Supplemental Dietary Inulin of Variable Chain Lengths Alters Intestinal Bacterial Populations in Young Pigs

Previously we showed that supplementation of diets with short-chain inulin (P95) long-chain inulin (HP) and a 50 50 mixture of both (Synergy 1) improved body iron status and altered expression of the genes involved in iron homeostasis and inflammation in young pigs However the effects of these 3 types of inulin on intestinal bacteria remain unknown Applying terminal restriction fragment length polymorphism analysis we determined the abundances of lumina) and adherent bacterial populations from 6 segments of the small and large intestines of pigs (n = 4 for each group) fed an iron-deficient basal diet (BD) or the BD supplemented with 4% of P95 Synergy 1 or HP for 5 wk Compared with BD all 3 types of inulin enhanced (P < 0 05) the abundance of beneficial bifidobacteria and lactobacilli in the microbiota adherent to intestinal mucus of various gut segments of pigs These changes were seen as proximal as in the Jejunum with P95 but did not appear until the distal ileum or cecum with HP Similar effects of inulin on bacterial populations in the lumen contents were found Meanwhile all 3 types of inulin suppressed the less desirable bacteria Clostridium spp and members of the Enterobacteriaceae in the lumen and mucosa of various gut segments Our findings suggest that the ability of dietary inulin to alter intestinal bacterial populations may partially account for its iron bioavailability-promoting effect and possibly other health benefits J Nutr 140 2158-2161 2010