title: Arabinoxylans and inulin differentially modulate the mucosal and luminal gut microbiota and mucin-degradation in humanized rats.
abstract: The endogenous gut microbiota affects the host in many ways. Prebiotics should favour beneficial intestinal microbes and thus improve host health. In this study, we investigated how a novel class of potential prebiotic long-chain arabinoxylans (LC-AX) and the well-established prebiotic inulin (IN) modulate the gut microbiota of humanized rats. Six weeks after axenic rats were inoculated with a human faecal microbiota, their colonic microbiota was similar to this inoculum (∼ 70%), whereas their caecal microbiota was enriched with Verrucomicrobia and Firmicutes concomitant with lower abundance of Bacteroidetes. Moreover, different Bifidobacterium species colonized the lumen (B. adolescentis) and mucus (B. longum and B. bifidum). Both LC-AX and IN increased SCFA levels and induced a shift from acetate towards health-promoting propionate and butyrate respectively. By applying a high-resolution phylogenetic micro-array (HITChip) at the site of fermentation (caecum), IN and LC-AX were shown to stimulate bacterial groups with known butyrate-producers (Roseburia intestinalis, Eubacterium rectale, Anaerostipes caccae) and bifidobacteria (B. longum) respectively. Prebiotic administration also resulted in lower caecal abundances of the mucin-degrading Akkermansia muciniphila and potentially more mucin production by the host. Both factors might explain the increased caecal mucin levels for LC-AX (threefold) and IN (sixfold). These mucins were degraded along the colon, resulting in high faecal abundances of Akkermansia muciniphila for LC-AX and especially IN-treated rats. Finally, the microbial changes caused an adaptation period for the host with less weight gain, after which the host fine-tuned the interaction with this altered microbiota. Our results demonstrate that next to IN, LC-AX are promising prebiotic compounds by stimulating production of health-promoting metabolites by specific microbes in the proximal regions. Further, prebiotic supplementation shifted mucin degradation to distal regions, where mucin-degraders may produce beneficial metabolites (e.g. propionate by Akkermansia muciniphila), so that prebiotics may potentially improve gut health along the entire length of the intestine.
authors: Laboratory of Microbial Ecology and Technology, Ghent University, Coupure Links 653, 9000 Ghent, Belgium.
authors: Pieter
authors: P
authors: Van den Abbeele
authors: Philippe
authors: P
authors: Gérard
authors: Sylvie
authors: S
authors: Rabot
authors: Aurélia
authors: A
authors: Bruneau
authors: Sahar
authors: S
authors: El Aidy
authors: Muriel
authors: M
authors: Derrien
authors: Michiel
authors: M
authors: Kleerebezem
authors: Erwin G
authors: EG
authors: Zoetendal
authors: Hauke
authors: H
authors: Smidt
authors: Willy
authors: W
authors: Verstraete
authors: Tom
authors: T
authors: Van de Wiele
authors: Sam
authors: S
authors: Possemiers
mesh_terms: D000818:Animals; D001419:Bacteria / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D002432:Cecum / Q000382:microbiology*; D003106:Colon / Q000382:microbiology*; D005243:Feces / Q000382:microbiology; D005285:Fermentation; D006801:Humans; D007444:Inulin / Q000494:pharmacology*; D008297:Male; D054892:Metagenome / Q000187:drug effects*; D009077:Mucins / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D010802:Phylogeny; D056692:Prebiotics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D051381:Rats; D011916:Rats, Inbred F344; D014990:Xylans / Q000494:pharmacology*; D055815:Young Adult
chemical_list: D009077:Mucins; D056692:Prebiotics; D012336:RNA, Ribosomal, 16S; D014990:Xylans; D007444:Inulin; C085118:arabinoxylan