Many probiotic side effects are due to release and growth too early in the gut.
Personal experience that may or may not be helpful.<br /><br />If you have IBS, you may well have small intestinal bacterial overgrowth (SIBO).  In either case, taking a probiotic that is not enteric-coated or coated for release AFTER your small intestine may make your symptoms worse because you are recolonizing your small intestine (this includes Align, and most on the market).<br /><br />This product is enteric-coated, so should release after the small intestines to avoid putting bugs in the wrong place.  Read product info carefully to confirm enteric-coated, since they have other products.  They also have liquid versions that will dump the bugs in your small intestine.<br /><br />If you're microbiome is jacked up, BIG doses of any probiotic may mess you up.  I used the 12.5 billion version of this product (available elsewhere) to avoid over-doing it and it seemed OK for me, but maybe not you (see other review on backing off 25 billion).  Take home message is always start small.  Tread lightly.<br /><br />If you react, this may be rapid growth in your small intestine with bloating.<br /><br />If you react, you may be reacting to the prebiotics in the product, not the probiotic itself.  Avoid prebiotics initially if very sensitive.<br /><br />These bacteria may release d-lactate (brain fog).<br /><br />They may make you feel worse regardless particularly if you're sensitive to histamine in food, since these strains make histamine as a byproduct of normal metabolism.<br /><br />Bifidobacteria may not do this to the same degree, but these again should be engineered for release later in the gut (maybe Pearls Adult 50+ or others).  Pearls Adult 50+ contain only bifidobacteria similar to those in Align.  Align dumps in your small intestine.<br /><br />S. boulardii is a yeast and seems to be more tolerable (to me) that may help repair and get combat bad bacteria, but it will not of itself rebalance your bacteria.
Rating: 4 stars