Reduced Dietary Intake of Carbohydrates by Obese Subjects Results in Decreased Concentrations of Butyrate and Butyrate-Producing Bacteria in Feces

Sylvia H. Duncan, Alvaro Belenguer, Grietje Holtrop, Alexandra M. Johnstone, Harry James Flint, Gerald E. Lobley

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553 Citations (Scopus)


Weight loss diets for humans that are based on a high intake of protein but low intake of fermentable carbohydrate may alter microbial activity and bacterial populations in the large intestine and thus impact on gut health. In this study, 19 healthy, obese (body mass index range, 30 to 42) volunteers were given in succession three different diets: maintenance (M) for 3 days (399 g carbohydrate/day) and then high protein/medium (164 g/day) carbohydrate (HPMC) and high protein/low (24 g/day) carbohydrate (HPLC) each for 4 weeks. Stool samples were collected at the end of each dietary regimen. Total fecal short-chain fatty acids were 114 mM, 74 mM, and 56 mM (P < 0.001) for M, HPMC, and HPLC diets, respectively, and there was a disproportionate reduction in fecal butyrate (18 mM, 9 mM, and 4 mM, respectively; P < 0.001) with decreasing carbohydrate. Major groups of fecal bacteria were monitored using nine 16S rRNA-targeted fluorescence in situ hybridization probes, relative to counts obtained with the broad probe Eub338. No significant change was seen in the relative counts of the bacteroides (Bac303) (mean, 29.6%) or the clostridial cluster XIVa (Erec482, 23.3%), cluster IX (Prop853, 9.3%), or cluster IV (Fprau645, 11.6%; Rbro730 plus Rfla729, 9.3%) groups. In contrast, the Roseburia spp. and Eubacterium rectale subgroup of cluster XIVa (11%, 8%, and 3% for M, HPMC, and HPLC, respectively; P < 0.001) and bifidobacteria (4%, 2.1%, and 1.9%, respectively; P = 0.026) decreased as carbohydrate intake decreased. The abundance of butyrate-producing bacteria related to Roseburia spp. and E. rectale correlated well with the decline in fecal butyrate.

Original languageEnglish
Pages (from-to)1073-1078
Number of pages6
JournalApplied and Environmental Microbiology
Issue number4
Early online date22 Dec 2006
Publication statusPublished - Feb 2007


  • in-situ hybridization
  • targeted oligonucleotide PROBES
  • human large-intestine
  • chain fatty-acids
  • human colon
  • human gut
  • plant polysaccharides
  • fecal microbiota
  • crohns-disease
  • dominant group

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