He asks: “With a more meat-based diet, my body is not expelling much waste. I’ve always noticed that for my dog who’s on a raw meat and veggie diet (that’s partially cooked mind you), and bathroom trips are not that much fun! I’ve tried quite a few little things including psyllium but not probiotics. What can Creator recommend?”

Humans were designed to be omnivores and that means being as much herbivores as carnivores. For most people, the key to a healthy digestive and excretory system is having a mix of dietary components that would include a significant amount of roughage—the fiber content in a variety of plant-based nutrients. Probiotics can be beneficial as well because it is often the case that an imbalance in the microbial makeup within the gut is the source of digestive complaints. Once again, local inflammation caused by pathogens in the lumen of the gut will cause trouble over time and even lead to systemic illness that can even be fatal. There is a large body of literature recommending probiotics to help manage the microflora to keep it within a healthy range. There is even positive clinical data for use of fecal transplants as a way of seeding the gut with more favorable microorganisms. That certainly does not need to be done universally but points to the fact that diet may promote an imbalance of microflora, thus the need for probiotics from time to time to correct things.