Poster Presentations

Session Title: The Animal Microbiome
Presentation Date: Monday, August 18, 2008
Poster Board Number: 0361

DIETS HIGH IN RED OR WHITE MEATS RESULT IN SIMILAR FAECAL MICROBIAL PROFILES IN RATS BUT PROFILES ARE ALTERED BY DIETARY HIGH AMYLOSE MAIZE STARCH

M. Conlon, S. Toden, M. Vuaran, A. Bird, C. Christophersen, D. Topping
Food Futures National Research Flagship, CSIRO Human Nutrition, Adelaide, Australia

Background and aims: Human population studies show that dietary red and processed meats, but not white meats, are associated with increased risk of colorectal cancer, and that dietary fibre is protective. We have recently demonstrated that the feeding of cooked red and white meats (at 15, 25 and 35 % of diet) for 4 weeks dose-dependently increase colonic DNA single-strand and double-strand breaks in rats but that red meat causes significantly greater damage. Addition of high amylose maize starch (HAMS; a rich source of resistant starch) to the diet (20 %) increased production of short chain fatty acids in the large bowel and protected against the meat-induced damage. The aim of the present study is to determine whether there were changes in the gut microflora in response to dietary treatments in that study.
Methods: Microbial population profiles of faeces collected at the completion of the study were generated by PCR amplification of bacterial 16S rDNA and subsequent denaturing gradient gel electrophoresis (DGGE). ANOSIM was used to compare the DGGE profiles.
Results: There were no significant differences in the dominant bacterial populations between red and white meat treatments but these profiles were significantly altered by inclusion of HAMS in the diet irrespective of the type of meat present.
Conclusions: These results suggest that significant changes in the populations of gut microflora accompany the addition of HAMS to diets high in red and white meats and suggest bacteria play a role in either inducing or protecting against meat-induced colonic DNA damage.