Digestive physiological outcomes related to polydextrose and soluble maize fibre consumption by healthy adult men

Br J Nutr. 2011 Dec;106(12):1864-71. doi: 10.1017/S0007114511002388. Epub 2011 May 31.


The objective of the present study was to evaluate digestive physiological outcomes elicited by functional fibres fed to healthy adult men. A total of twenty-one healthy adult men were utilised in a cross-over design. Each subject received polydextrose (PDX) or soluble maize fibre (SCF) (21 g/d) or no supplemental fibre (no fibre control; NFC) in a snack bar. Periods were 21 d and faeces were collected during the last 5 d of each period. Food intake, including fibre intake, did not differ among treatments. Flatulence (P = 0·001) and distention (P = 0·07) were greatest when subjects consumed PDX or SCF. Reflux was greater (P = 0·04) when subjects consumed SCF compared with NFC. All tolerance scores were low ( < 2·5), indicating only slight discomfort. Faecal ammonia, 4-methylphenol, indole and branched-chain fatty acid concentrations were decreased (P < 0·01) when subjects consumed the functional fibre sources compared with NFC. Faecal acetate, propionate and butyrate concentrations were lower (P < 0·05) when subjects consumed PDX compared with SCF and NFC. Faecal pH was lower (P = 0·01) when subjects consumed SCF compared with NFC, while PDX was intermediate. Faecal wet weight was greatest (P = 0·03) when subjects consumed SCF compared with NFC. Faecal dry weight tended to be greater (P = 0·07) when subjects consumed PDX compared with NFC. The functional fibres led to 1·4 and 0·9 g (PDX and SCF, respectively) increases in faecal dry mass per g supplemental fibre intake. Bifidobacterium spp. concentrations were greater (P < 0·05) when subjects consumed SCF compared with NFC. These functional fibres appear to be beneficial to gut health while leading to minimal gastrointestinal upset.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Cross-Over Studies
  • DNA, Bacterial / genetics
  • DNA, Bacterial / isolation & purification
  • Dietary Fiber / administration & dosage*
  • Dietary Fiber / adverse effects
  • Digestive System Physiological Phenomena*
  • Feces / chemistry
  • Feces / microbiology
  • Fermentation
  • Flatulence / etiology
  • Gastroesophageal Reflux / etiology
  • Glucans / administration & dosage*
  • Glucans / adverse effects
  • Humans
  • Male
  • Metagenome
  • Prebiotics
  • Solubility
  • Young Adult
  • Zea mays


  • DNA, Bacterial
  • Dietary Fiber
  • Glucans
  • Prebiotics
  • polydextrose