Disruptions of the intestinal microbiota linked to aggression

While antibiotics can fight bacterial diseases, they can also disrupt the “good bacteria” in your gut. And this alteration of the gut microbiota doesn’t just lead to potential digestive problems, according to a Bar-Ilan University study published in the journal Brain, Behavior, and Immunity.

Researchers have discovered a link between disruptions in the gut microbiota and increased aggression.

Altered microbiota leads to increased aggression

After observing a correlation between antibiotic exposure and increased aggression in fruit flies, the scientists decided to assess the potential impact of altered microbiota in humans. To do this, they implanted the microbiota of human infants into mice via fecal transplants. Some came from babies who had taken antibiotics shortly after birth. The others were taken from pups who had never received medication. All treated animals were then put into contact with a foreign conspecific.

The team then examined their behavior, but also biochemical and neurological changes through several tests. For example, they carried out urine tests and measured the level of serotonin or tryptophan in the brain.

Three to five weeks after transplantation, animals with altered microbiota from antibiotics were more aggressive than those treated with healthy stools.

Microbiome: new therapeutic avenues for aggression-related disorders

Another finding of the researchers: significant changes in metabolites and genetic expression linked to aggression were observed in the brains of rodents.

These data reveal the importance of the gut-brain axis and the role of the gut microbiome in modulating aggression. Furthermore, for the researchers, their study highlights its potential pathways of action, offering perspectives for the development of therapeutic strategies for aggression-related disorders.