Deconjugation of Bile Acids by Intestinal Bacteria: Review of Literature and Additional Studies

Shimada, Kaoru; Bricknell, Kenneth S.; Finegold, Sydney M.

doi:10.1093/infdis/119.3.273

Cited by 119 publications

(34 citation statements)

References 22 publications

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“…As for the substrate specificity of bacterial BSH, there are reports of some strains capable of splitting glycine conjugates only (I, 2, 15, 18) and of some strains hydrolyzing taurine conjugates only (2,22). In this study, the BSH from B. fragilis 2536 and C. peifringens PB 6K showed equal activity against glycine and taurine conjugates and hydrolyzed the conjugates of CA, CDCA, and DCA almost equally.…”

Section: Discussionmentioning

confidence: 58%

“…Microbial deconjugation of bile salts has been tested in most cases in growing cultures of the test strains, as in the tests for other kinds of bile acid metabolism (2,13,15,22). Deconjugation has also been studied in cell-free extracts from C. perfringens (1, 17) and B. Jragilis (1,23), but only a few reports of deconjugation by resting cells are available (4,10,23).…”

Section: Discussionmentioning

confidence: 99%

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Deconjugation of Bile Salts by Bacteroides and Clostridium

Masuda

1981

Microbiology and Immunology

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Deconjugation of bile salts by four strains of Bacteroides and four strains of Clostridium was studied by use of resting cells and cell-free culture supernatants. Bacteroides strains yielded active cells but showed relatively low bile salt hydrolase (BSH) activity in the culture supernatants while the reverse was the case for the spore-forming clostridial strains.BSH was formed constitutively and was oxygen insensitive. The optimum pH was between 4.5 and 5.0. Marked substrate specificity was found in two strains, one Clostridium and one Bacteroides, which showed restricted activity against taurine conjugates. Bacteroides in general attacked the taurine conjugates of dihydroxy bile acids more readily than the trihydroxy taurine conjugates.Deconjugated bile acid moieties were further modified by some resting cells, depending on the bacterial strain while no enzymatic activity other than that of BSH was found in the culture supernatants. Cells of B. fragilis 2536 performed 7a-dehydrogenation when the pH of the medium allowed the reaction, and this oxidative process was markedly enhanced in the presence of an abundant supply of oxygen as a terminal electron acceptor. C. perfringens PB 6K produced the 3-keto product in addition to the 3,B-hydroxy derivative of the liberated bile acids and the formation of the latter derivative seemed to take place without preliminary deconjugation.

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Section: Discussionmentioning

confidence: 58%

Section: Discussionmentioning

confidence: 99%

Deconjugation of Bile Salts by Bacteroides and Clostridium

Masuda

1981

Microbiology and Immunology

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“…Specifically, bacterial transformation of steroidal hormones has been reported to occur in a wide range of bacteria, including Clostridium (7,28). Normal gut bacteria also metabolize bile salts (40,49), a process that has been implicated in the control of C. difficile infections (21). Furthermore, changes in progesterone and glucocorticoid levels have been implicated in modulating infectious disease susceptibility and progression (59).…”

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confidence: 99%

Progesterone Analogs Influence Germination of Clostridium sordellii and Clostridium difficile Spores In Vitro

et al. 2011

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Clostridium sordellii and Clostridium difficile are closely related anaerobic Gram-positive, spore-forming human pathogens. C. sordellii and C. difficile form spores that are believed to be the infectious form of these bacteria. These spores return to toxin-producing vegetative cells upon binding to small molecule germinants. The endogenous compounds that regulate clostridial spore germination are not fully understood. While C. sordellii spores require three structurally distinct amino acids to germinate, the occurrence of postpregnancy C. sordellii infections suggests that steroidal sex hormones might regulate its capacity to germinate. On the other hand, C. difficile spores require taurocholate (a bile salt) and glycine (an amino acid) to germinate. Bile salts and steroid hormones are biosynthesized from cholesterol, suggesting that the common sterane structure can affect the germination of both C. sordellii and C. difficile spores. Therefore, we tested the effect of sterane compounds on C. sordellii and C. difficile spore germination. Our results show that both steroid hormones and bile salts are able to increase C. sordellii spore germination rates. In contrast, a subset of steroid hormones acted as competitive inhibitors of C. difficile spore germination. Thus, even though C. sordellii and C. difficile are phylogenetically related, the two species' spores respond differently to steroidal compounds.

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“…This deconjugation reaction is catalyzed by the enzyme bile salt hydrolase (BSH). BSH activity has been detected in many members of the autochthonous microflora of the gastrointestinal tract, including species of the genera Lactobacillus (7), Bacteroides (16,18), Clostridium (16,18), Streptococcus (13), Bifidobacterium (6,21), Fusobacterium (21), and others (4,17). The activity has been examined in cells and crude cell extracts from strains of several of these genera (1,13,16).…”

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confidence: 99%

Characterization and purification of bile salt hydrolase from Lactobacillus sp. strain 100-100

Lundeen

Savage

1990

J Bacteriol

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We have characterized and purified the bile salt hydrolase from Lactobacillus sp. strain 100-100. Bile salt hydrolase from cells of the strain was purified with column and high-performance liquid chromatography. The activity was assayed in whole cells and cell-free extracts with either a radiochemical assay involving ['4C]taurocholic acid or a nonradioactive assay involving trinitrobenzene sulfonate. The activity was detectable only in stationary-phase cells. Within 20 min after conjugated bile acids were added to stationary-phase cultures of strain 100-100, the activity in whole cells increased to levels three-to fivefold higher than in cells from cultures grown in medium free of bile salts. In cell-free extracts, however, the activity was about equal, 1.41 and 1.53 ,umol/min per mg of protein, respectively, whether or not the cells have been grown with bile salts present. When supernatant solutions from cultures grown in medium containing taurocholic acid were used to suspend cells grown in medium free of the bile salt, the bile salt hydrolase activity detected in whole cells increased two-to threefold. Two forms of the hydrolase were purified from the cells and designated hydrolases A and B. They eluted from anion-exchange high-performance liquid chromatography in two sets of fractions, A at 0.15 M NaCl and B at 0.18 M NaCl. Their apparent molecular weights in nondenaturing polyacrylamide gel electrophoresis were 115,000 and 105,000, respectively. However, discrepancies existed in the apparent molecular weights and number of peptides detected in sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the two forms. Both had similar substrate specificities, highest on taurodeoxycholic and glycocholic acid, and pH optima between 3.8 and 4.5. The kinetic properties were also similar, with Vmaxs of 17 and 53 ,Lmol/min per mg of protein and Kms of 0.76 and 0.95 mM taurocholic acid for A and B, respectively.

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Deconjugation of Bile Acids by Intestinal Bacteria: Review of Literature and Additional Studies

Cited by 119 publications

References 22 publications

Deconjugation of Bile Salts by Bacteroides and Clostridium

Deconjugation of Bile Salts by Bacteroides and Clostridium

Progesterone Analogs Influence Germination of Clostridium sordellii and Clostridium difficile Spores In Vitro

Characterization and purification of bile salt hydrolase from Lactobacillus sp. strain 100-100

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