As part of the Reproducibility Project: Cancer Biology, this report describes the attempt to replicate critical experiments from the paper “Intestinal Inflammation Targets Cancer-Inducing Activity of the Microbiota” (Arthur et al., 2012). In agreement with the original study, the authors did not observe any changes on bacterial growth or colonization when the polyketide synthase (pks) genotoxic island was deleted from E. coli NC101.
However, for the in vivo studies using IL-10-deficient mice, the replication attempt showed increased mortality and severity of inflammation compared to the original study. This difference was likely due to an insufficient description of methodology in the original study. Additionally, early death occurred during azoxymethane treatment with higher mortality observed in NC101D pks mono-associated mice compared to NC101.
As a consequence, the data obtained were unable to address whether, under the conditions of the original study, NC101 and NC101D pks differ in inflammation, invasion, and neoplasia. Thus, this replication attempt highlights the need to clearly describe experimental methods to ensure accurate reproduction of experimental studies.