The human gastrointestinal tract is colonized by a large diversity of health-associated bacteria, which comprise the gut microbiota. Sequence-based, culture-independent approaches have revolutionized our view of this microbial ecosystem. However, many of its members are nonculturable under laboratory conditions. Some bacteria can enter the viable but nonculturable (VBNC) state. VBNC bacteria do not form colonies in standard medium, although they exhibit – albeit very low – metabolic activity, and can even produce toxic proteins. The VBNC state can be regarded as strategy that permits bacteria to cope with stressful environments. In this commentary, we discuss factors that promote the resuscitation of VBNC bacteria, and highlight the role of extracellular pyruvate, based on our own work on the significance of pyruvate sensing and transport for the resuscitation of Escherichia coli cells from the VBNC state.
Gastrointestinal tract; Gastrointestinal Bacteria; Nonculturable; VBNC Bacteria; Escherichia coli