Scientist - News - 24-09-2009:

Kefir: some intriguing findings
Beintema, Nienke

Kefir does not help to prevent antibiotics-associated diarrhea in children overall, but there may be some benefits for specific groups of children, according to a new study.

Young children are regularly prescribed antibiotics. Around 20 to 30 percent of children, however, develop diarrhea as a side-effect. Diarrhea can have serious health impacts, while the benefits of the antibiotics are often questionable. Although education of doctors and the general public has decreased the rate of antibiotics prescriptions, around 25 percent of all doctor’s visits for children younger than five years still esult in a prescription for antibiotics. In the US, children aged 3 to 36 months average more than two antibiotic prescriptions per year, with nearly 30 percent of them receiving more than four.
There has been some scientific evidence that probiotic bacteria can help prevent antibiotics-associated diarrhea. An American study at the Georgetown University Medical Center (Washington, DC) and at the University of Pittsburgh examined the effect of kefir, a traditional and widely available yoghurt-like product. This study appeared in the August issue of the journal Archives in Pediatric and Adolescent Medicine.

Poorer health
The team conducted a randomized, doubleblind, placebo-controlled study among 125 children aged between one and five years of age. These children had been prescribed antibiotics against respiratory tract infections. In addition to antibiotics, half of them consumed a daily portion of active kefir, and the other half received kefir in which the bacteria had been killed by a heat treatment. The active kefir contained nine probiotic strains, including Lactococcus rhamnosus, L. casei, Bifidobacterium breve and Lactobacillus acidophilus. The kefir was consumed for ten days.
The study found that 18 percent of children in the active kefir group developed diarrhea, compared to 22 percent in the placebo group – which is not a statistically significant difference. There was no difference either in secondary outcomes, such as runny nose, cough and fever. However, in children whose health was poorer at enrolment, 23 percent in the kefir group developed diarrhea, compared with 31 percent in the placebo group. Also, there was a marked difference among the older children in the study, aged three to five years: 6 percent of the active group developed diarrhea, versus 14 percent in the placebo group. Interestingly, the overall rates of diarrhea were much lower in these older children – and much lower in girls than in boys.

Small study
"Our theory is that kefir may not have helped healthy children that much because the extra immune system boost provided by the drink may not be necessary," writes lead author Daniel Merenstein on his special website for this study. "It is possible that kefir may have some benefit in specific groups. We have found with our other studies that in very healthy children the benefit of probiotics may be minute and difficult to elicit in small studies. That is why we need new larger studies in children to elicit who might benefit."

More information:
Article in Archives in Pediatric and Adolescent Medicine
Study website by lead author Merenstein