Carnegie Mellon University

Germs: The Good, The Bad, and the Ugly

Course Number: 03120-A1

Bacteria are a scourge to humankind, causing life-threating infections like tuberculosis, meningitis, and pneumonia to the less severe ear infections and strep throats that plague many childhoods. On the other hand, the healthy human microbiota is a community of microorganisms dominated by trillions of bacteria that reside everywhere from our skin to nasal passages and gut. This "virtual organ" is estimated to weigh as much as the human brain and contributes to essential bodily functions like food metabolism and defense against infection, while also impacting memory, anxiety, and depression. Changes in the gut microbiota are also associated with diseases including autism, obesity, allergies, and inflammatory bowel disease. Why the incidence of these chronic diseases is increasing is unclear, but it may be the result of excessive antibiotic use, dietary changes that harm our gut microbes, or both. This century will be marked by both the challenge of antibiotic resistant infectious "bad" bacteria, and the possibilities to harness "good" bacteria to promote human health. In this course, we explore how bacteria make you healthy and what we can do to nurture our microbiota, and how bacteria make you sick and what we can do to stop them.

Academic Year: 2019-2020
Units: 6