Infancy Antibiotic Use and Increased Aggressive Behavior: A Study on the Association

Scientists have found a link between antibiotic use in infancy and increased aggressive behavior. Research shows that early disruption of the gut microbiome, particularly through antibiotic use, leads to heightened aggression in mice.

A study led by Professor Omry Koren and Dr. Atara Uzzan-Yuzari of Bar-Ilan University revealed this phenomenon. They transplanted the microbiomes of infants treated with antibiotics into mice and found a significant increase in aggression in these mice.

Using the "resident-intruder" paradigm, the study observed that antibiotics reduce gut bacterial diversity, directly linking this to increased aggression. Metabolites and gene expression related to aggression in the mice's brains also changed.

The study employed "humanized" mice, which are mice implanted with human gut bacteria, enhancing the relevance of the results to human behavior. It also explored the biochemical mechanisms behind the behavioral changes, measuring levels of neurotransmitters in the mice's brains.

The results indicate that the gut-brain axis plays a crucial role in the development of aggressive behavior, especially during critical developmental periods like infancy. This provides new insights into how early interventions can influence long-term behavioral outcomes.

Key Term Explanations:

• Gut Microbiome: The community of microorganisms living in the gut, which significantly impacts health.
• Humanized Mice: Mice implanted with human gut bacteria, used to study human health and behavior.
• Gut-Brain Axis: The interaction between the gut and the brain, influencing behavior and mood.