Let’s not ignore the literal gag. The phrase "ass to mouth" has long been a taboo in adult cinema. Six weaponized that taboo. The film forces the audience to ask: Would you rather be the front, the middle, or the back? The answer reveals a lot about your own psychology. The middle person has the worst fate—consuming waste without the satisfaction of eating, effectively a living filter.
Tom Six famously consulted with real surgeons during the writing process. He claimed that while the idea is horrific, the surgery is technically plausible . The stomach acid of the middle person would likely digest the fecal matter, raising severe toxicity issues in reality, but Six argued that with heavy antibiotics and a controlled diet, the centipede could survive for a few weeks. This pseudo-scientific grounding makes the film significantly more terrifying than a ghost story. the+human+centipede