The purpose of this study is to determine the effectiveness of commercially available kefir on preventing antibiotic-associated diarrhea compared to placebo in children ages 1-5.

Diarrhea is a common and costly disease of children in the United States. Children less than 5 years of age experience 20-35 million episodes of diarrhea per year. These episodes lead to 2-3.5 million physician visits (which account for 10% of all visits), more than 200,000 hospitalizations (13% of hospital admissions in children less than 5 years), and 325-425 deaths annually. In 1991, the outpatient costs of treating diarrhea for children under age 3 were calculated at 0.6-1 billion dollars per year.

Acute diarrhea in young children is almost always caused by infections or antibiotics. The rate of diarrhea associated with antibiotic usage is 20-35%, with children 3-36 months receiving on average 2-3 antibiotic prescriptions per year. Studies have shown that diarrhea due to either antibiotics or infections is caused by disturbances of the microflora of the gastrointestinal tract.

The current treatment for diarrhea in young children is oral rehydration, which is used to treat dehydration but plays no role in prevention. Probiotics are live microorganisms which, when administered in sufficient amounts, may improve health. Probiotics have the potential to treat and prevent diarrhea by improving the intestinal flora when disturbed by events such as antibiotics. Important to their use is that they are of human origin, survive passage through the gut, and are safe in very large dosages.

Studies have examined the potential health benefits of probiotics in the prevention and treatment of both antibiotic and infectious diarrhea. The probiotics have generally been given as supplements or pills. In placebo controlled randomized studies using these techniques, probiotics have generally been shown to decrease antibiotic associated diarrhea by 15-25% over placebo. Other studies have enrolled children with acute diarrhea, generally from rotavirus, and found a 30-50% cure rate in the probiotic group over placebo.

Kefir, available in the United States, is a milk product derived by the action of ten probiotics. A daily dose of 10^6-10^9 colony forming units of probiotics has been studied and recommended for health benefits.

Inclusion Criteria:

• Ability to speak and write English
• Aged 1-5 years
• Male or female
• Diagnosed with an upper respiratory infection and placed on a penicillin class antibiotic regimen for 10 days

Exclusion Criteria:

• Developmental delays
• Chronic conditions, such as diabetes or asthma, that require medication
• Prematurity, birth weight <2500 grams
• Allergy to kefir and/or milk
• Active diarrhea
• Congenital anomalies
• Failure to thrive
• Parental belief of lactose intolerance

We did not assess or culture stools for the presence of pathogenic organisms. We did not independently examine children; we relied on parental/patient-oriented outcomes. Our population was generally very healthy. We did not assess probiotic dosages.