Image credit: Arek Socha
Penicillin in early life changes microbiome and gene expression, which allows cells to respond to its changing environment, in key areas of the developing brain, according to new research.
Penicillin and related medicines (like ampicillin and amoxicillin) are the most widely used antibiotics in children worldwide.
In the United States, the average child receives nearly three courses of antibiotics before the age of two. Similar or greater exposure rates occur in many other countries.
“Our previous work has shown that exposing young animals to antibiotics changes their metabolism and immunity,” said Professor Martin Blaser, director of the Center for Advanced Biotechnology and Medicine at Rutgers University.
“The third important development in early life involves the brain.”
“This study is preliminary but shows a correlation between altering the microbiome and changes in the brain that should be further explored.”
In the study, Professor Blaser and his colleagues compared mice that were exposed to low-dose penicillin in utero or immediately after birth to those that were not exposed.
They found that mice given penicillin experienced substantial changes in their intestinal microbiota and had altered gene expression in the frontal cortex and amygdala, two key areas in the brain responsible for the development of memory as well as fear and stress responses.
A growing body of evidence links phenomena in the intestinal tract with signaling to the brain, a field of study known as the gut-brain-axis.
If this pathway is disturbed, it can lead to permanent altering of the brain’s structure and function and possibly lead to neuropsychiatric or neurodegenerative disorders in later childhood or adulthood.
“Early life is a critical period for neurodevelopment,” Professor Blaser noted.
“In recent decades, there has been a rise in the incidence of childhood neurodevelopmental disorders, including autism spectrum disorder, attention deficit/hyperactivity disorder and learning disabilities.”
Angelina Volkova et al. Effects of early-life penicillin exposure on the gut microbiome and frontal cortex and amygdala gene expression. iScience, published online July 15, 2021; doi: 10.1016/j.isci.2021.102797