While gut bacteria have different abilities to utilize dietary fibers, the degree of fiber structural alignment to bacteria species is not well understood. Corn bran arabinoxylan (CAX) was used to investigate how minor polymer fine structural differences at the genotype × environment level influences the human gut microbiota. CAXs were extracted from 4 corn genotypes × 3 growing years and used in in vitro fecal fermentations. CAXs from different genotypes had varied contents of arabinose/xylose ratio (0.46−0.54), galactose (58−101 mg/g), glucuronic acid (18−32 mg/g). There was genotype- but not environment-specific differences in fine structures. After 24 h fermentation, CAX showed different acetate (71−86 mM), propionate (35−44 mM), butyrate (7−10 mM), and total short chain fatty acid (SCFA) (117−137 mM) production. SCFA profiles and gut microbiota both shifted in a genotype-specific way. In conclusion, the study reveals a very high specificity of fiber structure to gut bacteria use and SCFA production.

尽管肠道细菌具有利用膳食纤维的不同能力，但人们对纤维结构与细菌种类的排列程度却知之甚少。玉米糠阿拉伯木聚糖（CAX）用于研究基因型×环境水平的微小聚合物精细结构差异如何影响人类肠道菌群。从4种玉米基因型×3个生长年中提取CAX，并用于体外粪便发酵。来自不同基因型的CAX具有不同含量的阿拉伯糖/木糖比（0.46-0.54），半乳糖（58-101 mg / g），葡萄糖醛酸（18-32 mg / g）。在精细结构上有基因型差异，但没有环境差异。发酵24小时后，CAX显示出不同的乙酸盐（71-86 mM），丙酸盐（35-44 mM），丁酸盐（7-10 mM）和总短链脂肪酸（SCFA）（117-137 mM）产量。SCFA图谱和肠道菌群均以基因型特异性方式移动。总而言之，该研究表明纤维结构对肠道细菌的使用和SCFA的生产具有很高的特异性。