CgA protein expression in human colon epithelial cells. The percentage of CgA positive staining cells was calculated in crypts in the field and mid-sigmoid samples. (A) Graphs showing no relationship between butyrate concentration and CgA expression in the field (contra-lateral) but a moderate, almost significant inverse correlation at the mid-sigmoid (r = -0.370; p = 0.053) (B) Graph showing the data as mean ± SEM when grouped into tertiles according to butyrate concentration. In the contra-lateral samples there were no differences seen, but in the mid-sigmoid a significant difference was seen between the low butyrate and high butyrate groups (p = 0.037). (C) Graph comparing butyrate concentration and the percentage of CgA expression in the contralateral (white bars) and mid-sigmoid (filled bars) samples. No significant differences were seen between the field and mid-sigmoid samples in any groups.