pH and peptide supply can radically alter bacterial populations and short-chain fatty acid ratios within microbial communities from the human colon

被引:570
作者
Walker, AW
Duncan, SH
Leitch, ECM
Child, MW
Flint, HJ
机构
[1] Rowett Res Inst, Microbial Genet Grp, Aberdeen AB21 9SB, Scotland
[2] Univ Dundee, Microbiol & Gut Biol Grp, Dundee, Scotland
关键词
D O I
10.1128/AEM.71.7.3692-3700.2005
中图分类号
Q81 [生物工程学(生物技术)]; Q93 [微生物学];
学科分类号
071005 ; 0836 ; 090102 ; 100705 ;
摘要
The effects of changes in the gut environment upon the human colonic microbiota. are poorly understood. The response of human fecal microbial communities from two donors to alterations in pH (5.5 or 6.5) and peptides (0.6 or 0.1%) was studied here in anaerobic continuous cultures supplied with a mixed carbohydrate source. Final butyrate concentrations were markedly higher at pH 5.5 (0.6% peptide mean, 24.9 mM; 0.1% peptide mean, 13.8 mM) than at pH 6.5 (0.6% peptide mean, 5.3 mM; 0.1% peptide mean, 7.6 mM). At pH 5.5 and 0.6% peptide input, a high butyrate production coincided with decreasing acetate concentrations. The highest propionate concentrations (mean, 20.6 mM) occurred at pH 6.5 and 0.6% peptide input. In parallel, major bacterial groups were monitored by using fluorescence in situ hybridization with a panel of specific 16S rRNA probes. Bacteroides levels increased from ca. 20 to 75% of total eubacteria after a shift from pH 5.5 to 6.5, at 0.6% peptide, coinciding with high propionate formation. Conversely, populations of the butyrate-producing Roseburia group were highest (11 to 19%) at pH 5.5 but fell at pH 6.5, a finding that correlates with butyrate formation. When tested in batch culture, three Bacteroides species grew well at pH 6.7 but poorly at pH 5.5, which is consistent with the behavior observed for the mixed community. Two Roseburia isolates grew equally well at pH 6.7 and 5.5. These findings suggest that a lowering of pH resulting from substrate fermentation in the colon may boost butyrate production and populations of butyrate-producing bacteria, while at the same time curtailing the growth of Bacteroides spp.
引用
收藏
页码:3692 / 3700
页数:9
相关论文
共 57 条
[11]   Compared effects of three oligosaccharides on metabolism of intestinal microflora in rats inoculated with a human faecal flora [J].
Djouzi, Z ;
Andrieux, C .
BRITISH JOURNAL OF NUTRITION, 1997, 78 (02) :313-324
[12]   Contribution of acetate to butyrate formation by human faecal bacteria [J].
Duncan, SH ;
Holtrop, G ;
Lobley, GE ;
Calder, AG ;
Stewart, CS ;
Flint, HJ .
BRITISH JOURNAL OF NUTRITION, 2004, 91 (06) :915-923
[13]  
Duncan SH, 2002, INT J SYST EVOL MICR, V52, P2141, DOI [10.1099/ijs.0.02241-0, 10.1099/00207713-52-6-2141]
[14]   Acetate utilization and butyryl coenzyme A (CoA):acetate-CoA transferase in butyrate-producing bacteria from the human large intestine [J].
Duncan, SH ;
Barcenilla, A ;
Stewart, CS ;
Pryde, SE ;
Flint, HJ .
APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 2002, 68 (10) :5186-5190
[15]   Effects of alternative dietary substrates on competition between human colonic bacteria in an anaerobic fermentor system [J].
Duncan, SH ;
Scott, KP ;
Ramsay, AG ;
Harmsen, HJM ;
Welling, GW ;
Stewart, CS ;
Flint, HJ .
APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 2003, 69 (02) :1136-1142
[16]   Lactate-utilizing bacteria, isolated from human feces, that produce butyrate as a major fermentation product [J].
Duncan, SH ;
Louis, P ;
Flint, HJ .
APPLIED AND ENVIRONMENTAL MICROBIOLOGY, 2004, 70 (10) :5810-5817
[17]  
DUNCAN SH, 2002, INT J SYST EVOL MICR, V52, P1
[18]   Probiotics and the management of inflammatory bowel disease [J].
Fedorak, RN ;
Madsen, KL .
INFLAMMATORY BOWEL DISEASES, 2004, 10 (03) :286-299
[19]  
Franks AH, 1998, APPL ENVIRON MICROB, V64, P3336
[20]   DIETARY MODULATION OF THE HUMAN COLONIC MICROBIOTA - INTRODUCING THE CONCEPT OF PREBIOTICS [J].
GIBSON, GR ;
ROBERFROID, MB .
JOURNAL OF NUTRITION, 1995, 125 (06) :1401-1412