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.
The small number of evacuations and rescues during World War II were enough to make it clear that the helicopter was the future of battlefield MedEvac. The Korean War brought that promise to an operational reality. In Korea, the use of helicopters as ambulances was especially important due to the physical landscape.