The Hollow Instinct

Rethinking Gut Bacteria as Distributed Sensory Organs

We’ve long thought of the gut microbiome as a helpful collection of passengers, digesting fiber, producing vitamins, maybe tweaking our mood. But what if that’s too modest? What if we’re not just hosting them, but using them? What if the gut microbiota are more than a metabolic afterthought, what if they are, functionally, a distributed sensory organ, tuned to chemical worlds our brain cannot directly touch?