Bifidobacteria Bifidus are a genus of probiotic bacteria naturally residing in the human gut, particularly in the colon, where they contribute to microbial balance. These anaerobic bacteria participate in carbohydrate fermentation, producing short-chain fatty acids that support gut ecology. They also interact with immune pathways and enzymatic activity linked to digestion and homeostasis. Their presence influences gut microbiota composition, enhancing metabolic interactions and stability. As key constituents of intestinal flora, bifidobacteria contribute to gastrointestinal function and microbial resilience.