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 United States lacked a guerrilla warfare capability at the start of the Korean War, and had to put one together, and fast. The result was the 8240th Army Unit, comprised of Rangers and other soldiers with unconventional warfare experience from World War II.