Gut microbial taxa elevated by dietary sugar disrupt memory function.

Area of Science:

• Neuroscience
• Microbiology
• Developmental Biology

Background:

• Emerging evidence links gut microbiota to neurocognitive development.
• Early life excessive sugar consumption is associated with gut dysbiosis and neurocognitive impairments.
• The functional connection between these outcomes remains unclear.

Purpose of the Study:

• To investigate if excessive early life sugar consumption impairs memory function through the gut microbiome.
• To explore the relationship between sugar-induced microbiome alterations and neurocognitive outcomes.

Main Methods:

• Adolescent rats were given access to sugar-sweetened beverages (SSB).
• Adult rats underwent behavioral tests for memory and anxiety.
• Gut bacterial composition, brain transcriptome, and microbial enrichment experiments were performed.

Main Results:

• Chronic SSB consumption impaired adult hippocampal-dependent memory but not anxiety or body weight.
• SSB consumption altered the gut microbiome, increasing Parabacteroides abundance, which correlated with impaired memory.
• Enrichment of Parabacteroides in adolescent rats led to impaired adult memory.

Conclusions:

• Early life sugar consumption negatively impacts memory function via gut microbiota dysbiosis.
• The gut bacterium Parabacteroides plays a role in mediating sugar's detrimental effects on hippocampal memory.
• Findings highlight the gut microbiome as a mediator of unhealthy dietary impacts on neurodevelopment.