As I have noted before on this blog, our article showing the effects of the introduction of routine probiotics in our NICU has been published on-line. The Journal of Pediatrics decided to accompany it with an editorial by William Tarnow-Mordi and Roger Soll. As some of you may be aware, these 2 individuals previously wrote editorials with differing points of view about this issue, but they now both feel that routine probiotic supplementation should be instituted in at-risk infants.
I want to emphasize one point, the choice we have is not between administering exogenous organisms to high risk babies on the one hand, and leaving their intestines sterile on the other hand. The choice we have is between giving probiotics or allowing pathogen-based intestinal colonization with the flora of the NICU and then wrecking even that abnormal flora with antibiotics. Many of the criticisms of routine use of probiotics seem to assume that if we don’t give them then the gut stays in a pristine state, but we know that is not true, I am just trying to make colonization more normal.
However, there are still many unanswered questions about probiotics as prophylaxis against NEC, which need to be addressed even as we go forward:
1. It seems that lactobacilli and bifidobacteria, and various species within these genera, are effective, is there a species or mixture that is more effective than others?
2. A formulation specifically designed in single dose sachets for the NICU would be an improvement, and prevent risks of cross-contamination, is there a supplier who will produce such a formulation?
3. NEC still occurs, and can still be devastating. How can we further reduce the risks?
4. If we give antibiotics should we give booster doses of probiotics to counter the adverse effects? Indeed, is there a dose effect?
5. Should we start probiotics on day one, even if the baby is nil by mouth?
6. What are the long term effects of probiotic supplementation, compared to the usual pathogen based colonization of the bowel in unsupplemented preterm infants? The effects on asthma, colic, and the intestinal microbiome in the long term?
There is accumulating evidence about the importance of the microbiome in the adult, for example in the pathophysiology of obesity; earlier normalization of the microbiome in the very preterm infant may have effects on the development of the metabolic syndrome and other potential effects that would be really important to know, but will be extremely difficult to discover.