**8. Conclusion**

The potential of probiotic *E. coli* is increasing over the years starting from maintaining the intestinal barrier in healthy individuals to the treatment of complex diseases such as colorectal cancer and inflammatory bowel disease. Since many commercial *E. coli* products were found to deviate by orders of magnitude in terms of claimed numbers, monitoring strain identity and numbers is imperative for exploiting their complete potential [73]. Distinct properties of *E. coli* probiotics coupled with the ease of developing strains with desired traits could greatly expand their applications.
