Expression of heat shock protein 27 in gut tissue of growing pigs fed diets without and with inclusion of chicory fiber.

The physiological expression of cytoprotective heat shock protein 27 (Hsp27) in the gut was investigated in eighteen 7-wk-old pigs fed one of 3 fiber-rich diets for 18 d. The diets were a cereal-based control diet and a cereal-based diet with inclusion of either 80 g/kg chicory forage (CF80) or chicory root (CR80). Immunohistochemical staining showed that Hsp27 was expressed in all the samples from ileum and colon. The expression was most intensive in the apical intestinal epitheliums in close contact with luminal contents and lighter in crypt cells. The ileal Peyer's patches showed a strong expression of Hsp27, which was highly correlated with Hsp27 expression in the ileal epithelial cells (P = 0.003). The frequency of ileal Hsp27 expression with the most intensive staining was distributed higher in pigs fed chicory forage diet (CF80, 25%) followed by chicory root diet (CR80, 16.7%) and the control (11.1%). In proximal colon, the frequency of expression showed a similar pattern for the different diets. The intestinal microbiota profile was characterized with the intention to find correlations to heat shock protein (Hsp) expression in pig gastrointestinal (GI) tract and showed that the distal ileum and proximal colon encompass its own unique microbial profile. However, no significant relationship was found between gut microbiota diversity and Hsp27 expression. These indicate that Hsp27 expression in the porcine gut could be associated with specific dietary fiber components but not the overall microbiota diversity.