Supplemental Dietary Inulin of Variable Chain Lengths Alters Intestinal Bacterial Populations in Young Pigs1–3

Abstract

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 luminal 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.

Inclusion of Chicory (Cichorium intybus L.) in Pigs' Diets Affects the Intestinal Microenvironment and the Gut Microbiota

“…This in vitro effect of inulin could not be verified in the present in vivo study. One reason could be that in vivo, the microbiota of the large intestine is affected not only directly by inulin itself but also indirectly by the metabolites produced and by cross-feeding (24,26). Nevertheless, our results indicated that butyrate-producing bacteria were responsive to alternative dietary substrates.…”

“…Chicory root, which has a high content of inulin-type fructan and oligofructose, is a prototype prebiotic for monogastrics (32). Previous studies have reported that inulin-type fructan and oligofructose can promote the growth of beneficial microbes, such as bifidobacteria and lactic acid bacteria (LAB), along the gastrointestinal (GI) tract (26,33). In contrast, little is known about the effect of chicory forage inclusion upon the composition of porcine gut microbiota.…”

Impact of chicory inclusion in a cereal-based diet on digestibility, organ size and faecal microbiota in growing pigs

“…The microbial ecosystem in the gastrointestinal (GI) tract is characterized by a high population density, wide diversity and complexity of hostmicrobe and microbe-microbe interactions (Zoetendal et al, 2004). However, the knowledge about the gut microbial diversity is still far from complete and the use of molecular techniques has revealed that many of the pig gut microbial communities have not previously been cultured (Leser et al, 2002;Castillo et al, 2007;Patterson et al, 2010).…”

Use of pigs as a potential model for research into dietary modulation of the human gut microbiota

“…In this context, the beneficial effects of inulin on the gut microbiota in human subjects have been described, particularly by enhancing colonic bifidobacteria numbers, although results may vary probably due to variations in chain length and dosage of the type of inulin used (10) . For example, in a study of Patterson et al (126) with pigs, a short-chain inulin product was already partly fermented in the jejunum and ileum. In contrast, long-chain inulin was not degraded until reaching the distal ileum or the caecum (126) .…”

“…For example, in a study of Patterson et al (126) with pigs, a short-chain inulin product was already partly fermented in the jejunum and ileum. In contrast, long-chain inulin was not degraded until reaching the distal ileum or the caecum (126) . Increased numbers of bifidobacteria have been detected upon dietary supplementation with prebiotic fructooligosaccharides (FOS) in studies with human subjects (10,127) , while infant formula supplemented with a mixture of galacto-oligosaccharides and FOS resulted in higher faecal counts of bifidobacteria and lactobacilli compared with infants fed unsupplemented formula (78) .…”