Shaping the gut microbiota of tumour-induced mice with an innovative mixture of dietary fibres designed for food for oncological medical purpose

1. Five different dietary fibres were selected as an innovative dietary fibre mixture for oncological medical purposes on the basis of their lactogenic and bifidogenic effects determined in vitro 2. The administration of the innovative dietary fibre mixture led to an enrichment of favourable species of the gut microbiota with health-promoting benefits and to a depletion of unfavourable gut bacteria in tumour-induced mice 3. The prebiotic effect of the formulated dietary fibre mixture was observed in the enrichment of Bifidobacterium pseudolongum , the strongest predictor species for the prebiotic effect in the gut oncomicrobiomes Food for Special Medical Purposes (FSMP) is a class of therapeutic products specifically formulated for the dietary management of disorders, diseases or conditions in patients. The consumption of dietary fibres, which can be used as components of FSMP, may have a strong influence on the composition of the gut microbiota. Therefore, the objective of this paper was to assess innovative mixture of dietary fibres in FSMP to modulate the imbalanced gut microbiome of the tumour-induced melanoma mouse model. Five different dietary fibres (fructooligosaccharides, long-chain inulin, corn dextrin, gum arabic and citrus fibres) were selected as an innovative dietary fibre mixture for oncological medical purposes based on their lactogenic and bifidogenic effects determined by in vitro experiments. Based on metagenomic analyses of the gut oncomicrobiome of experimental oncological mice, a prebiotic effect was displayed in vivo after administration of the formulated dietary fibre mixture, in particular with regard to an enrichment of Bifidobacterium pseudolongum , the strongest predictor species for the prebiotic effect in the post-fibre gut oncomicrobiomes. An enrichment of favourable gut microbiota species with health-promoting benefits and a depletion of unfavourable gut bacteria were also observed during the application of chemotherapy in tumour-induced mice, with an additional enrichment of favourable gut microbiota species. This suggests that the selected dietary fibres can be used to improve the overall balance of the gut microbiome as an additional intervention in cancer therapy.