TPI1 and colon carcinoma: Removal of surface proteins such as GAPDH, elongation factor Tu (EF-Tu), and triosephosphate isomerase (TPI) by guanidine hydrochloride decreases the ability of lactobacilli to adhere to Caco-2 human colon carcinoma cells by 40%, suggesting that these surface proteins are important for bacterial adhesion to human intestinal cells [35].