A cesarean section, or C-section, is major surgery that is done to deliver a baby through the abdomen. A doctor makes a 6- to 7-inch-long cut through the skin and muscle of the abdomen.

Cesarean section is one of the most commonly performed procedures for women, with almost a third of women in many developed countries experiencing cesarean section when they give birth.

Vaginal birth leads to changes in the development of offsprings’ microbiomes not seen among mice born via C-section, which researchers suspect might contribute to the weight differences. Ashley ...