Figure 1. A small molecule clears pathogens from the gut.

a, Spaulding et al.² report that adhesion of the bacterium uropathogenic Escherichia coli (UPEC) to epithelial cells that line the colon of its host is mediated by type 1 and F17-like pili (pili are filamentous protein complexes; F17-like pili are not shown). Type 1 pili bind carbohydrates called glycans that are linked to proteins on the host-cell surface and contain the sugar D-mannose (the glycan depicted here is a simplified schematic, and does not represent a real glycan structure). b, A small molecule called M4284 has a higher affinity for UPEC type 1 pili than does D-mannose. Spaulding and colleagues show that M4284 inhibits the binding of UPEC to colonic epithelial cells and so facilitates the clearance of these bacteria from the gut.