Postprandial PYY increase by resistant starch supplementation is independent of net portal appearance of short-chain fatty acids in pigs

PLoS One. 2017 Oct 5;12(10):e0185927. doi: 10.1371/journal.pone.0185927. eCollection 2017.

Abstract

Increased dietary fiber (DF) fermentation and short-chain fatty acid (SCFA) production may stimulate peptide tyrosine-tyrosine (PYY) secretion. In this study, the effects of hindgut SCFA production on postprandial PYY plasma levels were assessed using different experimental diets in a porto-arterial catheterized pig model. The pigs were fed experimental diets varying in source and levels of DF for one week in 3×3 Latin square designs. The DF sources were whole-wheat grain, wheat aleurone, rye aleurone-rich flour, rye flakes, and resistant starch. Postprandial blood samples were collected from the catheters and analyzed for PYY levels and net portal appearance (NPA) of PYY was correlated to NPA of SCFA. No significant effects of diets on NPA of PYY were observed (P > 0.05), however, resistant starch supplementation increased postprandial NPA of PYY levels by 37 to 54% compared with rye-based and Western-style control diets (P = 0.19). This increase was caused by higher mesenteric artery and portal vein PYY plasma levels (P < 0.001) and was independent of SCFA absorption (P > 0.05). The PYY levels were higher in response to the second daily meal compared with the first daily meal (P < 0.001), but similar among diets (P > 0.10). In conclusion, the increased postprandial PYY responses in pigs fed with different levels and sources of DF are not caused by an increased SCFA absorption and suggest that other mechanisms such as neural reflexes and possibly an increased flow of digesta in the small intestine may be involved. The content of DF and SCFA production did not affect PYY levels.

MeSH terms

  • Animals
  • Dietary Supplements*
  • Fatty Acids, Volatile / blood*
  • Peptides / metabolism*
  • Postprandial Period*
  • Starch / administration & dosage*
  • Swine
  • Tyrosine / metabolism*

Substances

  • Fatty Acids, Volatile
  • Peptides
  • Tyrosine
  • Starch

Grants and funding

The present research projects were financially supported by The Danish Strategic Research Council, project “Concepts for enhanced butyrate production to improve colonic health and insulin sensitivity – ButCoIns” (Project No. 10-093526), and by the European Commission in the Communities Sixth Framework Programme, Project HEALTHGRAIN (FOOD-CT-2005-514008) to KEBK. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.