The role of digestion as a factor in the colorectal cancer promoting effect of (processed) red meat will be investigated. Gastrointestinal digests will be generated in vitro, and analysed using untargeted mass spectrometry based fingerprinting. In parallel, the digests will undergo geno- and cell toxicity evaluation using DNA adduct profiling, and cell lines in a new continuous long-term exposure approach. A small-scale human intervention with a strictly controlled diet will also be performed.