The Kahn-ut-tu were the female members of the Hill People of planet Neural who are trained in shamanism. They were skilled in the plant biology of the planet and knew which roots and herbs would cure certain ailments. These medicinal plants were then combined with shamanistic rituals during the healing process. Most notable of these was the mako root ceremony used to extract Mugato venom from an infected individual.
Kahn-ut-tu women had a very high status in their tribes and were highly sought after as mates. There may be an unseen force (biological or otherwise) that made them particularly attractive. According to regional legend no man could refuse a Kahn-ut-tu once he had been through a medicinal ritual with one. (TOS: "A Private Little War")