Interaction of bismuth subsalicylate with fruit juices, ascorbic acid, and thiol-containing substrates to produce soluble bismuth products active against Clostridium difficile.

Bismuth subsalicylate (BSS), the active ingredient of Pepto-Bismol, has been used for many years to treat various disorders of the gastrointestinal tract. Using mass spectrometry and the agar dilution method, we determined that insoluble BSS interacts with certain dietary components and organic substrates to produce water-soluble products with activity against Clostridium difficile.