Probiotics: Not Just for Treatment Anymore

Probiotics, microorganisms that can have positive health effects when ingested, are increasingly studied and used in humans. Thus far, they have shown particular promise in the treatment of acute infectious diarrhea and the prevention of antibiotic-associated diarrhea, associations that have been investigated widely and have been subject to systematic review.^1–4 Other conditions potentially treatable by probiotics include chronic diarrhea,⁵ inflammatory bowel disease,⁶ irritable bowel syndrome,⁷ and food allergy⁸; potentially preventable conditions range from travelers’ diarrhea⁹ and necrotizing enterocolitis¹⁰ to urogenital infections,¹¹ atopic diseases,¹² and dental caries.¹³ Vanderhoof¹⁴ and other leaders in the field propose future applications in cystic fibrosis, rheumatoid arthritis, and cancers.

The study reported by Weizman et al¹⁵ in this issue of Pediatrics is one of a handful of randomized, controlled trials that have examined probiotics as a prevention for acute infectious illnesses in otherwise healthy infants and children.^16–20 This study aims to investigate whether a so-called functional food, infant formula containing either Bifidobacterium lactis or Lactobacillusreuteri, can decrease the risk of diarrhea, respiratory symptoms, fever, and other “morbidity parameters” when compared with a placebo formula. This represents a plausible future real-world scenario: infants attending child care centers, who may be at increased risk of these illnesses, could receive regular prophylaxis in the form of probiotic formula. The authors report a decrease in the numbers of episodes and numbers of days of both diarrhea and fever in the probiotic groups when compared with the placebo group. For example, the subjects in the placebo, B lactis, and L reuteri groups averaged 0.59, 0.37, and 0.15 days with diarrhea (presumably per child during the 12-week study period), respectively. This finding is interesting, although …

Address correspondence to Cornelius W. Van Niel, MD, Sea Mar Community Health Centers, 8720 14th Ave S, Seattle, WA 98108. E-mail: cvanniel{at}u.washington.edu