DIETARY SUPPLEMENTATION WITH BLACK RASPBERRIES FOR PREVENTION OF COLITIS-ASSOCIATED COLORECTAL CANCER IN MICE.

Dietary strategies to reduce colonic inflammation and promote gut homeostasis may markedly reduce the risk of colitis-associated colorectal cancer (CAC). Black raspberries have demonstrated protective effects against colitis and/or colorectal cancer via their antioxidant and anti-inflammatory actions at the colon epithelium. Moreover, consumption of these foods can lead to changes in the composition of the gut microbiome. The overall objective of this study was to determine the impact of dietary supplementation with whole, freeze-dried raspberries on colitis and colon tumorigenesis in mice consuming a Western type diet. C57BL/6J male mice were fed a standard diet (AIN93G), the total Western diet (TWD), TWD + 5% black raspberry powder (BRB) or TWD+ 10% BRB for 16 weeks. All mice were dosed with axozymethane and provided 1% dextran sodium sulfate in drinking water for 10 days to promote colonic inflammation and tumor formation. Endpoints assessed included colon tumor formation, symptoms of colitis, colon length, cecum weight, and body and fat mass gain. Mice fed TWD alone had a markedly higher colitis disease activity index score compared to mice provided the standard AIN93G diet, whereas supplementation with 10% BRB markedly reduced colitis symptoms immediately after DSS treatment and two weeks later during a recovery phase. As colitis is a major contributor to colon tumorigenesis, we expect to observe a similar pattern with respect to colon tumor multiplicity and burden. Also of interest was the apparent significant increase in fat mass in mice fed TWD, which was further enhanced in mice provided 10% BRB. This observation may be explained by the significant increase in food and energy intake by mice supplemented with BRB as compared to TWD-fed mice. Collectively, these data suggest that BRB supplementation may ameliorate gut inflammation, but may also impact body composition in mice