Methods for detecting risk of having a bloodstream infection and compositions for reducing the risk [patent]

Provided herein is a method for determining the relative abundance of total bacterial in a sample. Optionally, the method also includes determining whether the subject has a risk of bloodstream infection after chemotherapy, such as a chemotherapy used to prepare a subject for a hematopoietic stem cell transplantation procedure. The method includes determining the relative abundances of bacteria that are described herein as correlating with developing a bloodstream infection after chemotherapy, and determining the relative abundances of bacteria that are described herein as correlating with not developing a bloodstream infection after chemotherapy. Also provided is a composition including a mixture of isolated bacteria and a pharmaceutically acceptable carrier, where the bacteria correlate with not developing a bloodstream infection after chemotherapy. Further provided is a method for preventing a bloodstream infection in a subject by administering to a subject a composition that includes at least one type of bacteria that correlates with not developing a bloodstream infection after chemotherapy.