title: Improved Starch Digestion of Sucrase-deficient Shrews Treated With Oral Glucoamylase Enzyme Supplements.
abstract: Although named because of its sucrose hydrolytic activity, this mucosal enzyme plays a leading role in starch digestion because of its maltase and glucoamylase activities. Sucrase-deficient mutant shrews, Suncus murinus, were used as a model to investigate starch digestion in patients with congenital sucrase-isomaltase deficiency.Starch digestion is much more complex than sucrose digestion. Six enzyme activities, 2 α-amylases (Amy), and 4 mucosal α-glucosidases (maltases), including maltase-glucoamylase (Mgam) and sucrase-isomaltase (Si) subunit activities, are needed to digest starch to absorbable free glucose. Amy breaks down insoluble starch to soluble dextrins; mucosal Mgam and Si can either directly digest starch to glucose or convert the post-α-amylolytic dextrins to glucose. Starch digestion is reduced because of sucrase deficiency and oral glucoamylase enzyme supplement can correct the starch maldigestion. The aim of the present study was to measure glucogenesis in suc/suc shrews after feeding of starch and improvement of glucogenesis by oral glucoamylase supplements.
  
  
  
  Sucrase mutant (suc/suc) and heterozygous (+/suc) shrews were fed with C-enriched starch diets. Glucogenesis derived from starch was measured as blood C-glucose enrichment and oral recombinant C-terminal Mgam glucoamylase (M20) was supplemented to improve starch digestion.
  
  
  
  After feedings, suc/suc and +/suc shrews had different starch digestions as shown by blood glucose enrichment and the suc/suc had lower total glucose concentrations. Oral supplements of glucoamylase increased suc/suc total blood glucose and quantitative starch digestion to glucose.
  
  
  
  Sucrase deficiency, in this model of congenital sucrase-isomaltase deficiency, reduces blood glucose response to starch feeding. Supplementing the diet with oral recombinant glucoamylase significantly improved starch digestion in the sucrase-deficient shrew.
authors.affiliation: *USDA/ARS Children's Nutrition Research Center at Baylor College of Medicine and Texas Children's Hospital, Houston, TX †CIEP-Facultad De Ciencias Quimicas, Universidad Autonoma De San Luis Potosi', San Luis Potosi', Mexico ‡Whistler Center for Carbohydrate Research, Department of Food Science, Purdue University, West Lafayette, IN §Bi-State School of Food Science, University of Idaho, Moscow, ID ||Washington State University, Pullman, WA ¶Department of Zoology, Okayama University of Science, Okayama, Japan .
authors.forename: Buford L
authors.initials: BL
authors.lastname: Nichols
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Avery
authors.forename: Roberto
authors.initials: R
authors.lastname: Quezada-Calvillo
authors.forename: Shadi B
authors.initials: SB
authors.lastname: Kilani
authors.forename: Amy Hui-Mei
authors.initials: AH
authors.lastname: Lin
authors.forename: Douglas G
authors.initials: DG
authors.lastname: Burrin
authors.forename: Benjamin E
authors.initials: BE
authors.lastname: Hodges
authors.forename: Shaji K
authors.initials: SK
authors.lastname: Chacko
authors.forename: Antone R
authors.initials: AR
authors.lastname: Opekun
authors.forename: Marwa El
authors.initials: ME
authors.lastname: Hindawy
authors.forename: Bruce R
authors.initials: BR
authors.lastname: Hamaker
authors.forename: Sen-Ichi
authors.initials: SI
authors.lastname: Oda
mesh_terms: D000284:Administration, Oral; D000818:Animals; D030801:Animals, Genetically Modified; D015415:Biomarkers / Q000378:metabolism; D001786:Blood Glucose / Q000378:metabolism; D002239:Carbohydrate Metabolism, Inborn Errors / Q000188:drug therapy* / Q000378:metabolism; D019587:Dietary Supplements; D004063:Digestion / Q000502:physiology*; D005765:Gastrointestinal Agents / Q000627:therapeutic use*; D005087:Glucan 1,4-alpha-Glucosidase / Q000627:therapeutic use*; D008297:Male; D011897:Random Allocation; D012788:Shrews; D013213:Starch / Q000378:metabolism*; D013393:Sucrase / Q000172:deficiency*; D013394:Sucrase-Isomaltase Complex / Q000172:deficiency* / Q000378:metabolism; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D005765:Gastrointestinal Agents; D013213:Starch; D013394:Sucrase-Isomaltase Complex; D005087:Glucan 1,4-alpha-Glucosidase; D013393:Sucrase