摘要Background:Sows are frequently subjected to various stresses during late gestation and lactation, which trigger inflammatory response and metabolic disorders. Dietary fiber can influence animal health by modulating gut microbiota and their by-products, with the effects depending upon the source of the dietary fiber. This study aimed to evaluate the impacts of different fiber sources on body condition, serum biochemical parameters, inflammatory responses and fecal microbiota in sows from late gestation to lactation. Methods:Forty-five multiparous sows (Yorkshire × Landrace;3–6 parity) were assigned to 1 of 3 dietary treatments from d 85 of gestation to the end of lactation (d 21 post-farrowing):a control diet (CON, a corn-soybean meal diet), a sugar beet pulp diet (SBP, 20％SBP during gestation and 10％SBP during lactation), and a wheat bran diet (WB, 30％WB during gestation and 15％WB during lactation). Results:Compared with CON, supplementation of SBP decreased (P<0.05) lactation BW loss, reduced (P<0.05) serum concentration of total cholesterol, non-esterified fatty acids, interleukin-6 and tumor necrosis factor-α, and increased (P<0.05) fecal water content on d 110 of gestation and d 21 of lactation, while supplementation of WB reduced (P<0.05) serum concentration of total cholesterol on d 110 of gestation, increased (P<0.05) fecal water content and decreased (P<0.05) serum interleukin-6 concentration on d 110 of gestation and d 21 of lactation. In addition, sows fed SBP had lower (P<0.01) abundance of Clostridium_sensu_stricto_1 and Terrisporobacter than those fed CON, but had greater (P<0.05) abundance of Christensenellaceae_R-7_group and Ruminococcaceae_UCG-002 than those fed the other two diets on d 110 of gestation. On d 21 of lactation, supplementation of SBP decreased (P<0.05) the abundance of Firmicutes and Lactobacillus, but enriched (P<0.05) the abundance of Christensenellaceae_R-7_group, Prevotellaceae_NK3B31_group, Ruminococcaceae_UCG-002, Prevotellaceae_UCG_001 and unclassified_f__Lachnospiraceae compared with WB. Compared with CON, sows fed SBP had greater (P<0.05) fecal concentrations of acetate, butyrate and total SCFAs during gestation and lactation, while sows fed WB only had greater (P<0.05) fecal concentration of butyrate during lactation. (Continued from previous page) Conclusions:Supplementation of dietary fiber during late gestation and lactation could improve sow metabolism and gut health, and SBP was more effective than WB.