When I review the probiotic literature, I have a distinct bias. Taking precedent for me over all studies is a well-controlled and well-reported human study. As cool as all the studies on probiotic mechanisms or impact on microbiota are, in the end what matters to me is if there is convincing evidence that a probiotic can impact health. Next, I look at the endpoints for the study – what did the researchers measure? If the endpoints for the study are meaningful ones, then I pay close attention to the study. Endpoints such as prevention of illness, alleviation of symptoms and improved quality of life are especially compelling.
The medical community understands the importance of meaningful endpoints. An initiative started almost 2 decades ago in medicine is the concept of Patient-Oriented Evidence that Matters, or POEM. POEMs have to address a question that doctors encounter, measure outcomes that doctors and their patients care about (symptoms, morbidity, quality of life, and mortality) and have the potential to change the way doctors practice. For example, a study that measures joint pain or mobility is of greater interest than one that measures levels of joint inflammation.
Bringing this back to probiotics, I remember being impressed a few years ago by the primary endpoint of a randomized, controlled trial (RCT) by a researcher in Italy, Savino et al. 2007: infant crying time. What parent doesn’t appreciate this as an extremely important endpoint? A follow up RCT was published in 2010 by this same group. Both these studies showed that Lactobacillus reuteri reduced infant crying time, as did an RCT from Poland. A study in progress in Australia is further testing L. reuteri on infants with colic: Probiotics to improve outcomes of colic in the community: Protocol for the Baby Biotics randomised controlled trial.
This month in the Journal of Pediatrics, an RCT was published that showed the impact of probiotics on crying and fussing in preterm infants – although this time the probiotic tested was L. rhamnosus GG. This study, conducted in Finland, was a 3-arm study and compared L. rhamnosus GG, a prebiotic mixture of galacto-oligosaccharide and polydextrose, or a placebo. Pärtty et al. (2013) randomized 94 preterm infants (gestational age 32-36 weeks and birth weight >1500 g) to one of the 3 groups. Infant “fussiness” (extent of crying and irritability) was measured over the first 2 months of life. Significantly fewer infants in both the probiotic (19%) and prebiotic (19%) groups compared to the placebo (47%) group were classified as excessive criers. Interestingly, a higher percentage of excessive criers were vaginally delivered (81% vs. 63%) although this difference did not reach significance (P=0.07). Exclusively breast fed infants over the 2 month evaluation period tended to be less likely to be excessive criers (P=0.09).
These studies suggest that at least certain strains of probiotics can be effective in reducing crying time in fussy babies. The medical community recognized this, as seen in a 2011 Priority Update from the Research Literature (PURL) on probiotics and colic.
Koonce T, Mounsey A, Rowland K. Colicky baby? Here’s a surprising remedy. J Fam Pract. 2011 January; 60(1): 34–36.
Pärtty A, Luoto R, Kalliomäki M, Salminen S, Isolauri E. Effects of Early Prebiotic and Probiotic Supplementation on Development of Gut Microbiota and Fussing and Crying in Preterm Infants: A Randomized, Double-Blind, Placebo-Controlled Trial. J Pediatr. 2013 Jul 31. doi:pii: S0022-3476(13)00584-2. 10.1016/j.jpeds.2013.05.035.
Savino F, Cordisco L, Tarasco V, et al. Lactobacillus reuteri DSM 17938 in infantile colic: a randomized, double-blind, placebo-controlled trial. Pediatrics. 2010;126:e526–e533.
Savino F, Pelle E, Palumeri E, Oggero R, et al. Lactobacillus reuteri (American type culture collection strain 55 730) versus simethicone in the treatment of infantile colic: a prospective randomized study. Pediatrics. 2007;119:e124–e130.
Sung V, Hiscock H, Tang M, Mensah FK, Heine RG, Stock A, York E, Barr RG, Wake M. Probiotics to improve outcomes of colic in the community: Protocol for the Baby Biotics randomised controlled trial. BMC Pediatr. 2012; 12: 135.
Szajewska H, Gyrczuk E, Horvath A. Lactobacillus reuteri DSM 17938 for the management of infantile colic in breastfed infants: a randomized, double-blind, placebo-controlled trial. J Pediatr 2013;162:257-62.