The impact of NSP differing in viscosity and fermentability on intestinal mineral flux in pigs is largely unknown. Therefore, the effects of 5% low fermentable, low viscous cellulose (CEL), low fermentable, high viscous carboxymethylcellulose (CMC), high fermentable, low viscous oat beta-glucan (LG) and high fermentable, high viscous oat beta-glucan (HG) on Heal and faecal recovery and postileal flux of Ca and Zn were studied in 8 ileal-cannulated barrows (30 kg BW) according to a double 4 x 4 Latin square. Ileal and faecal recovery of Ca and Zn was lowest (P<0.05) for CMC and highest for HG. For all treatments faecal recovery of Zn was 1.5 to 2 times higher (P<0.05) than ileal recoveries, indicating a net secretion into the large intestine. Absorption of Ca and Zn secretion was non-linearly related (P<0.01) to postileal DM digestibility suggesting a relationship between fermentation and mineral flux in the large intestine. In conclusion, colonic fermentation of NSP or other dietary components affects the local mineral flux in pigs, possibly due to microbial requirements for minerals. Viscosity of NSP did not appear to be an important component to explain effects of NSP sources. (C) 2010 Elsevier B.V. All rights reserved.