History and Objectives: Due to the prevalence of acute amebiasis and its known complications and considering various reports on the positive effect of Saccharomyces or prevention and treatment of infectious enteritis and in order to compare the antibiotic regimen alone and besides Saccharomyces in the treatment of acute amebiasis, this research was performed on referrers to Shaheed Beheshti hospital of Shiraz during the year 1371.

Materials and Methods: A clinical trial study was performed on 57 patients with acute intestinal amebiasis. The diagnosis of the disease was based on clinical manifestations and the presence of trophozoite of the Entamoeba in the stool specimen. Patients were classified in 2 therapeutic groups by random. In the control group, the routine antibiotic and in the experimental group oral leophilized capsules of Saccharomyces were added at a dose of 250 milligrams 3 times a day. The time of improvement of diarrhea, fever abdominal pain, headache and disappearance of trophozoite from the stool specimen wee considered as the effectiveness of the therapeutic regimen.

Results: From both groups, 3 patients refused to cooperate and fever eliminated from the study. The remaining 54 patients were divided into 2 groups each including 27 individuals. The 2 groups were similar in age/sex and the clinical manifestations .In the control group, diarrhea persisted for 48±18 hours and in the experimental group (Antibiotic plus Saccharomyces) 12±3.7 hours (P<0.0001). Fever and abdominal pain persisted for 24±8.8 and 24±7.3 hours in the control group and 12±5.3 and 12±3.2 hours in the experimental group respectively (P<0.001) but the duration of headache was similar in both groups. In the fourth week, Entamoeba cysts were detected in 5 patients (18.5%) in the control group but in none of the individuals in the experimental group (P<0.02).

Conclusion: Administrating Saccharomyces yeast besides antibiotic in acute amebiasis decreases the duration of illness and eliminates cysts excretion after treatment.