Effect of anthocyanins on the in vitro fermentation of high-amylose starch

Resistant starch provides beneficial metabolites through gut microbiota fermentation, and the gut microbiota is modulated by the gut redox status. However, the impact of redox status on high-amylose maize starch (HAMS) fermentation metabolism remains uncertain. Anthocyanins (AC) are dietary antioxidants that modulate the redox status. The effect of antioxidant AC on the fermentation metabolism of HAMS was examined using an in vitro fermentation system. AC lowers the system redox potential. The antioxidant AC and fermentation substrate HAMS (HAMS-AC) synergistically increased gas production and short-chain fatty acids and reduced the pH compared to the individual components. AC promotes HAMS fermentation metabolism to produce butyric acid. HAMS-AC also influences gut microbiota composition and metabolic functions. It facilitated beneficial bacteria proliferation, including Collinsella, Faecalibacterium, Agathobacter, Ruminococcus, and Megasphaera, and suppressed harmful bacteria proliferation, including Desulfovibrio, Barnesiella, Alistipes, Parabacteroides, Dorea, Colidextribacter, and Bilophila. HAMS-AC facilitates amino acid and protein synthesis and metabolism, sugar, nucleotide, energy metabolism, and transport. Overall, the antioxidant AC, by lowering the redox potential of the fermentation system, affects the gut microbiota structure and metabolic function and contributes to HAMS metabolism to produce butyric acid. This provides a novel approach for the modulation of intestinal homeostasis and organismal health.