The article, “A MAP for Crohn’s Disease: Old Theory Gains Momentum” (August 2017, page 1) was well written, thoughtful and insightful. It is important because it revisits a controversy that has long been either decried or ignored.
In 1913, Dalziel1 considered the possibility that the causative organism responsible for the disease he was describing was identical to the organism that was responsible for Johne’s disease in cattle.2 That organism is now referred to as