Anti-metastatic potential of anthocyanins and their metabolites (metabotypes) on cancer cell lines with different phenotypes - role of intestinal fermentation and metabolization.

Interventions: Group 1: Arm 1 - 0.33 L Anthocyanin-rich blueberry / grape juice daily for 28 days. This is followed by a wash-out period of 10 days and a run-in phase of 7 days.
Group 2: Arm 1 - 0.33 L Anthocyanin-reduced blueberry / grape juice daily for 28 days. This is followed by a wash-out period of 10 days and a run-in phase of 7 days.
Primary outcome(s): Inhibition of tumor cell migration in vitro after application of plasma-isolated anthocyanins and metabolites. The endpoint is recorded after 28 days compared to day 1.
Study Design: Allocation: Randomized controlled study; Masking: Blinded (masking used); Control: placebo; Assignment: crossover; Study design purpose: basic science