Kratom , a tropical tree leaf increasingly being used worldwide as a painkiller and substitute to opioids, may be coming under greater scrutiny in the West, but in Tuana Tuha, an inland village in eastern Borneo in Indonesia, it is considered a godsend and a livelihood. Kratom, or Mitragyna speciosa, is native to Indonesia, Thailand, Malaysia and Papua New Guinea. Its leaves contain mind-altering compounds which affect the same brain receptors as morphine, making kratom a popular herbal…