Retention times, regression coefficients, detection limits and concentration ranges of selected VOC marker substances from breath (a) and feces (b).

R2—coefficient of determination;LOD—limit of detection;LOQ—limit of quantification * potential marker substances from a former in vitro study [9] † values lower than LOD Retention times, regression coefficients, detection limits and concentration ranges of selected VOC marker substances from breath (a) and feces (b).