Probiotic supplements! Probiotics and prebiotics can be added to your pet's diet to boost your dog's immune system, aid in digestion, and produce nutrients and vitamins. Keep reading to find out how a pre-and probiotic supplement can help your pet. Using Probiotics for Dogs. Probiotics refer to friendly and beneficial gut microbiomes. Probiotics for dogs can help restore balance to gut bacteria and, as a result, reduce a variety of gastrointestinal problems.