A mother’s gastric bypass affects her future children

Not long ago, I wrote a post explaining why gastric bypass is such an effective weight loss strategy. It seems that the procedure alters the microbial content of the subjects’ guts. Apparently, that’s not all that gets altered.

Frédéric Guénard of Laval University and his colleagues compared twenty-five kids who were born before their mothers underwent gastric bypass surgery (group 1) to twenty-five of their siblings born after the surgery (group 2). Genetic testing showed that close to 6000 genes were methylated differently between the two groups of children and that those differences were responsible for differences in gene expression. 

Let me repeat that: an action of a woman (undergoing bypass surgery) can alter gene expression in her children born years later.

This image shows a DNA molecule that is methylated on both strands on the center cytosine.
Created by Christoph Bock (Max Planck Institute for Informatics) 2/18/2006.

The changes in methylation between groups 1 and 2 were not random. The affected genes were predominantly ones involved in insulin sensitivity, metabolism and vascular disease. Sure enough, the kids in group 2 had less obesity and lower blood pressure, and were less prone to autoimmune or vascular disease or diabetes.

To be clear, the scientists haven’t established that gastric bypass surgery itself leads directly to having offspring with an altered methylation pattern. The difference could have resulted simply from changes in body composition or eating habits in the mother, or from the altered microbial environment around the womb. But one way or another, the gestational environment of kids does appear to affect them profoundly. 

If you’re a woman with your reproductive years ahead of you who didn’t already have enough to worry about, you’re welcome.


Guénard, F., Deshaies, Y., Cianflone, K., Kral, J., Marceau, P., & Vohl, M. (2013). Differential methylation in glucoregulatory genes of offspring born before vs. after maternal gastrointestinal bypass surgery Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.1216959110.