Modulation of the human gut microbiota by corn arabinoxylans: insights from in vitro batch culture fermentation

Arabinoxylans (AX) are dietary fibers with strong prebiotic potential to modulate gut microbiota. Six samples (S1–S5 corn AX; S6 inulin as control) were assessed in a 24-h in vitro fermentation model, evaluating microbial composition and short-chain fatty acid (SCFA) production. Distinct, structure-dependent effects were observed. High-molecular-weight AX (S1, S2) selectively enriched Faecalibacterium and sustained acetate and butyrate production throughout fermentation. Medium molecular weight AX (S3) favored Blautia and Oscillospira , with moderate SCFA accumulation. Low molecular weight AX (S4, S5) promoted Blautia , Collinsella , and Faecalibacterium , supporting gradual and sustained SCFA release. In contrast, inulin (S6) stimulated Akkermansia and Collinsella , inducing a rapid early increase in acetate and lactate followed by a decline. Overall, AX molecular weight and structure critically shape microbial responses and metabolic outputs, with high-molecular-weight AX enabling prolonged butyrogenic activity, while inulin drives fast, short-lived fermentation.