More on breastfeeding…

As if you needed more reasons to choose breastfeeding, this just in from the journal Genome Biology:

Babies who breastfeed have a wider variety of bowel bacteria than those who are formula-fed. Why is this important? Because the bacteria in the newborn bowel (also known as the gut microbiota) help direct the development of the newborn’s immune system, among the many other beneficial functions they perform. A more diverse gut microbiota is associated with a healthier immune system.

We already know that babies born by cesarean section have a less-diverse gut microbiota than vaginally-born babies, and that following a c-section the newborn gut microbiota is often dominated by bacteria picked up from the hospital environment. Some of those hospital bacteria–clostridium difficile in particular–are associated with a number of nasty diseases in humans. From the looks of this study (and others), formula feeding may exacerbate the problem.

Nature intended for us to have a diverse gut microbiota, dominated by the types of bacteria picked up in the course of a vaginal birth and breastfeeding. We’re only now learning of the long-term health consequences of tinkering with that plan…

PS: In no way am I criticizing women who, for whatever reason, formula feed their babies. Exclusive breastfeeding isn’t always an easy thing to do in this day and age. But however it happens that a baby isn’t breastfed, the potential health impacts are the same.


Filed under Breastfeeding, Cesareans, Maternal-child health, Nutrition

2 responses to “More on breastfeeding…

  1. Once the gut microbiota are present, do they generally proliferate enough to be self-sustaining? (unless disrupted by a heavy course of antibiotics, etc.) Would these bacteria then still be present in greater diversity in adults who were breastfed?


    • Hi Erin,
      The “core” gut microbiota is pretty much set by age 2. There are three major factors that influence its composition: how you’re born, whether you’re breastfed, and what diet you’re weaned to. Antibiotic use is another factor, but in general it doesn’t seem to be as important as the other three.

      There haven’t yet been adequate long-term studies (i.e., all the way from birth to adulthood) to know whether the microbiota changes brought on by c-section birth, etc., are permanent, but at least one study followed kids from birth to seven years of age and found the differences to be lasting at least that long. They’re still following that group of children, so no doubt more information will follow.

      My concern is that the gut microbiota is definitely altered by cesarean birth and formula feeding during the critical initial period of immune system development. Promotion of vaginal birth and breastfeeding as public health measures can reduce the overall impact. And since there will always be cesarean births and women who can’t nurse, figuring out how best to promote a healthy newborn gut microbiota in all babies should be a focus of research. Discoveries in the next few years should be very interesting!

      Thanks for writing!


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