Based on an interview in an article on this site I bought the Schiff Digestive Advantage probiotic from Walmart. The Doctor in the article recommended highly the "Ganeden BC30" probiotic which is in the aforementioned product. Also, if you're serious about gut health definitely start with fermented foods(kimchi and sauerkraut). I haven't had any significant weight loss but that's not my intent and I never really had low energy so I cannot comment on that either. What I do have problems with is feeling and looking very bloated at times, gassy, and irregular bowel movements. I believe some of those symptoms are because of a gut bacteria imbalance as well as certain food intolerances(dairy for sure).