturday, March 16, 2024, 19:09

How it begins immunity:

https://www.sciencedaily.com/releases/2024/03/240315161015.htm

"The preclinical study, published in Science Immunology on Mar. 15, showed that bacteria abundant in the guts 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 food items or beneficial gut microbes.

"'The gut is now known as the second human brain as it makes over 90 percent of the neurotransmitters in the human body. While neurotransmitters such as serotonin are best known for their roles in brain health, receptors for neurotransmitters are located throughout the human body," explained the study's senior author, Dr. Melody Zeng, an assistant professor of immunology in the Gale and Ira Drukier Institute for Children's Research.

"The researchers observed that the neonatal mouse gut had much higher levels of neurotransmitters, including serotonin, than the adult gut. "So far, almost all studies of gut neurotransmitters were conducted in adult animals or human subjects, where a specific gut cell type called enterochromaffin cells produce neurotransmitters," said Dr. Zeng. "However, we discovered that this isn't the case in the newborn gut where most of the serotonin is made by bacteria that are more abundant in the neonatal gut."

"This was also confirmed in babies through a human infant stool biobank that the Zeng lab has established in collaboration with the Neonatal Intensive Care Unit in the NewYork-Presbyterian Alexandra Cohen Hospital for Women and Newborns. These samples were obtained with parental consent and deidentified.

"The study results suggest that before the neonatal gut is mature enough to make its own neurotransmitters, unique gut bacteria may supply neurotransmitters that are needed for critical biological functions during early development.

"'We found that gut bacteria in young mice not only directly produce serotonin but also decrease an enzyme called monoamine oxidase that normally breaks down serotonin, thus keeping gut serotonin levels high," said the study's lead author Dr. Katherine Sanidad, postdoctoral associate in pediatrics at Weill Cornell Medicine.

"The high serotonin levels shift 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 neonatal gut needs these serotonin-producing bacteria to keep the immune system in check," Dr. Sanidad added.

"Dr. Zeng noted that this work underscores the importance of having the right types of beneficial bacteria soon after birth. Babies in developed countries have better access to antibiotics, less exposure to diverse microbes in their clean environments and potentially unhealthy diets that may significantly impact the abundance of serotonin-producing bacteria in their intestines. (my bold)

"As a result, these babies may have fewer Tregs and develop immune reactions to their own gut bacteria, or allergies to food. This may be one reason food allergies have become increasingly common in children, particularly in developed countries. "If educated properly, the immune system in babies would recognize that things like peanuts and eggs are okay, and it doesn't have to attack them," she said. This may also have an impact on developing autoimmune diseases -- when the immune system attacks the body's own healthy cells -- later in life. (my bold)

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"'It's essential to understand how the immune system is trained during early life, but this is understudied in newborns and children. Further studies of these developmental periods may hopefully lead us to mitigation approaches to reduce the risk of inflammatory diseases like food allergies and inflammatory bowel disease later in life," Dr. Sanidad said."

Comment: being a little dirty all the time is good. That is the message in my bolded material. The more bugs you meet, the more you are ready for. Some of those gut biome bacteria are quite nasty if they leave the gut and enter other parts of the body. So, the good they do is balanced by the risk they present.