A gut microbial factor modulates locomotor behaviour in Drosophila

Area of Science:

• Neuroscience
• Microbiology
• Animal Behavior

Background:

• Research on animal behavior often overlooks peripheral influences, despite evidence of gut-brain communication impacting various functions.
• The role of the gut microbiome in regulating host locomotion and its underlying mechanisms remains largely unexplored.

Purpose of the Study:

• To investigate the influence of the gut microbiome on host locomotion in Drosophila melanogaster.
• To identify the molecular and cellular mechanisms by which the gut microbiome modulates motor behavior.

Main Methods:

• Utilized germ-free and antibiotic-treated Drosophila melanogaster models to assess locomotor behavior.
• Investigated the effects of mono-colonization with specific bacteria, including Lactobacillus brevis.
• Examined the role of the bacterial enzyme xylose isomerase and its impact on sugar metabolism.
• Assessed the involvement of octopaminergic neurons and octopamine in mediating these effects.

Main Results:

• Germ-free or antibiotic-treated flies exhibited hyperactive locomotor behavior (increased walking speed and daily activity).
• Mono-colonization with Lactobacillus brevis rescued the hyperactive phenotype.
• The bacterial enzyme xylose isomerase mimicked the locomotor effects of microbial colonization by modulating sugar metabolism.
• Octopaminergic neuron activation or octopamine administration counteracted the effects of xylose isomerase on locomotion.

Conclusions:

• The gut microbiome plays a significant, previously unrecognized role in modulating host locomotion.
• The bacterial enzyme xylose isomerase influences Drosophila locomotion via sugar metabolism.
• Octopaminergic neurons act as crucial mediators, linking peripheral microbial signals to the regulation of motor behavior.