Soluble Fiber and Insoluble Fiber Regulate Colonic Microbiota and Barrier Function in a Piglet Model

Abstract

The main purpose of the present study was to assess the effect of soluble and insoluble fiber on colonic bacteria and intestinal barrier function in a piglet model. A total of 24 piglets (25 ± 1 d old; 7.50 ± 0.31 kg) were randomly allotted to 4 treatments: basal diet (control, CON), 1% insoluble dietary fiber (IDF) diet, 1% soluble dietary fiber (SDF) diet, and 0.5% insoluble fiber + 0.5% soluble dietary fiber (MDF) diet. The trial lasted 28 days. SDF-fed piglets showed a higher P<0.05 bacterial a-diversity (observed_species, chao1, and ACE) and a higher relative abundance of Proteobacteria and Actinobacteria, Solobacterium, Succinivibrio, Blautia, and Atopobium in colonic digesta than CON, IDF, and MDF groups P<0.05. At the same time, Bacteroidetes, Euryarchaeota, Phascolarctobacterium, Coprococcus_1, and Prevotella_1 were significantly increased in the IDF group when compared with CON, SDF, and MDF groups P<0.05. Furthermore, Bacteroidetes and Enterobacteriaceae, Selenomonas, Phascolarctobacterium, and AlloprevotellaP<0.05 were significantly higher in the MDF group than those in the other three groups P<0.05. SDF diet increased the concentrations of short-chain fatty acid (SCFA) in colonic digesta P<0.05 when compared with the CON group and enhanced weight index of the colon P<0.05 than the CON and IDF groups. Furthermore, compared with the CON group, SDF, IDF, and MDF diets all upregulated the mRNA expressions of claudin-1 (CLDN-1) in colonic mucosa P<0.05, SDF and IDF diets upregulated the mRNA expressions of mucin 2 (MUC2) P<0.05, SDF diet increased mRNA expressions of zonula occludens 1 (ZO-1) and occludin (OCLN), while the IDF group enhanced the secretory immunoglobulin A (sIgA) concentrations P<0.05, respectively. IDF and MDF diets decreased expressions of TNF-αP<0.05. We concluded that the influence of soluble fiber on colonic microbiota was more extensive than that of insoluble fiber. Moreover, soluble fiber could more effectively improve colonic barrier function by upregulating gene expressions of the gut barrier.

Highly Fermentable Fiber Alters Fecal Microbiota and Mitigates Swine Dysentery Induced by Brachyspira hyodysenteriae

“…Association between Prevotella spp. and dietary fiber, particularly insoluble dietary fiber, has been observed previously in piglets supplemented with 1% lignocellulose [ 56 ]. This same study also observed that 1% inulin reduces Prevotellaceae abundance compared with piglets fed either 1% insoluble fiber or a standard corn soy diet [ 56 ].…”

Xylanase modulates the microbiota of ileal mucosa and digesta of pigs fed corn-based arabinoxylans likely through both a stimbiotic and prebiotic mechanism

“…In a healthy state, the pig and gastrointestinal microbiota share a symbiotic relationship that contributes to the nutrition and health of the pig, and in turn, the pig provides substrate for microbiota largely in the form of DF. However, all DF is not created equal and its efficacy to modulate microbial taxa, diversity, and composition is dependent on DF composition, solubility, and concentration [ 33 , 34 ]. In general, soluble DF and non-digestible oligosaccharides are fermented at a faster rate compared to insoluble DF [ 35 , 36 ] and are associated with reducing pathogenetic microbes, increasing microbial diversity, and improving the proliferation of ‘beneficial’ microbes [ 37 , 38 ].…”

Of men in mice: the development and application of a humanized gnotobiotic mouse model for microbiome therapeutics

“…The importance of the type of dietary fiber was recently demonstrated by Deehan et al 51 ; small discrete alterations in the chemical structure of fibers caused distinct enrichments of certain taxa, leading to altered metabolite output. More specifically, soluble fibers increase the alpha diversity and relative abundance of Proteobacteria and Actinobacteria, whereas insoluble fibers increase Bacteroidetes and Euryarchaeota, as well as IgA and tumor necrosis factor-alpha levels 52 . Thus, both human donor and murine recipient diets must be carefully assessed for desirable FMT outcomes.…”