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Diets enriched in oat bran or wheat bran temporally and differentially alter the composition of the fecal community of rats.
- Source :
-
The Journal of nutrition [J Nutr] 2009 Nov; Vol. 139 (11), pp. 2024-31. Date of Electronic Publication: 2009 Sep 23. - Publication Year :
- 2009
-
Abstract
- A clear understanding of how diet alters gastrointestinal communities is important given the suggested link between gut community composition and a wide variety of disease pathologies. To characterize this link for commonly consumed dietary fiber sources, we investigated the change in the fecal community of rats fed diets containing 5% nonnutritive fiber (control), 3% (wt:wt) oat bran plus 2% nonnutritive fiber (OB), or 5% (w/w) wheat bran (WB) over a 28-d feeding trial using both molecular- and cultivation-based methodologies. Pooled fecal samples from 8 rats fed the same diet were analyzed at 4 time points. On d 28, bran-fed rats had approximately twice the total cultivable bacteria than rats fed the control diet. Over the course of feeding, the cultivable community was initially dominated by bacteroides, then by bifidobacteria, lactobacilli, enterococci, and various enterics. In contrast, molecular analysis revealed the appearance of new operational taxonomic units (phylotypes) that were both temporally and inequitably distributed throughout the fecal community. The majority of change occurred in 2 major lineages within the Firmicutes: the Clostridium coccoides group and the Clostridium leptum subgroup. The time course of change depended on the source of bran, with the majority of new phylotypes appearing by d 14 (OB) or d 28 (WB), although adaptation of the fecal community was slow and continued over the entire feeding trial. Bacterial community richness was higher in bran-fed rats than in those fed the control diet. Change within the C. coccoides and C. leptum lineages likely reflect their high abundance within the gut bacterial community and the role of clostridia in fiber digestion. The results illustrate the limitations of relying solely on cultivation to assess bacterial changes and illustrate that community changes are complex in an ecosystem containing high numbers of interdependent and competing species of bacteria.
- Subjects :
- Animals
Bacteria genetics
Bacteria isolation & purification
Bacteroides drug effects
Bacteroides growth & development
Bifidobacterium genetics
Bifidobacterium isolation & purification
Cloning, Molecular
Clostridium classification
Clostridium drug effects
Clostridium growth & development
DNA genetics
DNA isolation & purification
DNA, Bacterial genetics
DNA, Bacterial isolation & purification
Digestion
Phylogeny
Polymerase Chain Reaction
RNA, Bacterial genetics
RNA, Bacterial isolation & purification
RNA, Ribosomal, 16S genetics
RNA, Ribosomal, 16S isolation & purification
Rats
Dietary Fiber pharmacology
Feces microbiology
Subjects
Details
- Language :
- English
- ISSN :
- 1541-6100
- Volume :
- 139
- Issue :
- 11
- Database :
- MEDLINE
- Journal :
- The Journal of nutrition
- Publication Type :
- Academic Journal
- Accession number :
- 19776187
- Full Text :
- https://doi.org/10.3945/jn.109.109470