So, I used to study this a little, in particular how cancer treatment can mess with taste, smell, entire digestive system. So yes there are things that can happen (chemo, radiation, antibiotics, certain illnesses) that can affect your biome. And yes even if you take probiotics, but don't have a diet that "feeds" the bacteria it won't last. A fecal transplant does last longer (currently only done for c. Diff infections, but I wouldn't be surprised if its prescribed for crohns disease in the future) So if your biome is wiped out or otherwise impoverished (cesarean section, being bottle-fed, not being allowed to play in the dirt. Western diet) sure take the probiotics but Also basically eating a lot more foods that are essentially high in fiber (vegetables of all kinds, mushrooms, fruit with peels, legumes and seeds etc, fermented foods). I'm really glad to hear about the red wine. I love red wine. Anyways while you shouldn't eat things you are allergic to or give you problems, in general the digestive system works as a use it or lose it system. If you stop eating meat, after awhile it will be harder to digest meat. Same with dairy. Same with going from low fiber to high fiber diet. But in general the digestive system can adapt.