Effect of coprophagy prevention and antibiotics on choline degradation in rats.

Total trimethylamine (TTMA) in urine arising from intestinal micro- flora acting upon a test dose of choline given by gastric intubation was measured so as to evaluate the relative effectiveness of several conditions known to affect intestinal microflora. Preventing coprophagy lowered the urinary TTMA considerably. Dietary supplements of chlortetracycline (CTC) or phthalylsulfathiazole (PST) reduced TTMA slightly more effectively than coprophagy prevention. Rats receiving a combination of CTC and PST were affected to a greater extent than those receiving either CTC or PST alone. Penicillin (PEN) alone had little or no effect upon choline degradation. However, a combination of PEN and PST showed remarkable synergistic effect for the inhibition of TTMA excretion, an effect greater than for any other treatment studied. It is believed that microbial degradation of choline in the rat takes place mostly in the lower part of the intestine but the extent of this degradation may be greatly modified by changes in the bacterial population of the upper intestinal tract.