AbstractWe studied the effects ofBifidobacterium breveon Campylobacter enteritis. Patients with Campylobacter enteritis were divided into three groups (I. Erythromycin recipients; II.B. breverecipients; III. control) and studied with regard to the duration of diarrhea and carriage ofCampylobacter jejuniin the stools. Additional studies were performed to observe the effects ofB. breve onfecal flora. The results showed that there were no significant differences in the duration of diarrhea among the three groups. Comparison of the duration ofC. jejunicarriage in the stools was as follows: KIKIII (P<0.01). Microbiological study of fecal flora demonstrated that the number of bifidobacterium was decreased in Campylobacter enteritis compared to the control, and an increase in the number of bifidobacterium could be recognized after the administration ofB. breve. B. brevewas useful in eradicatingC. jejunifrom the stools and restoring the normal intestinal flora in Campylobacter enteritis, although if was not effective in shortening the duration of diarrhea.