OCLN and escherichia coli infection: In addition, the protein results of Occludin showed that the tight junction protein recovered with the FMT of 4-PBA (Figure 5E) and the immunofluorescence results of ZO-1 and Occludin proteins on colon tissue also demonstrated that the FMT of 4-PBA could prevent the destruction of intercellular connections caused by E. coli infection (Figure 5F).