I heard of this when i was a kid. Made me wonder if Transformers have metal poop.

https://www.guinnessworldrecords.com/world-records/67621-strangest-diet

During his lifetime, Michel Lotito (France) (b. 15 June 1950) of Grenoble, France, known as Monsieur Mangetout, ate metal and glass throughout his lifetime, beginning in 1959. Gastroenterologists X-rayed his stomach and described his ability to consume 900 g (2 lb) of metal per day as unique.

His diet since 1966 included 18 bicycles, 15 supermarket trolleys, seven TV sets, six chandeliers, two beds, a pair of skis, a low-calorie Cessna light aircraft and a computer. He is said to have provided the only example in history of a coffin (handles and all) ending up inside a man.

He first became aware of his ability when a glass from which he was drinking, broke and he began chewing the fragments. By October 1997, he had eaten nearly 9 tons of metal. He said that bananas and hard-boiled eggs made him sick.

Mr Lotito died of natural causes on June 25, 2007.