By the year 2039, the scientists — who hail from Cambridge University –think that their so-called E. Chromi could be mixed in with a special probiotic yogurt, which when eaten, would colonize the bowels and release pigments in the presence of diseases such as cancer, stomach ulcers and salmonella. If your poo was green, for example, you might have an ulcer, or if it turned orange, you may want to get tested for colon cancer.