Gut regulates brain synaptic assembly through neuroendocrine signaling pathway

The gut-brain axis plays an essential role in regulating neural development in response to environmental stimuli, such as microbes or nutrients. Defects in gut-brain communication can lead to various neurological disorders. However, it remains unknown whether gut plays any intrinsic role in regulating neuronal development. Through a genetic screen in C. elegans , we uncovered that an intrinsic Wnt-endocrine pathway in gut regulates synaptic development and neuronal activity in brain. Specifically, the Wnt signaling upregulates the expression of the neuropeptide NLP-40 in the gut, which then facilitates presynaptic assembly through the neuronal expressed GPCR AEX-2 receptor during development. The NLP-40 acts most likely through modulating neuronal activity and promoting synaptic protein trafficking. Therefore, this study reveals a novel role of gut in synaptic development in the brain.