Mixed Results Remixed For Probiotic Use In Colic
We've cured colic. We haven't cured colic. Wait, we have cured colic. Say what now?
If you have been trying to follow the data on probiotics as a cure for colic I am sure that you, like me are pretty well confused. Just recently many news stories hit the press about the "latest" study on probiotics for colic. I say latest in quotes because it was nothing more than a re-analysis of existing studies that had mixed results. We'll talk about what's at stake, for whom and what the data really looks like when you dig deep.
What's At Stake
Gerber's Soothe Probiotics have been hitting the world by storm. Heavy marketing rotation both online and offline have drilled into our heads that the super expensive probiotics can solve many problems including colic. Behind the Gerber Soothe Probiotics is a company called BioGaia that has licensed their strain of probiotics to Gerber, and so for all intents and purposes when you are talking probiotics for colic you are talking Gerber AND BioGaia.
Digging Into The Data
So let's start with a quick history. A first study was conducted in Italy and funded by BioGaia. It included 46 subjects who were breast-fed and showed statistically significant improvement in total crying time only at day 21 (last time point measured in the study). Reduction in crying time of at least 50% did show a benefit for the probiotics but overall the studies results were called into questions because the methods used for annotating crying times were only completed at the end of the day, leading to perceptive bias and inaccuracies.
A second study, conducted in Poland included 80 breast-fed subjects also had mixed albeit somewhat more positive results. Again an end-of-day diary used in the study may have led to inaccurate data but it is hard to make any conclusions either way. The Medical University of Warsaw where the study was conducted had received a donation from BioGaia.
A third study was conducted in Australia and included 167 breast-fed and formula fed subjects. In this study the investigators used a real-time diary so as to maintain more accurate records. They found no benefit for probiotics over placebo related to crying/colic, even in a subgroup analysis of breast-fed subjects only. The team doing the study received no funds from BioGaia but had two members that had unrelated affiliations with Nestle's Advisory Board (owner of Gerber). In their discussion the authors cited, among others the following reasons why their results were so different than previous studies:
- This sample size was much larger and might better capture the true effect of the intervention, in this case the probiotics
- This trial was the only trial to date to use a validated real-time diary to record crying
- It is possible that the gut bacteria of subjects in Australia might be different and thus unaffected by probiotics
A fourth small study conducted in Canada with 52 breast-fed subjects did show promising results at all time points in terms of crying time reduction. This study did use a more accurate crying diary and did not appear to have any financial conflicts.
So what to believe? A very large study (almost as large as all other studies combined) that says probiotics don't work for colic? A few small studies with mixed results that utilize inaccurate crying diaries and include financial conflicts? Or do we believe a single small study with the accurate diary and no conflicts that showed success for probiotics in breast-fed subjects. At this point its hard to decide but thanks to money from good folks at BioGaia and Nestle we now have a "meta-analysis" combining data from all of these studies together in an effort to button up the package.
The meta-analysis concluded that probiotics do indeed work for colic in exclusively breast-fed infants but not in formula-fed infants. Unfortunately there is still the issue of some data being biased by the end-of-day diaries and a second issue related to financial conflicts: A number of the authors of this meta-analysis are paid consulting fees by either BioGaia or Nestle.
Bottom line for me is that probiotics may or may not work but what I don't see yet is any scientific evidence that supports the mechanism of action - how they think probiotics help treat colic. The biology is not well-proven yet and at least for me, spending $22 or more for less than an ounce of probiotics without strong evidence may make this a last resort choice, not a first.