Probiotics such as bifidobacteria are typically used in cases when a disease occurs or might occur due to a kill-off of normal bacteria. For example, treatment with antibiotics can destroy disease-causing bacteria, but also normal bacteria in the GI (gastrointestinal) and urinary tracts.
The 3-place Hiller Model 360, military H-23 Raven, was based on the U.S. Navy UH-12, which was first flown in 1948. The H-23 Raven performed as a utility, observation, and MedEvac helicopter during the Korean war.
After the Korean War, the 2nd Aviation Company, of the 2nd Infantry Division, which had been the first helicopter unit in Korea, returned to Fort Lewis with observation/ spotter aircraft L-19 Bird Dogs, and L-20 Beavers, as well as H-23 Raven helicopters.