In total, 28 multiparous sows (n = 7) and their litters were used to determine the effects of levan-type fructan supplementation on growth performance, nutrient digestibility, blood profiles, and fecal noxious gas emissions. The dietary treatments included (1) CON, basal diet; (2) FC1, CON + 0.1% fructan; (3) FC2, CON + 0.2% fructan; and (4) FC3, CON + 0.3% fructan. No significant differences were observed (P > 0.05) in body weight (BW), average daily feed intake, or back fat loss in lactating sows among treatments. However, blood lymphocyte concentrates were higher (P < 0.05) in sows fed levan-containing diets than in those fed the CON diet. Weaning BW and overall average daily gain (ADG) of piglets in the FC3 treatment were higher (P < 0.05) than piglets in the CON treatment. Blood lymphocytes and nutrient digestibility of sows, as well as the weaning BW and the ADG of piglets were increased linearly (P < 0.05) as the concentration of levan increased in the diet. The diarrhea score of piglets and the fecal gas emissions of sows decreased linearly (P < 0.05) as dietary levan increased. In conclusion, levan supplementation did not affect feed intake or decrease back fat loss of lactating sows, but it improved nutrient digestibility and immune ability, decreased fecal noxious gas emissions of lactating sows, and it improved growth performance and reduced diarrhea in piglets.