Specialized nutrition improves muscle function and physical activity without affecting chemotherapy efficacy in C26 tumour‐bearing mice

Abstract Background Skeletal muscle wasting and fatigue are commonly observed in cancer patients receiving chemotherapy and associated with reduced treatment outcome and quality of life. Nutritional support may mitigate these side effects, but potential interference with chemotherapy efficacy could be of concern. Here, we investigated the effects of an ω‐3 polyunsaturated fatty acid (eicosapentaenoic acid and docosahexaenoic acid), leucine‐enriched, high‐protein (100% whey), additional vitamin D, and prebiotic fibres ‘specific nutritional composition’ (SNC) and chemotherapy on state‐of‐the‐art tumour organoids and muscle cells and studied muscle function, physical activity, systemic inflammation, and chemotherapy efficacy in a mouse model of aggressive colorectal cancer (CRC). Methods Tumour‐bearing mice received a diet with or without SNC. Chemotherapy treatment consisted of oxaliplatin and 5‐fluorouracil. Tumour formation was monitored by calliper measurements. Physical activity was continuously monitored by infrared imaging. Ex vivo muscle performance was determined by myography, muscle fatty acid composition by gas chromatography, and plasma cytokine levels by Luminex xMAP technology. Patient‐derived CRC organoids and C2C12 myotubes were used to determine whether SNC affects chemotherapy sensitivity in vitro. Results Specific nutritional composition increased muscle contraction capacity of chemotherapy‐treated tumour‐bearing mice (P