The Other Factor

People are mostly bacterial cells, and researchers are beginning to understand how those microorganisms can affect health — especially chronic disease, writes The Economist. Washington University in St. Louis' Jeffrey Gordon has shown that overweight people have difference bacterial flora than slim people and that malnourished people have different flora than well-nourished people. The microbiome's reach goes beyond nutrition and weight, The Economist adds, and may contribute to heart disease, diabetes, and autoimmune disorders like multiple sclerosis and asthma.