35 bacterial strains isolated from the human faecal flora were screened for hydrolysis of the glucuronides of 3,3′,5-triiodothyronine and 3,3′-diiodothyronine. Two Gram-positive obligately anaerobic strains possessed glucuronidase activity. These strains probably belong to the genus Eubacterium, but ethanol was produced in high concentrations during glucose fermentation, which makes final classification difficult. Considering the number of bacteria in the intestinal flora (> 108/ml) and the biliary excretion of iodothyronine conjugates, the strains must be able to hydrolyse a major part of the total daily intestinal supply of these iodothyronine metabolites. The study extends previous observations with faecal suspensions of human and rat origin [24]. The relevance of bacterial β-glucuronidase activity for a possible enterohepatic circulation of iodothyronines is discussed.

Iodothyronine glucuronides, obligate anaerobes
dx.doi.org/10.1016/0378-1097(86)90101-1, hdl.handle.net/1765/127567
F E M S Microbiology Letters

de Herder, W.W, Hazenberg, M.P.H, Pennock-Schröder, A.M. (A. M.), Hennemann, G, & Visser, T.J. (1986). Hydrolysis of iodothyronine glucuronides by obligately anaerobic bacteria isolated from human faecal flora. F E M S Microbiology Letters, 35(2-3), 249–253. doi:10.1016/0378-1097(86)90101-1