Prebiotics Impact Fecal Microbiota And Gut Physiology In Diet-Induced Obese Mice

Obesity is associated with compromised intestinal barrier function and shifts in microbiota that may contribute to inflammation. Previous research suggests benefits of supplemental fiber, but the impacts of fermentable vs. non‐fermentable fibers are not well understood. OBJECTIVE To determine the impact of cellulose vs. fructan (short‐chain fructooligosaccharides [scFOS] or inulin) supplementation on fecal microbiota and gut physiology in obese mice. METHODS 18‐wk old C57BL/6J mice (n=6/group) were fed high‐fat diets (45% kcal fat) containing 5% cellulose, 10% cellulose, 10% scFOS or 10% inulin for 4‐wk. Cecum and distal colon were collected to assess barrier function, histomorphology and gene expression. Fecal DNA was extracted, followed by 16S rRNA amplicon Illumina MiSeq sequencing and analysis with QIIME 1.8.0. RESULTS Both fructans increased ( p <0.05) intestinal transmural resistance and crypt depth but reduced ( p <0.05) mRNA abundance of ZO‐1 and occludin. Principal coordinates analysis (PCoA) of weighted and unweighted UniFrac distances of fecal microbiota revealed a sharp separation ( p <0.05) between fructan and cellulose groups. Alpha diversity measures revealed lower ( p <0.05) species richness with fructan supplementation. Fructans reduced ( p <0.05) the relative abundance of Firmicutes and increased ( p <0.05) Actinobacteria and Verrucomicrobia ( Akkermansia ). CONCLUSION Fructan supplementation may modulate gut microbiota and physiological responses via multiple mechanisms.