02/18/2013 01:17 EST | Updated 04/20/2013 05:12 EDT

Germs May Hold the Key to Infant Health

2012-05-28-GermGuyBanner.jpg Should pregnant women have a natural or caesarean birth and afterwards, should they breastfeed or use formula? The debate has been at a standstill for quite some time yet thanks to a relatively new branch of science, there may be a means to resolve the disquiet.

In the weeks following Valentine's Day, many couples will head back to their favorite pharmacy although they will walk past the chocolate and flower aisles and head straight to the early pregnancy test kits. For those who are positive -- and who actually want to become pregnant -- the news is life-changing and opens up a future that can be exhilarating. However, for many of these women, the news may also inadvertently enter them into a two-pronged debate that has been raging for decades.

Should they have a natural or caesarean birth and afterwards, should they breastfeed or use formula?

The scientific literature has focused on this debate though the results have been less than helpful. There has been a recorded reduction in the rate of natural births over the years as well as a drop in breastfeeding. In turn, numerous attempts to increase those numbers have been shared ranging from objective reviews to thinly disguised promotions. Yet none of these studies or a plethora of others have conclusively shown a benefit of one over the other. In fact, some studies have shown that caesarean may actually be beneficial for mothers and that formula with an appropriate formula with micronutrients may indeed help the infant stay healthy.

The debate has been at a standstill for quite some time yet thanks to a relatively new branch of science, there may be a means to resolve the disquiet. Unlike traditional routes such as psychological, physiological and social research, this one focuses not on the human being but rather the beings that live inside it.

Germs and more importantly, their diversity.

The body is comprised of a highly diverse population of bacteria and that in healthy individuals and thanks to the Human Microbiome Project we now know that this variety doesn't shift significantly. But in August of this past year, a study from a group based out of Cornell University put that stability to the test in infants as well as pregnant women. They discovered that in women, during the third trimester and lasting until shortly after pregnancy, this diversity is radically altered. The changes were presumably due to a number of physiological changes that occur during that time. But the development of this diverse populace, which is shared with the infant, may have a secondary purpose.

The introduction of such a variety of bacteria offers the burgeoning immune system of the infant to decide which germs are friendly and which are foes. This form of immunological training may then help to prevent problems in the future, including overreactions such as asthma and other chronic diseases.

What was perhaps most interesting was that in healthy children, by the time they reached four years of age, they had the same diversity as their mothers before pregnancy. This cyclical nature of microbiome diversity suggested that for best health, infants needed to be exposed to a large variety of germs.

Last week, a new study from a collaboration of Canadian scientists led by Dr. Anita Kozyrskyj at the University of Alberta has offered more evidence to the debate. However, based on their findings, the debate may finally be settled, at least in Canada.

The team examined the gut microbiota of 24 infants at four months of age in order to perform a look-see into the state of the growing infant. Once the bacterial strains were identified, the researchers went back to determine if there were any differences between mode of delivery and infant diet.

In terms of mode of delivery, the results were not altogether surprising. There was a noticeable albeit small increase in microbial diversity in those born vaginally compared to elective caesarean sections. In both forms of delivery, the majority of bacteria found were no different than what might be found in the normal healthy gut including such well-known names as Bifidobacteria and Streptococcus.

The only real difference between the two was found in the levels of the sometimes pathogenic bacteria, E. coli, Shigella and Bacteroides. Unlike what might be expected, these levels were all higher in infants delivered vaginally. While this might suggest that vaginal birth presents more risk, there was no indication that these strains were at all pathogenic and instead were part of the normal microbial flora of the mother.

The differences were even less prominent when the results were compared to feeding habits. In almost all cases, there was little to no difference between breastfeeding and the use of formula. In fact, there was less diversity in infants who were exclusively breastfed. The only marked difference was the reduction of the presence of the pathogen C. difficile in breastfed children. This result, however, would be expected as the bacterium is primarily an environmental pathogen and would not be expected to be found on the breast or in breast milk.

In the entire context of both infant delivery and feeding, the study revealed little advantage to any means chosen. In fact, the results suggest that in the developed world, where proper medical care and formula of a high nutritional value exist, there really is no debate to be had. The medical community has essentially learned how to mimic the natural state and ensure that the child will grow up healthy whether the route followed is traditional or modern.

So, does this signal an end to the debate? Not likely.

While this study may offer some resolution to the debate here in Canada, the reality is that the majority of the world does not enjoy the advanced medical and nutritional care offered here. There is little doubt that in areas where women and children's healthcare is poor, there is a risk of improper colonization with harmful pathogens during non-vaginal delivery and also malnutrition in absence of breastfeeding or safe alternatives. In these environments, there should be little doubt that the ways of the ancients should be the preferred choice today.