What is the difference between probiotics & prebiotics? probiotics are the “good bacteria.” Probiotics are what you want to implement into your diet on a daily basis if you are struggling with gut issues. Allergies, autoimmune diseases, asthma, and so much more are caused from unbalanced gut bacteria. prebiotics are the fiber foods which feed bacteria. Prebiotics are dietary fibers that are food for the good bacteria in your gut. All helping to boost the microbiome balance.