Vitamin B₁₂ produced by gut bacteria modulates cholinergic signalling

Area of Science:

• Microbiology
• Neuroscience
• Metabolic Engineering

Background:

• Gut microbiota significantly impact host brain function and behavior.
• The precise molecular mechanisms by which gut bacteria influence the nervous system remain largely undefined.

Purpose of the Study:

• To elucidate how vitamin B12-producing gut bacteria modulate host nervous system function and behavior.
• To investigate the role of the methionine/S-adenosylmethionine cycle and choline metabolism in gut-brain communication.

Main Methods:

• Utilized the model organism Caenorhabditis elegans to study gut-brain axis interactions.
• Investigated metabolic pathways including the methionine/S-adenosylmethionine cycle and choline-oxidation pathway.
• Analyzed the impact of bacterial vitamin B12 production on cholinergic signaling and host behavior.

Main Results:

• Vitamin B12-producing bacteria were shown to modulate excitatory cholinergic signaling in C. elegans.
• Vitamin B12 was demonstrated to rewire the methionine/S-adenosylmethionine cycle in the intestine.
• Metabolic rewiring by vitamin B12 limits free choline availability, reducing acetylcholine synthesis and cholinergic signaling.

Conclusions:

• Enteric bacteria can establish a gut-brain communication pathway through vitamin B12 production.
• This pathway involves metabolic crosstalk affecting neurotransmitter synthesis and host behavior.
• Findings suggest a potential link between gut microbiota, vitamin B12 metabolism, and neurological health.