Living cells engineered to detect and report conditions like this are called what?

Biosensors is the name given to living cells engineered to detect and report conditions like disease signs inside the body, since scientists build genetic circuits into organisms like gut bacteria that switch on, often producing a visible glow or color change, only when the bacteria encounter specific molecules associated with a health problem such as inflammation or bleeding.

Antibiotics are drugs that kill or inhibit bacteria to treat infections, a therapeutic tool rather than a diagnostic sensor built from living cells. Painkillers are medications that reduce pain sensation, again a treatment rather than a detection technology.

In animal trials, ingestible bacterial biosensors have successfully detected gut bleeding and signaled the finding electronically, hinting at a future where swallowable living sensors could monitor internal health conditions in real time.