Valerie Sung paediatrician, Harriet Hiscock associate professor, Mimi L K Tang professor, Fiona K Mensah statistician, Monica L Nation honours student, Catherine Satzke research fellow et al
Sung V, Hiscock H, Tang M L K, Mensah F K, Nation M L, Satzke C et al.
Treating infant colic with the probiotic Lactobacillus reuteri: double blind, placebo controlled randomised trial
BMJ 2014; 348 :g2107
doi:10.1136/bmj.g2107
Re: Treating infant colic with the probiotic Lactobacillus reuteri: double blind, placebo controlled randomised trial
Comment on Sung Study: HELP THE HAMMER TO FIND THE NAIL: PLEASE AVOID THE “FOGGY ZONE”
I read with interest the article of Dr Sung on the treatment of infant colic with probiotics.
This is a large study but not the largest and the study is not rigorous as the authors state several times.
The children included in study were extremely heterogeneous. Sixty percent had a familial history of allergy and it is well known that allergically predisposed children have a totally different microbiota. More than 30% of the babies were treated with a proton pump inhibitor that would change dramatically the intestinal microbiota.
A further factor that does not allow any clear message from the study is the fact that 35% of the children studied already had a probiotic-containing formula and that 15% of the formula-fed children are assumed to had hypoallergenic formula.
The formula-fed children will have had a different intestinal microbiota because of the different milk formula used. In this heterogenous background, how could the effect of supplementation with the Lactobacillus reuteri be expected to be seen? Even though the authors used a regression analysis to extrapolate the data, such an analysis does not allow the exclusion of the confounding variable effects. The same is valid for the values of fecal calprotectin reported. For example, if the children included in the placebo group were taking formula with added probiotic, the calprotectin value might be lower due to an effect of the probiotic in the milk.
On the other hand, if the children included in the probiotic-supplemented group had a positive familial history of allergy, the calprotectin value might be higher due to this risk factor. In our study on profhilactic use of Lactobacillus reuterii on colic regurgitation and constipation, the largest study, we enrolled a healthy population with strict exclusion criteria and so was possible to perform a rigorous study. It is clear that the babies enrolled were not “healthy term infants” as stated in the Methods, but rather more than 70% were recruited in the emergency or urgent care setting which introduces a bias in the selected population.
The authors state that the use of a baby diary permitted a detailed analysis. Were the parent assisted during the month of the compilation of the diary by a doctor? Parents with an crying baby are extremely stressed and need strong support to handle the difficult baby let alone to fill in the diary.
At this time, when the scientific evidence and literature on probiotic effects are more rigorous and with the removal of any confounding variables, communicating recommendations based on this study of an extremely variable and non-homogeneous study population, is, in the least naïve and, one could even say, “vintage”.
The fog that cover this article makes impossible for any hammer to find the nail.
Competing interests: No competing interests