Affecting up to 20% of infants, colic usually resolves after the first 3-4 months—which may seem like years for parents– after birth. It is associated with maternal depression, abrupt stopping of breastfeeding and shaken baby syndrome.
Theories for the cause abound:
- The mother may interact poorly, may be depressed or the infant may be “difficult”.
- Some point to gastrointestinal problems: gas, gut inflammation, and visceral pain.
As no single treatment for colic exists, an effective, practical, and acceptable intervention for infant colic would represent a major advance in clinical and public health.
And so goes the scientific quest: One step forward and usually several sideways or even backwards before the truth is teased out.
Scientists in Melbourne at wondered whether a strain of Lactobacillus reuteri could reduce the intractable crying of colic in 167 breast fed and bottle fed infants; for one month, 85 were randomly chosen to receive the probiotic while 82 received a placebo.
At 1 month, the probiotic group cried or fussed 49 minutes more than the placebo group. Thus no benefit was seen from the addition of probiotics in this study.
It is wise to make conclusions based on a large breadth of research rather than making a statement or conclusion based only on one study.
The Australian study in question led by Sung used one specific species of probiotics; as such, it shouldn`t be interpreted that all probiotics would yield the same null effect. It is worthy to note that this same probiotic was shown to be efficacious in previous studies under different clinical settings. In addition, the study itself has limitations–also included in the report–that could affect outcomes.
- First, the study doesn`t specify whether there were underlying health issues that could have affected the study. This is a crucial point when making a study on infants recruited from emergency or urgent care settings. Interestingly, as many as 63% of infants met the inclusion criteria for the study. Considering that in general, only up to 25% of infants suffer from colic, the prevalence in this study is unusually high and one may wonder if the population suffered from disorders other than colic, and if those disorders also were the cause for the visit to the ER. So without the full diagnosis of causes for each visit being investigated, the possibility of it being something other than colic would complicate results. In addition, the description used to describe a colicky baby – behavior that is not quite crying but not awake and content either – seems to differ from the more widely accepted definition of colic: constant crying for more than 3 hours for more than 3 days in one week or more. This may have influenced the inclusion criteria in this setting.
- Second, from the researchers` data, potentially more than 50% of the placebo group could have been taking some form of probiotic supplementation during the study. This would drastically skew statistically significant results.
- Third, this study does not specify methods and materials for T-RFLP of the 16S rRNA genes. In this regard, the index used to measure the microbial diversity is lacking.
- Fourth, it is not clear what method the researchers used to confirm that an accurate dose per labeled directions was given each time during the study. Simply weighing a bottle before dispensing and at completion is only an estimate and would not take into account proper suspension in an oil matrix should the child`s guardian have failed to sufficiently shake the solution, for example.
- Fifth, this study doesn`t specify the method to confirm the colonization of L. reuteri. It could be that their method of detection (not stated) was sensitive or it could indicate that there was poor adherence to the protocol by the parents for administering the probiotic as required.
- And finally, it isn`t clear whether researchers completed a pre and post analysis of the total probiotic bacteria in the drops given to the infants to ensure dosage.
It is not uncommon to find conflicting research in any field of study. This is why IPA supports independent researchers to test the proof of concept and efficacy of probiotics in any field, including colic. IPA applauds the work and effort of Sung, et al. and looks forward to continuous research in the area. Undoubtedly, additional clinical trials and interventions should continue to be performed to validate and ascertain the effects of probiotics and infantile colic.