Autism-Associated Gut Microbiota-Derived Enterococcus facium Modulates Gut-Brain Axis Function and Behavior in Mice

Area of Science:

• Neuroscience
• Microbiology
• Gastroenterology

Background:

• Autism spectrum disorder (ASD) is a neurodevelopmental condition with unknown pathogenesis.
• Gut microbiota alterations are increasingly linked to ASD.
• The specific role of Enterococcus faecium in ASD development requires investigation.

Purpose of the Study:

• To investigate the impact of Enterococcus faecium from autistic children on mouse models.
• To assess behavioral, physiological, and neurological changes induced by E. faecium exposure.

Main Methods:

• Oral administration of E. faecium to BALB/c mice for 30 days.
• Behavioral tests (open field, sucrose preference, Y-maze, social interaction).
• Analysis of serum 5-HT, colon/brain tissue for inflammation and BBB integrity, and stool DNA sequencing for microbiota analysis.

Main Results:

• E. faecium induced anxiety, depression, memory impairment, and social dysfunction in mice.
• Intestinal damage, increased inflammation, reduced tight junction proteins, and decreased mucin-2 were observed.
• Systemic inflammation (elevated LPS), gut dysbiosis, neural damage, and compromised blood-brain barrier integrity in the brain were noted.

Conclusions:

• Enterococcus faecium from autistic patients can induce significant behavioral and neurological changes in mice.
• These effects are potentially mediated by gut microbiota dysbiosis, intestinal barrier disruption, and neuroinflammation.
• E. faecium may contribute to gut-brain axis dysregulation in autism spectrum disorder.