A recent article in Nature Communications demonstrated that a connection between changes to the gut microbiome which occur due to diet are different for different genders. These experiments were performed first on fish, then with humans. The gist of the experiments was that when new diets are introduced to humans, each individual's microbiome responds differently depending on gender.

This has interesting implications to the community moving forward. First, it demonstrates a direct link between genetics (gender) and microbiome populations, a link that, while self-evident, has been difficult to experimentally prove. Second, the authors suggest that links such as this may be the cause of certain diseases that are gender biased, such as IBD that appears to affect women more than men. On a final note, it highlights the need for future research to control for gender, and future microbiome therapeutics and probiotics to consider gender as important variable.

Why does the microbiome adjust differently for men and women when a new diet is introduced? That is currently unknown, but the authors mention gender-specific hormones and gender-specific immune functions as possible causes.