title: Role of intestinal microbiota in transformation of bismuth and other metals and metalloids into volatile methyl and hydride derivatives in humans and mice.
abstract: The present study shows that feces samples of 14 human volunteers and isolated gut segments of mice (small intestine, cecum, and large intestine) are able to transform metals and metalloids into volatile derivatives ex situ during anaerobic incubation at 37 degrees C and neutral pH. Human feces and the gut of mice exhibit highly productive mechanisms for the formation of the toxic volatile derivative trimethylbismuth [(CH(3))(3)Bi] at rather low concentrations of bismuth (0.2 to 1 mumol kg(-1) [dry weight]). An increase of bismuth up to 2 to 14 mmol kg(-1) (dry weight) upon a single (human volunteers) or continuous (mouse study) administration of colloidal bismuth subcitrate resulted in an average increase of the derivatization rate from approximately 4 pmol h(-1) kg(-1) (dry weight) to 2,100 pmol h(-1) kg(-1) (dry weight) in human feces samples and from approximately 5 pmol h(-1) kg(-1) (dry weight) to 120 pmol h(-1) kg(-1) (dry weight) in mouse gut samples, respectively. The upshift of the bismuth content also led to an increase of derivatives of other elements (such as arsenic, antimony, and lead in human feces or tellurium and lead in the murine large intestine). The assumption that the gut microbiota plays a dominant role for these transformation processes, as indicated by the production of volatile derivatives of various elements in feces samples, is supported by the observation that the gut segments of germfree mice are unable to transform administered bismuth to (CH(3))(3)Bi.
authors: Department of Microbiology, University of Duisburg-Essen, Universitaetsstr. 5, 45117 Essen, Germany. klaus.michalke@uni-due.de
authors: Klaus
authors: K
authors: Michalke
authors: Annette
authors: A
authors: Schmidt
authors: Britta
authors: B
authors: Huber
authors: Jörg
authors: J
authors: Meyer
authors: Margareta
authors: M
authors: Sulkowski
authors: Alfred V
authors: AV
authors: Hirner
authors: Jens
authors: J
authors: Boertz
authors: Frank
authors: F
authors: Mosel
authors: Philip
authors: P
authors: Dammann
authors: Gero
authors: G
authors: Hilken
authors: Hans J
authors: HJ
authors: Hedrich
authors: Martina
authors: M
authors: Dorsch
authors: Albert W
authors: AW
authors: Rettenmeier
authors: Reinhard
authors: R
authors: Hensel
mesh_terms: D000328:Adult; D000818:Animals; D001711:Biotransformation; D002432:Cecum / Q000382:microbiology; D005243:Feces / Q000737:chemistry / Q000382:microbiology; D041981:Gastrointestinal Tract / Q000382:microbiology*; D006801:Humans; D008658:Inactivation, Metabolic; D007420:Intestine, Large / Q000382:microbiology; D007421:Intestine, Small / Q000382:microbiology; D008297:Male; D008670:Metals / Q000378:metabolism*; D051379:Mice; D008809:Mice, Inbred C3H
chemical_list: D008670:Metals