Breakthrough Lactobacillus rhamnosus GG bacteremia associated with probiotic use in an adult patient with severe active ulcerative colitis: case report and review of the literature

Probiotics are widely investigated in the treatment of various bowel diseases. However, they may also have a pathogenic potential, and the role of Lactobacillus spp. as opportunistic pathogens, mostly following disruption of the intestinal mucosa, is emerging. We report on a case of bacteremia caused by L. rhamnosus GG in an adult patient affected by severe active ulcerative colitis under treatment with corticosteroids and mesalazine. Lactobacillus bacteremia was associated with candidemia and occurred while the patient was receiving a probiotic formulation containing the same strain (as determined by PFGE typing), and was being concomitantly treated with i.v. vancomycin, to which the Lactobacillus strain was resistant. L. rhamnosus GG bacteremia, therefore, was apparently related with translocation of bacteria from the intestinal lumen to the blood. Pending conclusive evidence, use of probiotics should be considered with caution in case of active severe inflammatory bowel diseases with mucosal disruption.