Neuronal aryl hydrocarbon receptor shapes gut microbiome via redox signalling in C. elegans

The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor best known for its role in mediating responses to environmental toxins and in intestinal immunity. It has previously been shown to influence gut microbial composition, but the mechanisms by which it does so — and whether the nervous system plays a direct role in this regulation — have remained unclear.

A preprint posted to bioRxiv uses Caenorhabditis elegans to show that AHR-1 expressed in neurons, rather than in the gut itself, orchestrates selective gut microbiome assembly. The authors identify a neuroendocrine pathway involving redox tone as the signalling mechanism: neuronal AHR-1 modulates the oxidative environment of the intestinal lumen, which in turn selectively favours or disfavours the growth of particular bacterial species.

The findings add to a growing literature on neuroendocrine control of host-microbe interactions and suggest that gut microbial composition is not determined solely by local intestinal factors but can be influenced by distant neurological signals. C. elegans is a tractable model organism for dissecting such pathways at genetic resolution.

The study is a preprint and has not yet been peer-reviewed. Further work will be needed to determine how conserved this neuroendocrine–microbiome axis is in other organisms.