LeanBiome The proprietary blend of premium ingredients has been meticulously formulated to support the body's natural processes while providing essential nutrients that are often lacking in modern diets. LeanBiome is a dietary supplement formulated as a capsule that focuses on the gut microbiome as the root cause of stubborn weight gain and belly fat, claiming to re-balance the gut environment by populating it with nine clinically-researched lean bacteria strains, such as Lactobacillus gasseri and Lactobacillus rhamnosus; the product's mechanism of action is designed to restore a healthy gut, which proponents claim supports appetite control, reduces unhealthy cravings, and fires up a sluggish metabolism to promote more efficient fat burning.