Lactobacillus paracasei strain ST11 has no effect on rotavirus but ameliorates the outcome of nonrotavirus diarrhea in children from Bangladesh

Background. Previous studies have shown that selected strains of lactobacilli that are administered orally result in a modest reduction of diarrhea duration. However, duration alone is not considered optimal for therapeutic evaluation of any agent in diarrhea. Objective. To examine the effect of a new probiotic, Lactobacillus paracasei strain ST11 (ST11), in acute childhood diarrhea by using evaluation criteria recommended by the World Health Organization. Methods. In a randomized, double-blind, placebo-controlled clinical trial, 230 male infants and young children, 4 to 24 months of age, presenting with diarrhea of <2 days' duration were admitted to the metabolic research ward of the International Centre for Diarrheal Disease Research, Bangladesh, and fed 10¹⁰ colony-forming units of lyophilized ST11 or placebo daily for 5 days. Stool output and frequency, oral rehydration solution intake, and excretion of rotavirus were monitored daily. Results. No effect of ST11 treatment on severe rotavirus diarrhea was observed. However, the probiotic treatment did significantly reduce cumulative stool output (225 ± 218 vs 381 ± 240 mL/kg), stool frequency (27.9 ± 17 vs 42.5 ± 26), and oral rehydration solution intake (180 ± 207 vs 331 ± 236 mL/kg) in children with less-severe nonrotavirus diarrhea compared with those receiving placebo treatment. A significantly higher proportion of nonrotavirus children receiving ST11 had their diarrhea resolve within 6 days of therapy (ST11 versus placebo: 76% vs 49%). Conclusions. ST11 has a clinically significant benefit in the management of children with nonrotavirus-induced diarrhea, but it is ineffective in those with rotavirus diarrhea.