Reishi (Ganoderma lucidum) has been used in the Far East for approximately 4,000 years. In China it is called Ling Zhi (mushroom of immortality). Historically, it has been used as a longevity herb to treat kidney disorders, liver disorders, bronchitis, asthma, gastric ulcers, fatigue, insomnia, heart disease, cancer, and dizziness, as well as to prevent altitude sickness. There have been many studies on Ganoderma showing it to be antimicrobial (specifically antibacterial against H. pylori and certain species of Klebsiella), and antiviral. Reishi also protects the hippocampus from oxidative impairment and helps benefit factors involved with spatial learning and ones memory, and also protects against severe damage of hippocampal neurons.