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Do C-Sections Increase Obesity Risk By Changing The Bacteriome?



sharma-obesity-gut-buts1The answer is, “perhaps” – but the possible mechanism linking the two may not be what many suspect (big babies).

Rather, the answer may lie in recent findings by Meghan Azad, from the University of Alberta (on behalf of the CHILD Study), published in CMAJ.

This study looked at the gut microbiota of healthy Canadian infants and found distinct differences in gut bugs at 4 months of age that were related both to the mode of delivery (vaginal vs. c-section) and feeding (breast milk vs. infant formula).

In an accompanying commentary, Se Jin Song (University of Colorado) reminds us that,

“Our microbiomes are complex and dynamic ecosystems, affected by interactions between our genetic predisposition, our behaviours and our environment”.

Not only do infants born by elective c-section have particularly low bacterial richness and diversity, but these changes appear to persist and can lead to lifelong issues including lasting changes in metabolism.

We now understand that,

“Early interactions with beneficial bacteria train the immune system of babies and are thus critical for healthy immunologic and metabolic programming. All mammals pass through the birth canal, which guarantees exposure the the mother’s vaginal bacteria first, before other environmental sources.”

A third article in the same issue of CMAJ by Paul Kudlow (Toronto) notes that our fear of bacteria and indiscriminate of antiseptics and antibiotics may have changed our natural bacteria in a manner that may be detrimental to our health.

As an example Kudlow cites studies that show that eradication of Helicobacter Pylori (a bug associated with stomach ulcers) has been associated with the development of obesity in animal studies, an effect possibly due to the known effect of this bug on the ghrelin secretion.

Given that over one in four babies are now delivered through C-sections in Canada, the increasingly apparent adverse health consequences of this practice for the baby may well be linked to changes in the bacterial flora of the infant.

Together with the many barriers to breastfeeding (noted in a fourth article in the same issue), these changes in early childhood may well play a role in determining the longterm risk for health problems including excessive weight gain.

AMS
Edmonton, Alberta

ResearchBlogging.orgAzad MB, Konya T, Maughan H, Guttman DS, Field CJ, Chari RS, Sears MR, Becker AB, Scott JA, Kozyrskyj AL, & CHILD Study Investigators (2013). Gut microbiota of healthy Canadian infants: profiles by mode of delivery and infant diet at 4 months. CMAJ : Canadian Medical Association journal = journal de l’Association medicale canadienne, 185 (5), 385-94 PMID: 23401405

Song SJ, Dominguez-Bello MG, & Knight R (2013). How delivery mode and feeding can shape the bacterial community in the infant gut. CMAJ : Canadian Medical Association journal = journal de l’Association medicale canadienne, 185 (5), 373-4 PMID: 23401408

Kudlow P (2013). Ten parts bacteria, one part human. CMAJ : Canadian Medical Association journal = journal de l’Association medicale canadienne, 185 (5), 377-8 PMID: 23422448

Chalmers B (2013). Breastfeeding unfriendly in Canada? CMAJ : Canadian Medical Association journal = journal de l’Association medicale canadienne, 185 (5), 375-6 PMID: 23439626

1 Comment

  1. “Not only do infants born by elective c-section have particularly low bacterial richness and diversity..”

    How come only infants born by ELECTIVE c-section are affected?

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