The bile sequestrant cholestyramine resin reduces the fitness advantage conferred by very long O-antigen chains in the mouse colitis model.

<p>Mice (129/SvJ) receiving chow containing cholestyramine resin or control chow were pre-treated with streptomycin and infected with an equal mixture of the <i>S.</i> Typhimurium wild type and a <i>fepE</i> mutant. (A) Competitive indices recovered from feces over time. (B) Competitive indices recovered from colon contents. (C) Determination of concentrations of total bile acids in colon contents. (A–C) Bars represent geometric means ± standard error. *, <i>P</i><0.05; **, <i>P</i><0.01. (D) Combined histopathology score of pathological changes observed in sections from the cecum. Lines represent averages. Each circle or diamond represents the combined histopathology score from an individual animal. (E) Representative images of histopathological changes.