Although the human GI system is generally very similar, factors such as diet, race, age, antibiotic use, stress, environmental factors, and exercise can influence gut health. Gender is one of the important variables affecting the gut microbiota, and researchers are just beginning to understand why. Additionally, several of today's more sophisticated probiotic products will offer advanced blends and targeted formulas that contain specific strains or other active ingredients that provide unique health benefits for women or men. While there are many probiotic products that are not gender-specific, the added benefits these Men's or Women's formulas provide are certainly worth considering.