ABSTRACT Colibactins are hybrid polyketide-nonribosomal peptides produced by Escherichia coli. Klebsiella pneumoniae. and other Enterobacteriaceae harboring the pks genomic island. These genotoxic metabolites are produced by pks-encoded peptide-polyketide synthases as inactive prodrugs called precolibactins. https://www.parisnaturalfoodes.shop/product-category/medi-c-plus-w-mg-berry/