title: Delayed gastric emptying and reduced postprandial small bowel water content of equicaloric whole meal bread versus rice meals in healthy subjects: novel MRI insights.
abstract: OBJECTIVE
  Postprandial bloating is a common symptom in patients with functional gastrointestinal (GI) diseases. Whole meal bread (WMB) often aggravates such symptoms though the mechanisms are unclear. We used magnetic resonance imaging (MRI) to monitor the intragastric fate of a WMB meal (11% bran) compared with a rice pudding (RP) meal.
  
  
  METHODS
  Twelve healthy volunteers completed this randomised crossover study. They fasted overnight and after an initial MRI scan consumed a glass of orange juice with a 2267 kJ WMB or an equicaloric RP meal. Subjects underwent serial MRI scans every 45 min up to 270 min to assess gastric volumes and small bowel water content, and completed a GI symptom questionnaire.
  
  
  RESULTS
  The MRI intragastric appearance of the two meals was markedly different. The WMB meal formed a homogeneous dark bolus with brighter liquid signal surrounding it. The RP meal separated into an upper liquid layer and a lower particulate layer allowing more rapid emptying of the liquid compared with solid phase (sieving). The WMB meal had longer gastric half-emptying times (132±8 min) compared with the RP meal (104±7 min), P<0.008. The WMB meal was associated with markedly reduced MRI-visible small bowel free mobile water content compared with the RP meal, P<0.0001.
  
  
  CONCLUSIONS
  WMB bread forms a homogeneous bolus in the stomach, which inhibits gastric sieving and hence empties slower than the equicaloric rice meal. These properties may explain why wheat causes postprandial bloating and could be exploited to design foods that prolong satiation.
authors.affiliation: University of Nottingham, Nottingham, UK.
authors.forename: L
authors.initials: L
authors.lastname: Marciani
authors.forename: S E
authors.initials: SE
authors.lastname: Pritchard
authors.forename: C
authors.initials: C
authors.lastname: Hellier-Woods
authors.forename: C
authors.initials: C
authors.lastname: Costigan
authors.forename: C L
authors.initials: CL
authors.lastname: Hoad
authors.forename: P A
authors.initials: PA
authors.lastname: Gowland
authors.forename: R C
authors.initials: RC
authors.lastname: Spiller
mesh_terms: D015992:Body Mass Index; D001939:Bread; D018592:Cross-Over Studies; D005260:Female; D005746:Gastric Emptying / Q000502:physiology*; D005753:Gastric Mucosa / Q000378:metabolism; D064368:Healthy Volunteers; D006801:Humans; D007421:Intestine, Small / Q000378:metabolism*; D008279:Magnetic Resonance Imaging; D008297:Male; D062407:Meals; D012275:Oryza; D019518:Postprandial Period / Q000502:physiology*; D012527:Satiation; D011795:Surveys and Questionnaires; D014867:Water / Q000502:physiology*; D055815:Young Adult
chemical_list: D014867:Water