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dc.contributor.advisorDannhauser, A.
dc.contributor.advisorVeldman, F. J.
dc.contributor.authorVan Onselen, Annette
dc.date.accessioned2017-10-24T06:29:15Z
dc.date.available2017-10-24T06:29:15Z
dc.date.issued2002-12
dc.identifier.urihttp://hdl.handle.net/11660/7339
dc.description.abstractEnglish: Dietary fibre has revealed benefits for health maintenance and disease prevention and as a component of medical nutrition therapy. Dietary fibre forms an important part of the Westemised diet, which is characterised by low-fat, low-carbohydrate and low-fibre intake. A high-fibre diet may favourably influence glycometabolic control. It is believed that short-chain fatty acids (SCF As) may partially be responsible for some of the beneficial effects of dietary fibre on metabolism. These SCFAs namely, acetate, propionate and butyrate arc the major products of colonic fibre fermentation. Some of the SCFAs have been shown to improve blood glucose and insulin levels. However, the effect of a combination of SCFAs on glycometabolic control is still unclear. The main aim of the study was to determine the effect of a combination of SCFAs (acetate: propionate: butyrate in the ratio of 70: 15: 15, respectively) and (acetate & propionate: in the ratio of 50:50, respectively) on glycometabolic control in men. The study was a randomised, placebo-controlled, double-blinded clinical trial. Voluntary subjects were recruited for this study using a very strict set of inclusion criteria. All subjects received a placebo for a period of one week following the collection of baseline blood samples and other information. A second baseline blood sample was collected from each individual at the end of this period to ensure accurate reflection of the variables and a stable baseline. Subjects were randomly assigned to three different intervention groups and consumed the different mixtures of either placebo, acetate-propionatebutyrate or acetate-propionate supplement for a period of four weeks following the second baseline blood collection. Supplementation of eight capsules daily was sustained for four weeks. Metabolic indicators (serum glucose, serum insulin, serum albumin, total protein, total cholesterol (TC), high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, non-esterified fatty acids (NEF A), anthropometric status and blood pressure were measured at baseline two (day 8) and after supplementation (day 36). A wash-out period of one week following the supplementation period measured any changes in the metabolic indicators (day 43). The usual dietary intake of the subjects was obtained using a food frequency questionnaire (FFQ) at baseline one (day 0) and after supplementation (day 36). Anthropometric status included body mass index (BMI) and waist-to-hip ratio (WHR), which were measured by means of standardised methods (on days 1, 8 and 36). The BMI and WHR fell within the normal range, and remained within the normal range during the study. This indicated that the subjects were apparently healthy. The study group was also of homogeneous nature, mainly as a result of the strict inclusion criteria applied at the time of recruitment of the subjects. The fasting serum glucose levels were within the higher normal range (5.1 - 5.7mmollL). No statistically significant changes were observed in any of the glycometabolic parameters following supplementation with the different SCFAs regimens (acetate, propionate and butyrate; acetate and propionate). Total cholesterol (TC) levels of the subject group as a whole fell within the normal range of the population (3.0 - 5.2mmollL). However, the observed levels fell in the higher normal range (4.1 - 4.8mmol/L). The HDL-C levels increased slightly in group three (acetate and propionate) and slightly decreased in group two (acetate, propionate and butyrate), however not significantly. The LDL-C significantly decreased in group two (acetate, propionate and butyrate). The observed decreased in systolic blood pressure were statistically significant after the intervention period in group two (acetate, propionate and butyrate). However, observed changes in LDL-C and systolic blood pressure were of no clinical importance. The FFQ indicated a tendency towards the adoption of an atherogenic Westenised diet. This study could not shown that a combination of short chain fatty acids have a beneficial effect on glycometabolic control. The findings of this study are supported by other studies, which indicate that acetate, propionate and butyrate do not improve glucose metabolism in healthy subjects. In contrast, other studies indicated a decrease in fasting serum glucose concentration from propionate (Todesco et aI., 1991) and acetate (Jenkins et aI., 1991) as well as from a combination of acetate, propionate and butyrate (De Wet, 1999). The controversial results regarding the effect of short chain fatty acids on glucose metabolism emphasize the importance of further investigation about the association between physical characteristics and formation of SCFAs, as well as the different combinations of SCFAs over a longer period of time.en_ZA
