Is nulo cat food reliable? Can it really help cats regulate their intestines and stomach?

Give a reliable answer, of course. Our cat is picky about food and has weak gastrointestinal function. My mother went to a pet store to buy cat food, and the boss recommended nulo's gold medal series, saying that nulo's cat food contains probiotics, which is good for the stomach. I thought my mother bought it blindly, and then I checked it myself? I found that the boss didn't lie. Nulo has a good reputation, and probiotics are still patented. In the process of changing food, I can feel my appetite getting better and my stool is not as big as before. I feel that the gastrointestinal function is really improving. I bought all the flavors of squatting activities recently, and then I changed to eat them. I'm not tired of so many flavors.