The meta-analysis, published in this week's The Lancet, carried out randomised controlled trials including 1393 premature infants and a variety of probiotics. In addition to a reduced risk of necrotising enterocolitis, they also observed a 53 per cent reduction in the risk of mortality.
"The remarkably consistent results, despite the distinct differences in dose, timing, and type of organisms used, suggest that substantial latitude might be available in the choice of an effective probiotic regimen in the design of further trials," wrote the authors.
"If a large well-designed trial confirms our results, it could make a very strong case for the routine use of probiotics in preterm neonates," they added.
The researchers, led by Girish Deshpande from King Edward Memorial Hospital for Women, carried out seven randomised controlled trials on subjects that met their inclusion criteria.
Pooling the data showed that probiotic supplementation reduced the risk of necrotising enterocolitis by 74 per cent, compared to controls. The risk of death was reduced by 53 per cent in the probiotic group, compared to control. The time taken for the premature infants to start full feeding was also reduced by about three days.
"Probiotics might reduce the risk of necrotising enterocolitis in preterm neonates with less than 33 weeks' gestation," concluded the researchers. "However, the short-term and long-term safety of probiotics needs to be assessed in large trials. Unanswered questions include the dose, duration, and type of probiotic agents (species, strain, single or combined, live or killed) used for supplementation."
In an accompanying editorial, Parma University's Carlo Caffarelli and Sergio Bernasconi welcomed the research as a positive step.
"Over the past few decades, the frequency of the condition has shown no sign of reduction," they wrote. "Therefore the development of strategies to prevent the disease is a priority."
However, Caffarelli and Bernasconi cautioned that the results needed to be interpreted with care.
"The meta-analysis by Deshpande and colleagues indicates that a wide range of questions needs to be addressed," they said. "The analyses were based on clinical trials that tested different probiotics, such as Lactobacillus acidophilus, L casei GG, L bulgaricus, Bifidobacterium bifidum, B breve, B infants, B lactis, Streptococcus thermophilus, and Saccharomyces boulardii. Each strain is believed to have specific immunomodulatory properties.
"The limited number of clinical trials does not permit definition of either the optimum strain or dosing regimens. The evidence of the effect of type of feeding and antibiotic therapy on gut colonisation is also unclear. Finally, trials included in the overview show a lack of side-effects," they added.
Source: The Lancet
12-18 May 2007, Volume 369, Issue 9573, Pages 1614-1620
"Probiotics for prevention of necrotising enterocolitis in preterm neonates with very low birthweight: a systematic review of randomised controlled trials"
Authors: G. Deshpande, S. Rao and S. Patole
Editorial: The Lancet
12-18 May 2007, Volume 369, Issue 9573, Pages 1578-1580
"Preventing necrotising enterocolitis with probiotics"
Carlo Caffarelli and Sergio Bernasconi
