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.
Most of the Army's major combat equipment -- the M48 tank, the M59 armored personnel carrier, and the M74 and M51 tank recovery vehicles -- had been developed during or before the Korean Campaign and was no longer capable of meeting modern wartime requirements. Many of the Army's small arms were carryovers from World War II.