Yakult’s Lactobacillus casei strain Shirota was tested in 3,758 children aged between one and five years old, and in addition to the reduction in diarrhea risk, the researchers also note no adverse events in children receiving the daily probiotic supplement. The study was funded by Yakult Honsha.
“This study provides evidence of a significant preventive effect of a probiotic on acute diarrhea in children aged between 1 and 5 years in an urban slum community in a developing country,” wrote the researchers in Epidemiology and Infection.
“We believe that this study is one of the largest of this kind,” they added.
The study was led by scientists from the National Institute of Cholera and Enteric Diseases in Kolkata in association with scientists from the Yakult Central Institute for Microbiological Research in Japan.
This is not the first time that probiotics have been reported to reduce the incidence of diarrhea. Indeed, a meta-analysis of randomized, placebo-controlled trials published in the Lancet Infectious Diseases (2006, Vol. 6, pp. 374-382) may reduce the risk of acute diarrhea by 34 percent.
“Although there is some suggestion that probiotics may be efficacious in preventing acute diarrhea, there is lack of sufficient data from community-based trials, especially from developing countries, to assess the effect on acute diarrhea unrelated to antibiotic usage,” stated the scientists.
In order to fill in some of the gaps in this area, the Kolkata-based researchers performed a double-blind, randomized, controlled field trial in an urban slum community in Kolkata, India.
Children aged between one and five were randomly assigned to receive either a drink containing 6.5 billion units of L. casei strain Shirota or a drink containing a mix of nutrients for 12 weeks. The children were followed for a further 12 weeks after the end of the intervention.
At the end of 24 weeks of study, a total of 608 cases of diarrhea had been documented in the probiotic group, compared with 674 in the nutrient drink group. The probiotic drink was therefore associated with a 14 percent reduction in the risk of diarrhea.
“[L. casei strain Shirota] is reported to have several beneficial effects on gastrointestinal disturbances including some forms of diarrhea and related diseases and is reported to improve the balance of micro- flora as well as bowel movement frequency and stool consistency,” stated the researchers.
“It also promotes proliferation of phagocytes such as macrophages and neutrophils in the bone marrow and spleen thus activating the innate immune system which in turn is important in the infection-preventing effect of the probiotic,” they added.
The other researchers were affiliated with the Collaborative Research Center of Okayama University for Infectious Diseases in India and the Indian Council of Medical Research.
Source: Epidemiology and Infection
Published online ahead of print, doi: 10.1017/S0950268810001780
“Role of probiotic in preventing acute diarrhoea in children: a community-based, randomized, double-blind placebo-controlled field trial in an urban slum”
Authors: D. Sur, B. Manna, S. K. Niyogi, et al.