Enzymatically Modified Starch Ameliorates Postprandial Serum Triglycerides and Lipid Metabolome in Growing Pigs

<div><p>Developing host digestion-resistant starches to promote human health is of great research interest. Chemically modified starches (CMS) are widely used in processed foods and although the modification of the starch molecule allows specific reduction in digestibility, the metabolic effects of CMS have been less well described. This short-term study evaluated the impact of enzymatically modified starch (EMS) on fasting and postprandial profiles of blood glucose, insulin and lipids, and serum metabolome in growing pigs. Eight jugular-vein catheterized pigs (initial body weight, 37.4 kg; 4 months of age) were fed 2 diets containing 72% purified starch (EMS or waxy corn starch (control)) in a cross-over design for 7 days. On day 8, an 8-hour meal tolerance test (MTT) was performed with serial blood samplings. Besides biochemical analysis, serum was analysed for 201 metabolites through targeted mass spectrometry-based metabolomic approaches. Pigs fed the EMS diet showed increased (<i>P</i><0.05) immediate serum insulin and plasma glucose response compared to pigs fed the control diet; however, area-under-the-curves for insulin and glucose were not different among diets. Results from MTT indicated reduced postprandial serum triglycerides with EMS versus control diet (<i>P</i><0.05). Likewise, serum metabolome profiling identified characteristic changes in glycerophospholipid, lysophospholipids, sphingomyelins and amino acid metabolome profiles with EMS diet compared to control diet. Results showed rapid adaptations of blood metabolites to dietary starch shifts within 7 days. In conclusion, EMS ingestion showed potential to attenuate postprandial raise in serum lipids and suggested constant alteration in the synthesis or breakdown of sphingolipids and phospholipids which might be a health benefit of EMS consumption. Because serum insulin was not lowered, more research is warranted to reveal possible underlying mechanisms behind the observed changes in the profile of serum lipid metabolome in response to EMS consumption.</p></div

Area-under-the-curve 0–480 min values during the meal tolerance test in pigs fed the enzymatically modified starch (EMS) diet or control diet.

<p>^aValues are least squares means ± SEM; control diet, n = 7; EMS diet, n = 6.</p><p>^bNEFA, non-esterified fatty acids.</p><p>Area-under-the-curve 0–480 min values during the meal tolerance test in pigs fed the enzymatically modified starch (EMS) diet or control diet.</p

Serum concentrations of triglycerides (A), cholesterol (B), and non-esterified fatty acids (NEFA) (C) during the meal tolerance test in pigs fed the enzymatically modified starch (EMS) diet or control diet.

<p>Results are presented as least-squares means ± SEM (control diet, n = 7; EMS diet, n = 6). EMS diet versus control diet, *<i>P</i><0.10, **<i>P</i><0.05.</p

Serum concentrations of insulin (A), glucose (B), and lactate (C) during the meal tolerance test in pigs fed the enzymatically modified starch (EMS) diet or control diet.

<p>Results are presented as least-squares means ± SEM (control diet, n = 7; EMS diet, n = 6). EMS diet versus control diet, *<i>P</i><0.10, **<i>P</i><0.05, ***<i>P</i><0.001.</p

Serum amino acids and biogenic amines (μmol/l) of pigs fed the enzymatically modified starch (EMS) diet or control diet in the fasting state and at 60 min postprandially.

<p>^aValues are least squares means ± SEM; control diet, n = 7; EMS diet, n = 6.</p><p>^bADMA, asymmetric dimethylarginine; α-AAA, α-amino adipate; DOPA, dihydroxyphenylalanine; Met-SO, methionine-sulfoxide; SDMA, symmetric dimethylarginine; TDMA, total dimethylarginine.</p><p>^cMean values within a row with different superscript letters were significantly different (<i>P</i><0.05) per sampling time (fasting state or 60 min postprandially).</p><p>^dMean values within a row with different superscript capital letters tended to be different (<i>P</i><0.1) per sampling time (fasting state or 60 min postprandially).</p><p>Serum amino acids and biogenic amines (μmol/l) of pigs fed the enzymatically modified starch (EMS) diet or control diet in the fasting state and at 60 min postprandially.</p

Ingredients and analyzed chemical composition of the experimental diets.

<p>^aAgenanova (AGRANA Stärke, Gmünd, Austria)</p><p>^bFibreCell (agromed Austria GmbH, Kremsmünster, Austria)</p><p>^cProvided per kilogram of complete diet (GARANT GmbH, Pöchlarn, Austria): 16,000 IU of vitamin A, 2,000 IU of vitamin D₃, 125 mg of vitamin E, 2.0 mg of vitamin B₁, 6.0 mg of vitamin B₂, 3.0 mg of vitamin B₆, 0.03 mg of vitamin B₁₂, 3.0 mg of vitamin K₃, 30 mg of niacin, 15.0 mg of pantothenic acid, 900 mg of choline chloride, 0.15 mg of biotin, 1.5 mg of folic acid, 200 mg of vitamin C; 4.6 g of Ca, 2.3 g as digestible P, 2.4 g as Na, 2.0 g of Cl, 3.2 g K, 1.0 g Mg; 50 mg of Mn (as MnO); 100 mg of Zn (as ZnSO₄); 120 mg of Fe (as FeSO₄), 15.6 mg of Cu (as CuSO₄), 0.5 mg of Se (as Na₂SeO₃), 1.9 mg of I (as Ca(IO₃)₂), 3 g TiO₂.</p><p>^dTotal starch was determined using the Total Starch Assay Kit (K-TSTA; Megazyme International Ireland Ltd., Bray, Ireland).</p><p>^eResistant starch was determined using the Resistant Starch Assay Kit (K-STAR; Megazyme International Ireland Ltd., Bray, Ireland).</p><p>Ingredients and analyzed chemical composition of the experimental diets.</p

Selected serum metabolite concentrations (μmol/l) of pigs fed the enzymatically modified starch (EMS) diet or control diet in the fasting state and at 60 min postprandially.

<p>^aValues are least squares means ± SEM; control diet, n = 7; EMS diet, n = 6.</p><p>^bC0, free carnitine; C2, acetylcarnitine; C14:1, tetradecenoylcarnitine; C16, hexadecanoylcarnitine; lysoPC a, lysophophatidylcholine with acyl residue C; SM C, sphingomyelin with C; SM(OH) C; PC aa C, phosphatidylcholine with diacyl residue sum C; PC ae C, phosphatidylcholine with acyl-alkyl residue sum C.</p><p>^cMean values within a row with different superscript letters were significantly different (<i>P</i><0.05) per sampling time (fasting state or 60 min postprandially).</p><p>^dMean values within a row with different superscript capital letters tended to be different (<i>P</i><0.1) per sampling time (fasting state or 60 min postprandially).</p><p>Selected serum metabolite concentrations (μmol/l) of pigs fed the enzymatically modified starch (EMS) diet or control diet in the fasting state and at 60 min postprandially.</p