However, a meta-analysis found that among the dietary sources of protein, the risk of IBD increased only with increased amount of total meat intake, while the consumption of protein from dairy products was found to be protective against the IBD risk.27 Although we found no association between p-cresol sulfate with either gut permeability, CRP, host proteomic or FCP, a previous study described that p-cresol sulfate in excess was shown to be genotoxic for colonocytes28 and induced neutrophil oxidative burst activity in vitro.29 This evidence concerns the gene CRP and irritable bowel syndrome.