β-Glucans have been identified as natural biomolecules with immunomodulatory activity. The first objective of the present study was to compare the effects of purified β-glucans derived fromLaminariadigitata,L. hyperboreaandSaccharomyces cerevisiaeon piglet performance, selected bacterial populations and intestinal volatile fatty acid (VFA) production. The second aim was to compare the gene expression profiles of the markers of pro- and anti-inflammation in both unchallenged and lipopolysaccharide (LPS)-challenged ileal and colonic tissues. β-Glucans were included at 250 mg/kg in the diets. The β-glucans derived fromL. hyperborea,L. digitataandS. cerevisiaeall reduced the Enterobacteriaceae population (P < 0·05) without influencing the lactobacilli and bifidobacteria populations (P>0·05) in the ileum and colon. There was a significant interaction between gastrointestinal region and β-glucan source in the expression of cytokine markers, IL-1α (P < 0·001), IL-10 (P < 0·05), TNF-α (P < 0·05) and IL-17A (P < 0·001). β-Glucans did not stimulate any pro- or anti-inflammatory cytokine markers in the ileal epithelial cells. In contrast, the expression of a panel of pro- and anti-inflammatory cytokines (IL-1α,IL-10,TNF-αandIL-17A) was down-regulated in the colon following exposure to β-glucans from all the three sources. However, the data suggest that the soluble β-glucans derived fromL. digitatamay be acting via a different mechanism from the insoluble β-glucans derived fromL. hyperboreaandS. cerevisiae, as the VFA profile was different in theL. digitata-treated animals. There was an increase inIL-8gene expression (P < 0·05) in the gastrointestinal tract from the animals exposed toL. digitatafollowing an LPSex vivochallenge that was not evident in the other two treatment groups. In conclusion, β-glucans from both seaweed and yeast sources reduce Enterobacteriaceae counts and pro-inflammatory markers in the colon, though the mechanisms of action may be different between the soluble and insoluble fibre sources.

The aim of this study was to determine the anti-inflammatory potential of pomegranate peel extracts (PPE) prepared from waste material of pomegranate juice production both in vitro on Caco-2 cells and ex vivo using porcine colonic tissue explants. Caco-2 cells were stimulated in vitro by TNF and colonic tissue explants were stimulated ex vivo with lipopolysaccharide (LPS). Both tissues were co-treated with PPE at 0, 1.0, 2.5, 5.0, 10 and 25 μg/mL. The secretion of CXCL8 in the supernatant of both experiments was determined by enzyme linked immunosorbent assay (ELISA) and the relative expression of inflammatory cytokines were evaluated in the colonic tissue by quantitative polymerase chain reaction (QPCR). The 2.5 to 25 μg/mL of PPE suppressed CXCL8 (p < 0.001) in the Caco-2 cells, whereas CXCL8 production was suppressed by only 5 and 25 μg/mL (p < 0.01) of PPE in the colonic explants. The 5 μg/mL of PPE also suppressed the expression of IL1A (p < 0.05), IL6 (p < 0.01) and CXCL8 (p < 0.05) in LPS challenged colonic tissues compared to controls. In conclusion, the 5 μg/mL of PPE consistently elicits strong anti-inflammatory activity. These results support the potential of bioactive compounds from the waste peel of pomegranate in terms of their anti-inflammatory activity in cells and tissues of the gastrointestinal tract.