dc.description.abstractAfrikaans: Dieetvesel toon dat dit voordele inhou vir die instandhouding van gesondheid, voorkomende funksies het teen siektes en ook 'n deel vorm van mediese voedingsterapie. Dieetvesel vorm 'n belangrike deel van die Westerse dieet, wat gekenmerk word deur 'n lae-vet, lae-koolhidraat en lae-vesel inname. 'n Hoë-vesel dieet mag die glukometaboliese kontrole voordelig beïnvloed. Verder mag kort-ketting vetsure (KKV) gedeeltelik verantwoordelik wees vir sommige voordelige effekte van dieetvesel op metabolisme. Hierdie KKV naamlik, asetaat, propionaat en butiraat is die hoofprodukte van fermentasie van vesel in die kolon. Sommige van die KKV het 'n verbetering op bloedglukose en insulienvlakke getoon. Die effek van 'n kombinasie van KKV op glukometaboliese kontrole is nog onduidelik. Die hoofdoelwit van die studie was om te bepaal watter effek 'n kombinasie van KKV (asetaat: propionaat: butiraat in kombinasie van 70:15:15 onderskeidelik) en (asetaat en propionaat: in kombinasie van 50:50 onderskeidelik) op glukometaboliese kontrole in mans het. Die studie was 'n ewekansige plasebo-gekontroleerde dubbelblinde kliniese proef. Vrywillige proefpersone is geselekteer vir hierdie studie volgens baie streng insluitingskriteria. Alle proefpersone het 'n plasebo vir 'n periode van een week ontvang nadat 'n basislyn vir bloedwaardes en ander informasie ontvang is. 'n Tweede basislyn van bloedwaardes is van elke individu aan die einde van hierdie periode geneem om 'n akkurate refleksie van die veranderlikes en 'n betroubare basislyn te verky. Proefpersone is ewekansig in drie verskillende intervensiegroepe verdeel en het verskillende kombinasies ontvang: of 'n plasebo, asetaat, propionaat en butiraat of asetaat-propionaat supplement vir 'n periode van vier weke gevolg deur 'n tweede basislyn van bloedwaardes. Supplementasie van agt kapsules daagliks het vir vier weke plaasgevind. Metaboliese parameters (serum glukose, serum insulien, serum albumien, totale proteine, totale cholesterol (TC), hoë-digtheid lipoproteine (HDL-C), lae-digtheid lipoproteine (LDL-C), nie-veresterde vetsure), antropometriese status en bloeddruk is gemeet op basislyn twee (dag 8) en na supplementasie (dag 36). 'n Uitwasperiode van een week na die supplementasie periode is gedoen om enige veranderinge in die metaboliese parameters te meet (dag 43). Die gebruiklike dieetinname van die proefpersone is verkry deur gebruik te maak van 'n voedselfrekwensievraelys op basislyn een (dag 0) en na supplementasie (dag 36). Antropometriese status het liggaamsmassa-indeks (LMI) en middel-tot-heup verhouding (MHV) ingesluit en is gemeet deur middel van gestandaardiseerde metodes (dag 1, 8 en 36). Die BMI en MHV het in die normale grense geval en so gebly deur die studie. Dit het dus getoon dat die proefpersone oënskynlik gesond was. Die studiegroep was ook homogeen van aard hoofsaaklik as gevolg van die streng insluitingskriteria gedurende die seleksieperiode. Die vastende serumglukose vlakke was binne die hoë normale vlakke (5.1 - 5.7mmol/L). Geen statisties betekenisvolle veranderinge is waargeneem in enige van die glukometaboliese parameters na supplementasie met die KKV (asetaat, propionaat en butiraat ; asetaat en propionaat). Totale cholesterol (TC) vlakke van die groep as 'n geheel het egter binne die normale vlakke van die populasie geval (3.0 - 5.2mmol/L). Die waargenome vlakke het in die hoog normale vlak geval (4.1 - 4.8mmollL). Die HDL-C vlakke het gestyg in groep drie (asetaat en propionaat) en gedaal in groep twee (asetaat,propionaat en butiraat). Die LDL-C vlakke het betekenisvol gedaal in groep twe (asetaat, propionaat en butiraat). Die waargeneemde daling in sistoliese bloeddruk was statisties betekenisvol groep twee (asetaat, propionaat en butiraat). Alhoewel, die veranderinge in LDL-C en sistoliese bloeddruk was nie van kliniese waarde. Die voedselfrekwensievraelys het 'n neiging tot die aankweek van westerse eetpatrone aangetoon. Hierdie studie kon egter nie toon dat 'n kombinasie van KKV a voordelige effek op glukometabolisme het nie. Die bevindinge van hierdie studie word ondersteun deur ander studies wat ook aangedui het dat asetaat, propionaat en butiraat nie glukosemetabolisme in gesonde persone verbeter nie. In teenstelling hiermee het ander studies getoon dat 'n verlaging in vastende serumglukose konsentrasies verkry is na propionaatsupplementasie (Todesco et al., 1991) en asetaatsupplementasie (Jenkins et al., 1991), asook 'n kombinasie van asetaat, propionaat en butiraat (De Wet, 1999). Die teenstrydige resultate van KKV met betrekking tot KKV op glukose metabolisme beklemtoon die belangrikheid van verdere navorsing om die verband tussen fisiese eienskappe en die vorming van KKV, asook die verskillende kombinasies van KKV oor 'n langer periode aan te toon.af
dc.description.sponsorshipNestléen_ZA
dc.language.isoenen_ZA
dc.publisherUniversity of the Free Stateen_ZA
dc.subjectWesternised dieten_ZA
dc.subjectDietary fibreen_ZA
dc.subjectSCFAsen_ZA
dc.subjectSerum glucoseen_ZA
dc.subjectSerum insulinen_ZA
dc.subjectFatty acids in human nutritionen_ZA
dc.subjectDiet therapy -- Nutritionen_ZA
dc.subjectMetabolism -- Regulationen_ZA
dc.subjectDissertation (M.Sc. (Dietetics))--University of the Free State, 2002en_ZA
dc.titleThe effect of a combination of short-chain fatty acids on glycometabolic control in menen_ZA
dc.typeDissertationen_ZA
dc.rights.holderUniversity of the Free Stateen_ZA


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