This study compared the effects of a resistant starch (RS)-rich, arabinoxylan (AX)-rich, or low-DF Western-style control diet (all high-fat) on large intestinal gene expression, adiposity, and glycemic response parameters in pigs. Animals were slaughtered after 3 weeks of treatment. Plasma butyrate concentration was higher following the high-DF diets, whereas plasma glucose, insulin, and insulin resistance increased after 3 weeks irrespective of diet. The mRNA abundance in the large intestine of genes involved in nutrient transport, immune response, and intestinal permeability was affected by segment (cecum, proximal, mid or distal colon) and some genes also by diet. In contrast, there was no diet-induced effect on adipose mRNA abundance or adipocyte size. Overall, a high level of RS or AX did not demonstrate strong beneficial effects on large intestinal gene expression as indicators of colonic health or glycemic response parameters when included in a high-fat diet for pigs as a model of healthy humans.
Keywords: blood metabolites; colon; dietary fiber; insulin; short-chain fatty acids; transcription.