title: Dietary supplementation of propionylated starch to domestic cats provides propionic acid as gluconeogenic substrate potentially sparing the amino acid valine.
abstract: In strict carnivorous domestic cats, a metabolic competition arises between the need to use amino acids for gluconeogenesis and for protein synthesis both in health and disease. The present study investigated the amino acid-sparing potential of propionic acid in cats using dietary propionylated starch (HAMSP) supplementation. A total of thirty cats were fed a homemade diet, supplemented with either HAMSP, acetylated starch (HAMSA) or celite (Control) for three adaptation weeks. Propionylated starch was hypothesised to provide propionic acid as an alternative gluconeogenic substrate to amino acids, whereas acetic acid from HAMSA would not provide any gluconeogenic benefit. Post-adaptation, a 5-d total faecal collection was carried out to calculate apparent protein digestibility coefficients. Fresh faecal and blood samples were collected to analyse fermentation endproducts and metabolites. The apparent protein digestibility coefficients did not differ between supplements (P = 0·372) and were not affected by the protein intake level (P = 0·808). Faecal propionic acid concentrations were higher in HAMSP than in HAMSA (P = 0·018) and Control (P = 0·003) groups, whereas concentrations of ammonia (P = 0·007) were higher in HAMSA than in HAMSP cats. Tendencies for or higher propionylcarnitine concentrations were observed in HAMSP compared with HAMSA (P = 0·090) and Control (P = 0·037) groups, and for tiglyl- + 3-methylcrotonylcarnitine concentrations in HAMSP as compared with Control (P = 0·028) cats. Methylmalonylcarnitine concentrations did not differ between groups (P = 0·740), but were negatively correlated with the protein intake level (r -0·459, P = 0·016). These results suggest that HAMSP cats showed more saccharolytic fermentation patterns than those supplemented with HAMSA, as well as signs of sparing of valine in cats with a sufficient protein intake.
authors.affiliation: Laboratory of Animal Nutrition , Department of Nutrition , Genetics and Ethology , Faculty of Veterinary Medicine , Ghent University , Heidestraat 19 , B-9820 Merelbeke , Belgium.
authors.forename: Kristel
authors.initials: K
authors.lastname: Rochus
authors.affiliation: Laboratory of Animal Nutrition , Department of Nutrition , Genetics and Ethology , Faculty of Veterinary Medicine , Ghent University , Heidestraat 19 , B-9820 Merelbeke , Belgium.
authors.forename: An
authors.initials: A
authors.lastname: Cools
authors.affiliation: Laboratory of Animal Nutrition , Department of Nutrition , Genetics and Ethology , Faculty of Veterinary Medicine , Ghent University , Heidestraat 19 , B-9820 Merelbeke , Belgium.
authors.forename: Geert P J
authors.initials: GP
authors.lastname: Janssens
authors.affiliation: Laboratory of Chemical Analysis , Department of Veterinary Public Health and Food Safety , Faculty of Veterinary Medicine , Ghent University , Salisburylaan 133 , B-9820 Merelbeke , Belgium.
authors.forename: Lynn
authors.initials: L
authors.lastname: Vanhaecke
authors.affiliation: Laboratory of Metabolic Disorders , University Hospital Ghent , De Pintelaan 185 , B-9000 Ghent , Belgium.
authors.forename: Birgitte
authors.initials: B
authors.lastname: Wuyts
authors.affiliation: Preventive Health National Research Flagship and CSIRO Animal , Food and Health Sciences , PO Box 52 , North Ryde , NSW 1670 , Australia.
authors.forename: Trevor
authors.initials: T
authors.lastname: Lockett
authors.affiliation: Preventive Health National Research Flagship and CSIRO Animal , Food and Health Sciences , PO Box 52 , North Ryde , NSW 1670 , Australia.
authors.forename: Julie M
authors.initials: JM
authors.lastname: Clarke
authors.affiliation: Department of Animal Production , Faculty of Bioscience Engineering , Ghent University , Proefhoevestraat 10 , B-9090 Melle , Belgium.
authors.forename: Veerle
authors.initials: V
authors.lastname: Fievez
authors.affiliation: Laboratory of Animal Nutrition , Department of Nutrition , Genetics and Ethology , Faculty of Veterinary Medicine , Ghent University , Heidestraat 19 , B-9820 Merelbeke , Belgium.
authors.forename: Myriam
authors.initials: M
authors.lastname: Hesta
keywords: Acylated starch; DS, degree of substitution; Domestic cats; Fermentation; Gluconeogenesis; HAMSA, acetylated high-amylose maize starch; HAMSP, propionylated high-amylose maize starch; Propionic acid