A structure defined pectin SA02B from Semiaquilegia adoxoides is metabolized by human gut microbes

Polysaccharide is one of the major factors for shaping the gut microbiota. However, bioactivity of polysaccharide isolated from Semiaquilegia adoxoides on human gut microbiota remains unclear. Thus, we hypothesize gut microbes may act on it. Herein, pectin SA02B from the roots of Semiaquilegia adoxoides with molecular weight 69.26 kDa was elucidated. The backbone of SA02B was composed of alternate 1, 2-linked α-Rhap and 1, 4-linked α-GalpA, with branches of terminal (T) -, 1, 4-, 1, 3- and 1, 3, 6-linked β-Galp, T-, 1, 5- and 1, 3, 5-linked α-Araf and T-, 1, 4-linked-β-Xylp substituted at C-4 of 1, 2, 4-linked α-Rhap. Bioactivity screening showed SA02B promoted the growth of Bacteroides spp. which deconstructed it into monosaccharide. Simultaneously, we observed competition might exist between Bacteroides spp. and probiotics. Besides, we found that both Bacteroides spp. and probiotics could generate SCFAs grown on SA02B. Our findings highlight SA02B may deserve as a prebiotic to be explored to benefit the health gut microbiota.