[Perspective] Fighting the enemy within

The dynamic microbiota that populate all human body surfaces affect health and disease in complex and often subtle ways. At the same time, human gastrointestinal and respiratory tract microbiota are the reservoirs for most of the human pathogens that cause invasive bacterial infections. Antibiotic resistance in such pathogens has dramatically increased in recent years, resulting in infections that are much more difficult to treat (1, 2). To counter this rise, research and development efforts mus