Caesareans, breastfeeding and gut bacteria

Once again the media have gone rather mad about a research paper without assessing the details of paper itself in an attempt to deliver sensational headlines about caesarean birth.

This paper actually describes gut bacteria in 24 infants at 4months of age but the media have rehashed old concerns about links with asthma.

It is entirely possible to make statements about the presence of the various bacteria from reliable tests conducted on the infants fecal matter and the paper should really have stopped there. However, it goes on to suggest links between caesarean birth and lower levels of breastfeeding and an increased likelihood of developing health problems in the long term (as a result of a lack of exposure to certain gut bacteria due to not having passed through the birth canal).

Aside from the media’s poor attempts at reporting on a very small, inconclusive study, I  take issue with the research paper itself:

  • No mention, or assessment of any environmental factors which can also easily influence gut bacteria level, other than use of antibiotics, (it looks purely at birthmode and breastfeeding patterns)
  • Only one assessment of gut bacteria levels are taken (at 4 months of age – no follow up to assess changes due to on-going development and exposure to new environmental factors – yet it is widely acknowledged that “gut profiles vary widely in the first year of life.”)
  • Sample size is laughable small (the total number of babies assessed – 24, of these only 6 were actually caesarean births) “A study of this size is too small to reliably detect any differences between natural and caesarean deliveries, and formula and breastfed babies, and even less so to detect any differences according to type of caesarean delivery (emergency vs. elective) or brand of infant formula, for example”

What is particularly disappointing is that the researchers feel comfortable making vague statements along the following lines “It could be that C-section physically prevents newborns from acquiring microbes they would during vaginal births” (which quite clearly shows even they cannot say their study provides conclusive evidence let alone how these bacteria levels relate to later health issues) and yet they are happy to produce a paper suggesting there is a link with caesarean birth specifically. Not only this but they take no account of the impact their statements may have on mothers who ‘need’ a caesarean to avoid serious outcomes. Nor dothey offer any information about how women can redress the bacteria imbalance. In otherwords they scare without offering any hint of a solution.

The NHS have been very quick to denounce the media’s scarmongering and suggest extreme caution when attempting to draw any conclusions from such a small study.

“The study does not provide any evidence that the mode of delivery or feeding pattern was the cause of the bacterial levels measured. Neither does the study provide any evidence that being born by caesarean delivery leads to developing asthma later on in life”

They go on…

“The researchers say that the development of bacteria in the gut in the early part of a person’s life is poorly understood. However, the design of this study means that it arguably adds little to that understanding. It only examined the gut bacteria of an extremely small sample of babies at one point in their life and can tell us little else about the causes of these bacterial levels, or how they related to longer-term health outcomes.”

And there is more…

“Neither does the study provide any evidence that being born by caesarean delivery leads to developing asthma later on in life.”

As for the media’s poor attempts at interpreting the paper, they have chosen to re-hash claims suggesting there are links with childhood asthma. This despite the majority of studies investigating such a link having been repeatedly shown to be inconclusive often omitting significant environmental factors, such as the presence of parental smoking.

Actually don’t get me started on the media…