The concept of taking probiotic supplementation for better health and improving acute episodes of diarrhea has been well-known. Several studies have indicated that probiotic supplementation bring beneficial effects for patients with diarrhea. However, there is a striking lack of evidence on the supplementation of probiotic products in adult patients with acute diarrhea and prescribing probiotics for acute diarrhea has been underestimated. A prospective, double-blind, randomized, controlled clinical trial was conducted in adult patients who visited the study sites at three hospitals (Cipto Mangunkusumo, Koja and Tarakan Hospital) in Jakarta between 2007 and 2010. The subjects were divided into 2 groups, that is, the treatment group receiving Lactobacillusspp. product at the dose of 3 × 2 capsules for 7 days and the control group receiving placebo. Statistical analysis was performed using Statistical Package for the Social Sciences (SPSS) software program. The p value of < 0.05 was considered significant. The study demonstrated a significant result of faster recovery from diarrhea 1.02 ± 0.48 days sooner than the placebo group (p = 0.018). Greater improvement on clinical outcomes (frequency of stools, stool consistency, abdominal pain, nausea, vomiting, bloating, headache, fever and tenesmus) were observed in the group receivingLactobacillus spp. supplementation; however, the result was statistically significant on stool consistency only. Combined probiotic supplementation appears to be a promising therapeutic agent for treatment of acute diarrhea in adults. However, further controlled clinical studies as well as good storage, handling and distribution is essential to explore the therapeutic benefit for possible practical clinical application. Key words: Lactobacillus rhamnosus, Lactobacillus acidophilus, probiotic supplementation, acute diarrhea, adults.