research vs the news – are c/s and formula babies really doomed?

You might have seen a study in the news that looked at the gut contents of babies that were born by caesarean section vs vaginally and that were breastfed or formula fed.  For those that misssed it, here are some links:

CBC article

Globe and Mail

Winnepeg free press

Toronto Star

I guess it was a slow news day…or newspapers know they will get a lot of traffic and readers whenever they run a story that has the potential to throw some napalm on the ever-smouldering mommy-wars…or maybe the study was Canadian and promoting research is part of Canada’s “action plan,” whatever that is.  Anyway, this study got a lot of press and most of it was pretty misleading…along the lines of:

“Ladies, your c-section babies are doomed!  Doomed to a life of inadequate gut flora and since gut flora is the new cool thing to blame for all kinds of chronic ailments your babies are going to contribute to Canada’s health crisis and the destruction of all we hold dear.  Oh, and if you thought breastfeeding them was protective, think again…oh and those of you that had a c-section and formula fed…forget it.  You are doubly doomed and your infants’ stool is full of c difficile…you know that bacteria the kills people in the hospital?”

Okay, maybe it wasn’t quite that bad.  The study was published in the canadian medical association journal and can be found here (it’s open access so you can read the entire thing if you are inclined). 

In a nutshell the authors took 24 infants between 3 and 4 months of age and ran their stool through a nifty DNA sequencer to characterize the “diversity” and “richness” of their gut flora.  They found some differences between infants that were delivered by c-section and some differences based on feeding type.

That’s it.

This study does not provide any link at all between delivery type, infant feeding type, and any future health risks.  The authors do hypothesize a mechanism, but, really, we can all hypothesize whatever we want, whenever we want.  The acid test is, “does the evidence support this hypothesis?”  And the answer is, “not the evidence we have right now.”

This study certainly wasn’t sufficient, IMHO, to justify the alarmist and sensationalist news coverage, including quotes from one of the authors.  It is all speculation at this point.

Among the thing we don’t know:

When does infant gut flora stabilize?  Sometime after the introduction of solid food, dirt, dog hair and whatever else babe picks up off the ground to ingest, surely…but when?

Does the unstable make up in early infancy make a difference to gut dysbiosis?

Does early life dysbiosis cause disease later?  Or does your flora need to be out of whack more closely to when you develop symptoms?

If the infants are perfectly healthy, which they are, how did we determine if the flora in the vaginally birthed infant is somehow superior to that of the surgically birthed infants?  Assumption?  Speculation?

Should this study be used to promote vaginal birth and breastfeeding?


Why did the authors feel the need to specifically mention women chosing c-section delivery in their introduction?  Seriously, maternal request is 2% or less of total c-sections.  Was it germaine to situating their study within the current body of literature?  No.  Why didn’t they mention inductions in primips?  They have a much higher contriubtion to the c-section rate.  Or bemoan the low VBAC rate?  Was this political?  Or does a c-section by request magically make your baby’s gut flora even worse? 

The news people could equally have picked up on the story that your gut flora is richer and more diverse if you were born after a failed trial of labour.  Maybe it’s worth inducing all moms in order to promote emergency c-sections.  That’s as supported by the data in this study as any other hypothesis you might want to come up with.

Mine?  I think we should investigate the utility of fecal transplants from exclusively breastfed vaginally birthed infants for the prevention of future autoimmune disease.  Oh…and maybe the treatment of it too!  Moms sell boob milk, I am imagining a market for baby poop – liquid gold people, liquid gold (or mustard, if you want to get pissy about it.)

Much love, TAM.


  1. Rebecca · · Reply

    TAM, I could have sworn I just read a study that showed emergency deliveries, broadly (including c-sections, ventouse and forceps deliveries), were the culprit. Culprit in what, you ask? Well, if I could remember that, I’d be citing the study here instead of vaguely alluding to it. It was either asthma rates, or something related to gut flora. Maybe in the morning I’ll be more coherent. 🙂

  2. supermouse · · Reply

    Yes, the first thing I thought of when I saw that was: “Differences? Who cares? It doesn’t say or show that one type of gut flora is better than another.”
    I imagine gut flora would vary widely among regions…someone do a study that includes thousands of infants from all over the world, and determine if the gut flora is different. Possible confounding factors could be formula fed v breast fed, so the babies could be divided into two groups right there. Then parental/regional diet. Then check the same babies over time, at 3mos, 6mos, 1yr or something like that. Also, look at parents and see how infant flora compares to adult. From there, perhaps a new hypothesis could be drawn as to the long-term effects, if any, from having a particular set/type of gut flora.

  3. Thank-you for this take on this sensationalized piece of baby poo. It seems like if there’s an opportunity to demonize csections by choice or the women who choose them it is seized upon…

    1. Mentioning maternal request c-section in that paper was gratuitous in the extreme – a cheap attempt to garner press from flaming a controversy that had absolutely no meaningful connection to the science presented.

  4. alinakaren · · Reply

    I had unmedicated vaginal births and bf each of my sons for two years. They are not perfect, and suffered from ear infections enough to warrant tubes, and the eldest developed a benign tumor and lost hearing in one ear. No guarantees one way or the other, so please leave parents alone to choose what is right for each child!!!

  5. Rebecca · · Reply

    I’m back, at last.

    In this study, they compared siblings to reduce confounders, and separated out the effect of elective vs emergency c-sections. They found that elective c-section was *not* associated with an increase in the rates of asthma; only emergency c-section was.

    And this study shows that vacuum extraction is associated with a higher risk of asthma. Combined with the above, the indications may be that any increased asthma risk may be caused by the same conditions that led to the emergency c-section or vacuum delivery, and not by the mode of delivery itself.

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