The effects of antimicrobial agents upon choline degradation in the intestinal tract.

A variety of intestinal bacteria have been shown to be capable of degrading choline to trimethylamine (1-3) which is readily absorbed from the intestine and excreted in the urine mainly as trimethylamine oxide. When a relatively large amount of choline is ingested by normal persons, about 60 per cent appears in the urine as total trimethylamines (TTMA), mostly within 24 hours (3). Part of the evidence gathered to establish this phenomenon was that, following ingestion of choline with aureomycin, much less TTMA than usual were excreted (3, 4). Further experiments were undertaken to elaborate upon the inhibition of TTMA formation from choline by antimicrobial agents. Several antimicrobial agents were administered in single therapeutic doses simultaneously with choline to determine whether they exhibited an effect similar to aureomycin. The period of suppression of bacterial degradation of choline was explored by allowing a time interval between the ingestion of the antibiotics and the choline. The development of bacterial resistance to the suppressive effect was studied by the protracted administration of an antibiotic in conjunction with repeated ingestion of choline.