Guinness is changing its beer recipe for the first time in 256 years. But, before you freak out, it's actually probably for the best. Because as it turns out, we've been unknowingly drinking traces of fish bladder every time we order a pint of Guinness. Yep, fish guts. According to the Huffington Post, Guinness uses a special gelatin called isinglass to get rid of the yeast in its beer. And isinglass is made with fish bladders. The gelatin is eventually removed from the Guinness that we end up imbibing, however, trace amounts of fish still remain. Guinness is currently looking for an alternative to the isinglass, that way vegans and vegetarians can also consume the beverage. We had no clue that all this time we were getting a little more protein than we bargained for every time we sip a frothy pint.