Interactive and individual effects of dietary non-digestible carbohydrates and oils on DNA damage, SCFA and bacteria in the large bowel of rats

摘要

Dietary non-digestible carbohydrates (NDC) play an important role in large-bowel health and one form of NDC, resistant starch (RS), can promotenlow levels of DNA damage and other markers of colonic health. The objective of the present study was to determine whether the ability of dietarynRS or other NDC to influence colonic health, particularly DNA damage, is dependent on the type of dietary oil. We compared the effects of dietsncontaining 10% of NDC from cellulose, wheat bran, high-amylose maize starch (HAS, a rich source of RS type 2) or a retrograded HAS (RHAS, anrich source of RS type 3) on DNA damage, SCFA production and bacterial changes in the large bowel of rats. Each carbohydrate source wasncombined with 10% fish oil (FO) or Sunolae oil (SO; rich in oleic acid). There was a significant interaction between NDC and oil treatmentsnon single-strand DNA breaks in colonocytes isolated from the colon. The damage in rats consuming RHAS was greater for FO consumptionnthan for SO consumption. There was a significant interaction between NDC and oils on caecum weights and treatment effects of NDC andnoils were observed for the weights and lengths of other gut tissues. Significant differences were found in colonic SCFA pools and caecal numbersnof lactobacilli, bifidobacteria, Escherichia coli and Bacteroides fragilis with the various NDC and oil treatments. The present results demonstratenthat the effects of NDC and oils, particularly on colonic DNA damage, can depend on how they are combined within the diet.