Chemical transformations of bile salts by the intestinal microflora

Eldere, J. Van

doi:10.1007/978-1-4757-3021-0_12

Cited by 3 publications

(2 citation statements)

References 114 publications

(66 reference statements)

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“…Weight gain in chickens in inversely correlated with intestinal Bsh activity, much of which comes from the dominant lactobacillus species in poultry, L. salivarius (26). Excessive deconjugation of bile in the gut may be linked with "contaminated small bowel syndrome" (22,58). Thus, it may be significant that L. salivarius strain UCC118, selected as a human probiotic, has low Bsh activity but high overall bile resistance.…”

Section: Discussionmentioning

confidence: 99%

Allelic Variation of Bile Salt Hydrolase Genes in Lactobacillus salivarius Does Not Determine Bile Resistance Levels

Fang

Bumann³

et al. 2009

J Bacteriol

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Commensal lactobacilli frequently produce bile salt hydrolase (Bsh) enzymes whose roles in intestinal survival are unclear. Twenty-six Lactobacillus salivarius strains from different sources all harbored a bsh1 allele on their respective megaplasmids. This allele was related to the plasmid-borne bsh1 gene of the probiotic strain UCC118. A second locus (bsh2) was found in the chromosomes of two strains that had higher bile resistance levels. Four Bsh1-encoding allele groups were identified, defined by truncations or deletions involving a conserved residue. In vitro analyses showed that this allelic variation was correlated with widely varying bile deconjugation phenotypes. Despite very low activity of the UCC118 Bsh1 enzyme, a mutant lacking this protein had significantly lower bile resistance, both in vitro and during intestinal transit in mice. However, the overall bile resistance phenotype of this and other strains was independent of the bsh1 allele type. Analysis of the L. salivarius transcriptome upon exposure to bile and cholate identified a multiplicity of stress response proteins and putative efflux proteins that appear to broadly compensate for, or mask, the effects of allelic variation of bsh genes. Bsh enzymes with different bile-degrading kinetics, though apparently not the primary determinants of bile resistance in L. salivarius, may have additional biological importance because of varying effects upon bile as a signaling molecule in the host.

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Section: Discussionmentioning

confidence: 99%

Allelic Variation of Bile Salt Hydrolase Genes in Lactobacillus salivarius Does Not Determine Bile Resistance Levels

Fang

Bumann³

et al. 2009

J Bacteriol

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“…It has been proposed that the metabolic activity of L. salivarius in the broiler small bowel reduces concentrations of conjugated bile salts (taurocholate and taurochenodeoxycholate), impairing lipid absorption and leading to reduced weight gain (8). This is analogous to "contaminated small bowel syndrome" in humans (6,29), in which overgrowth of bacteria that produce bile salt hydrolase results in steatorrhea and weight loss due to impaired digestion and absorption of dietary lipid. Antibiotic therapy results in reduction of symptoms (6).…”

mentioning

confidence: 99%

Real-Time Quantitative PCR Measurement of Ileal Lactobacillus salivarius Populations from Broiler Chickens To Determine the Influence of Farming Practices

Harrow

Ravindran

Butler

et al. 2007

Appl Environ Microbiol

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A real-time quantitative PCR assay targeting a 16S-23S intergenic spacer region sequence was devised to measure the sizes of populations of Lactobacillus salivarius present in ileal digesta collected from broiler chickens. This species has been associated with deconjugation of bile salts in the small bowel and reduced broiler productivity. The assay was tested as a means of monitoring the sizes of L. salivarius populations from broilers fed diets with different compositions, maintained at different stocking densities, or given the antimicrobial drugs bacitracin and monensin in the feed. Stocking densities did not influence the numbers of L. salivarius cells in the ileum. A diet containing meat and bone meal reduced the size of the L. salivarius population relative to that of chickens given the control diet, as did administration of bacitracin and monensin in the feed. These changes in the target bacterial population were associated with improved broiler weight gain.

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Nanoscale and customary non‐esterified sitosterols are equally enriched in different body compartments of the guinea pig

Keller

Helbig

Härtl

et al. 2007

Molecular Nutrition Food Res

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The impact of sitosterol formulation particle size on the intestinal sterol absorption and the sterol status in various tissues in Dunkin Hartley guinea pigs was investigated. Three groups of animals (six each) were fed a basal diet ("control") or a basal diet containing either customary sitosterol ("customary", particle size: 10 000-90 000 nm) or nanoscale sitosterol ("nanoscale", particle size: 200-300 nm). The average daily sitosterol intake was 21 +/- 7 mg (control), 154 +/- 8 mg (customary), and 127 +/- 18 mg (nanoscale) for 2 weeks. Sitosterol and cholesterol were analyzed in samples of plasma, blood cells, bile, liver, kidney, jejunal mucosa/serosa, cecum, colon and feces. Concentrations of sitosterol in all analyzed matrices increased significantly in the supplemented groups when compared to control group. No differences in the sitosterol concentrations in analyzed matrices occurred between nanoscale and customary group. The cholesterol concentrations in tissues remained unchanged. Fecal fatty acid and sterol distributions were modified during sitosterol intervention. Both particle sizes equally increased sitosterol levels in cholesterol-metabolizing compartments in the guinea pig. No differences in body compartment accumulation and intestinal absorption of the different sitosterol particle sizes were observed.

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Chemical transformations of bile salts by the intestinal microflora

Cited by 3 publications

References 114 publications

Allelic Variation of Bile Salt Hydrolase Genes in Lactobacillus salivarius Does Not Determine Bile Resistance Levels

Allelic Variation of Bile Salt Hydrolase Genes in Lactobacillus salivarius Does Not Determine Bile Resistance Levels

Real-Time Quantitative PCR Measurement of Ileal Lactobacillus salivarius Populations from Broiler Chickens To Determine the Influence of Farming Practices

Nanoscale and customary non‐esterified sitosterols are equally enriched in different body compartments of the guinea pig

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