Malnutrition is linked to lack of microbes.
Environmental Stress => Lack of microbes => Malnutrition => Cellular Stress => Viral infection, Autoimmune disorders, Cancer, TB, Organ failures
Epidemics followed by World War 1 and World War 2 are testimonies.
https://www.sciencedaily.com/releases/2015/02/150212131514.htm
