Abstract:

Objective  To study the effect of resistant starch (RS) on intestinal function and aberrant crypt foci (ACF) for colorectal cancer in rats. Methods   A total of 50 male Wistar rats were randomly divided into 5 groups: the negative control group，the positive control group and three different RS added groups (RS concentration was 7.6%, 15.2% and 22.8%). Rats in the positive control group were subcutaneously injected with azoxymethane (AOM) once a week in the second and third weeks. Rats in the negative control group were injected with saline. Animals in different RS added groups were given the same treatment as the positive control group and received the corresponding doses of RS. Rats in the control groups received ordinary feed. Body weights were recorded weekly throughout the study. Fecal pH was measured at the 5th weekend and the gastrointestinal transit time (GTT) measurement was carried out at the 7th weekend. Rats were killed on the 16th week. Colons of rats were removed to determine the ACF index. Results  Compared with the positive control group, the three RS added groups had an obviously reduced number of ACF and GTT(P＜0.01) . The fecal pH was significantly decreased due to the addition of RS to the diet (P＜0.05). Conclusion  RS is beneficial to maintain intestinal health and can reduce the formation of ACF, which might be one of the mechanisms of preventing colorectal cancer.

Key words: Resistant starch; Colorectal neoplasms; Aberrant Crypt Foci; Rats, Wistar