This study was conducted to investigate the effects of dietary supplementation with 2 sources of fiber, sugar beet pulp (SBP), and wheat bran (WB), on sow performance, milk quality, and intestinal health in piglets. Forty-five multiparous sows at day 85 of gestation were allocated to the following 3 treatments: 1) a corn-soybean meal basal diet (CON); 2) the CON diet supplemented with 20% SBP in gestation and 10% SBP in lactation (SBP); and 3) the CON diet supplemented with 30% WB in gestation and 15% WB in lactation (WB). The SBP diets increased (P < 0.05) sow ADFI during lactation, litter and piglet weaning weight, piglet ADG, immunoglobulin A (IgA), and interleukin-10 (IL-10) levels in the colostrum and IgA levels in the milk, while the WB diets only increased (P < 0.05) IL-10 levels in the milk when compared with the CON diets. Piglets from SBP-fed sows had greater (P < 0.05) serum growth hormone and insulin-like growth factor-1 levels than those from WB-fed or CON-fed sows, whereas piglets from WB-fed sows had greater (P < 0.05) serum GH levels than those from CON-fed sows. Serum diamine oxidase activity, endotoxin, IL-6, and tumor necrosis factor-α (TNF-α) levels were reduced (P < 0.05) in piglets from SBP-fed or WB-fed sows. Piglets from SBP-fed sows also had greater (P < 0.05) serum IL-10 levels than those from CON-fed sows. The ileal mRNA expression of TNF-α was reduced (P < 0.05) in piglets from SBP-fed or WB-fed sows. Piglets from SBP-fed sows had lower (P < 0.05) IL-6 expression, and greater (P < 0.05) IL-10 expression and secretory immunoglobulin A (SIgA) levels in the ileum than those from WB- or CON-fed sows. Piglets from WB-fed sows had greater (P < 0.05) IL-10 expression and SIgA levels compared with those from CON-fed sows. The ileal mRNA expression of occludin in the ileum was greater (P < 0.05) in piglets from SBP-fed sows than those from CON-fed sows. The ileal mRNA expression of ZO-1 was greater (P < 0.05) in piglets from WB-fed sows than those from CON-fed sows, but lower (P < 0.05) than those from SBP-fed sows. Piglets from SBP-fed sows had greater (P < 0.05) abundance of Christensenellaceae and butyrate levels in the colon, while piglets from WB-fed sows had greater (P < 0.05) abundance of Lactobacillaceae. Collectively, maternal SBP supplementation was more effective than WB in improving milk quality, enhancing growth performance and intestinal barrier function, and ameliorating intestinal inflammation in piglets.