In the present study, two experiments were conducted to (1) evaluate the effect of laminarin and/or fucoidan on ileal morphology, nutrient transporter gene expression and coefficient of total tract apparent digestibility (CTTAD) of nutrients and (2) determine whether laminarin inclusion could be used as an alternative to ZnO supplementation in weaned pig diets. Expt 1 was designed as a 2 × 2 factorial arrangement, comprising four dietary treatments (n 7 replicates, weaning age 24 d, live weight 6·9 kg). The dietary treatments were as follows: (1) basal diet; (2) basal diet+300 ppm laminarin; (3) basal diet+240 ppm fucoidan; (4) basal diet+300 ppm laminarin and 240 ppm fucoidan. There was an interaction between laminarin and fucoidan on the CTTAD of gross energy (GE) (P< 0·05) and the expression of sodium–glucose-linked transporter 1 (SGLT1/SLC5A1) and GLUT1/SLC2A1 and GLUT2/SLC2A2 (P< 0·05) in the ileum. The laminarin diet increased the CTTAD of GE and increased the expression of SGLT1, GLUT1 and GLUT2 compared with the basal diet. However, there was no effect of laminarin supplementation on these variables when combined with fucoidan. Expt 2 was designed as a complete randomised design (n 8 replicates/treatment, weaning age 24 d, live weight 7·0 kg), and the treatments were (1) basal diet, (2) basal diet and laminarin (300 ppm), and (3) basal diet and ZnO (3100 ppm, 0–14 d, and 2600 ppm, 15–32 d post-weaning). The laminarin diet increased average daily gain and gain:feed ratio compared with the basal diet during days 0–32 post-weaning (P< 0·01) and had an effect similar to the ZnO diet. These results demonstrate that laminarin provides a dietary means to improve gut health and growth performance post-weaning.

The aim of the present study was to establish the optimum inclusion level of laminarin derived fromLaminaria digitataon selected microbial populations, intestinal fermentation, cytokine and mucin gene expression in the porcine ileum and colon. A total of twenty-one pigs (mean body weight 17·9 kg) were randomly assigned to one of three dietary treatments: T1 – basal (control) diet, T2 and T3 – basal diets supplemented with laminarin included at 300 and 600 parts per million (ppm), respectively. Selected intestinal bacterial populations and volatile fatty acid (VFA) concentrations were measured in the ileum and colon. Relative gene expression levels for specific cytokine and mucin genes were investigated in ileal and colonic tissue in the absence and presence of a lipopolysaccharide (LPS) challenge. There was an up-regulation ofMUC2gene expression at the 300 ppm inclusion level in the ileum. In the colon, there was a significant reduction in the enterobacteriaceae population at the 300 ppm inclusion level (P = 0·0421). Dietary supplementation of 600 ppm laminarin led to a significant increase inMUC2(P = 0·0365) andMUC4(P = 0·0401) expression in the colon, and in the total VFA concentration in the caecum (P = 0·0489). A significant increase was also recorded inIL-6(P = 0·0289) andIL-8gene expression (P = 0·0245) in LPS-challenged colonic tissue at both laminarin inclusion levels. In conclusion, dietary inclusion of 300 ppm laminarin appears to be the optimum dose in the present study due to the reduction in the enterobacteriaceae populations and enhanced IL-6 and IL-8 cytokine expression in response to anex vivoLPS challenge.

A potential control strategy for nematode infection in sheep is the implementation of a breeding programme to select for genes associated with resistance. The Texel breed is more resistant to gastrointestinal nematode infection than the Suffolk breed, based on faecal egg count, and this difference should enable the identification of some of the genes responsible for resistance. The objective of this study was to determine if variation at the ovine MHC-DRB1 locus was associated with variation in faecal egg count in Suffolk and Texel sheep. Ovar-DRB1 alleles and faecal egg count were determined for Texel (n=105) and Suffolk (n=71) lambs. Eight Ovar-DRB1 alleles, including 1 previously unknown allele, were identified in the Texel breed by sequence-base-typing. Seven Ovar-DRB1 alleles were identified in the Suffolk breed. Two Ovar-DRB1 alleles were common to both breeds, but were among the least frequent in the Suffolk population. In the Suffolk breed 1 Ovar-DRB1 allele was associated with a decrease in faecal egg count and 2 alleles with an increase in faecal egg count. This locus accounted for 14% of the natural variation in faecal egg count in Suffolks. There was no evidence for an association between Ovar-DRB1 alleles and faecal egg count in the Texel breed and the Ovar-DRB1 locus accounted for only 3% of the phenotypic variation in faecal egg count. These results suggest that the Ovar-DRB1 gene plays an important role in resistance to nematode infection in the Suffolk breed. The difference in faecal egg counts between these breeds may be attributable in part to the different allele profile at the Ovar-DRB1 locus.