I will scream this from the rooftops until people hear me on this one. Taking probiotics is probably a dead end for any kind of lasting treatment. I used to have terrible gut issues (IBS-D) and I do not have them anymore. Probiotics never helped, but B2 and changing my fatty acids did. This new study shows why. It clearly points to changes in PUFA status effecting gut microbes. So if you take probiotics, but eat a lot of omega 6, in my opinion you are wasting your money. http://www.sciencedaily.com/releases/2015/08/150827130139.htm Fish oil-diet benefits may be mediated by gut microbes Diets rich in fish oil versus diets rich in lard (e.g., bacon) produce very different bacteria in the guts of mice, reports a new study. The researchers transferred these microbes into other mice to see how they affected health. The results suggest that gut bacteria share some of the responsibility for the beneficial effects of fish oil and the harmful effects of lard.