Gene expression levels in the jejunum and the caecum of GF, SPF and C groups. In the jejunum, the gene expression levels of IL-1β and IL-8 (A and B respectively) were higher in C and SPF as compared to GF. In the cæcum, IL-1β and IL-8 were overexpressed in C group as compared to SPF and GF. IL-8 and TLR4 mRNA level were also higher respectively in SPF and C groups compared to GF. (n = 8; mean ± standard deviation;*p < 0.05; **p < 0.01; ***p < 0.001). IL-1β and IL-8 data (A, B, D, E) were analysed using the Kruskal-Wallis test followed by the Mann–Whitney test; TLR4 data (C, F) were analysed using one-way ANOVA followed by the Bonferroni-Dunn test.