Gut cells talk to the brain in milliseconds

Researchers at Duke University, working in mice, found a different wiring entirely: specialized gut lining cells, which the team named neuropod cells, form a direct synaptic connection with the vagus nerve, the same kind of fast junction neurons use to talk to each other.

When nutrients touch the gut lining, a neuropod cell releases glutamate, the same signaling molecule neurons use, directly onto the vagus nerve ending beside it, and the signal reaches the brainstem in a matter of milliseconds, not the seconds or minutes hormones take traveling through blood.

The discovery gave the gut-brain connection a speed it was not thought to have, fast enough that the brain may register what reaches the gut within moments, rather than after digestion has run its course. The work was done in mice, and whether human neuropod cells behave identically has become one of the most active follow-up questions in the field.

A synapse, running from gut to brain.