An article published in late September by researchers at the Massachusetts Institute of Technology in the Journal of Probiotics and Health shows the importance of the maternal microbiome in the gender and survival of their offspring. Eight-week-old female mice were fed a control diet, a diet representing human fast food consumption, or a diet in which their drinking water was supplemented by the probiotic Lactobacillus reuteri, a bacterium that has been implicated in female oxytocin regulation. Another group of oxytocin-deficient female mice were fed a control diet, or a control diet supplemented by the probiotic. The mice were mated and offspring were observed for three generations.

The researchers concluded that offspring survival increased when mice were given L. reuteri in their diets, and survival decreased significantly with the consumption of a ‘fast food’ diet when compared to the control group. They also concluded that probiotic-treated wild type mothers had an increase in number of female offspring. However, no increase in female progeny was observed in the probiotic treated mice that were oxytocin deficient, suggesting that probiotic exposure affects levels of oxytocin in females, and this leads to the increase in female offspring.

This research is significant in that it links probiotic intake of mothers to survival of offspring and sex of offspring. It also shows a possible relationship between the microbiome and the hormone oxytocin, which is linked to reproductive and social behavior in female mammals.