Probiotics to tackle allergy in children?

I recently read an article in the Chicago Tribune “Probiotics for babies may not fight allergies later”¹.  With so many articles on parenting floating around the internet my assumption was this article would be debunking some new-fangled parenting technique like attachment parenting or elimination communication (google it).  Interestingly, it was more of a follow up of an article I read a couple years ago on birth by caesarian section  (C-section)  resulting in a greater occurrence of allergic rhinitis and allergy sensitization than in children of vaginal birth.  The gut of a fetus is sterile containing no bacteria; the bacterial colonization of the infant’s gut begins to occur immediately with childbirth.  It is thought that children born via C-section are not exposed to maternal vaginal/fecal flora and, therefore, have different bacterial profiles resulting in greater occurrence of allergy.  

This is where probiotics step in, as a healthy gut flora aids the immune system, probiotics would aid in developing the healthy gut.  Adults can’t get enough of their probiotics, as evidenced at the yogurt aisle, so investigating the effect of probiotics in children seemed a natural step.  The main problem with probiotics, for both adults and children, appears to be probiotics come as a mix of a bunch of different strains of bacteria.  While it’s known there are beneficial bacteria that aid in digestion and synthesizing vitamins, and protect against pathogens, which probiotics may be helpful is still to be determined.   Studies, like the one in the Chicago Tribune, investigating the impact of probiotics in children have resulted in a jumble of results.  These studies show small benefits in probiotic protection against allergy, with one study showing only positive results in children born via c-section³.  Are these small effects a result of the lack of data on probiotics and which strains researchers should be looking at?  I’m sure, like all things in biology, we have something that is multifactorial and not merely a result of a C-section or not, probiotic or not. As evidence for the amount of layers involved in investigating this issue research is coming out on maternal probiotic supplementation's impact on placental and fetal immune physiology⁴, as well as breast milk composition.   

For now preventing allergy is just another thing for parents to worry about.  I like to think I will still have my children build up their immunity much like I did, with the calling of poison control every other day because of the odd plant, flower, or pile of dirt I put in my mouth (who knows what bacteria were on that!), but maybe I’ll try to toss in vaginal child-birth as well. 

 

1. http://articles.chicagotribune.com/2012-09-28/lifestyle/sns-rt-us-probiotic-for-babiesbre88r13q-20120928_1_probiotics-fight-allergies-bacteria
2. Jensen, M. et al Early probiotic supplementation for allergy prevention: Long term outcomes.  The Journal of Allergy and Clinical Immunology.  (2012).
3. Kuitunen, M. et al. Probiotics prevent IgE-associated allergy until age 5 years in cesarean deblivered children but not total cohort.  The Journal of Allergy and Clinical Immunology.  (2009). 
4.  Rautava, S. et al. Probioticsmodulate host-microbe interaction in the placenta and fetal gut: a randomized, double-blind, placebo-controlled trial. Neonatology (2012)