The Publisher and Editor are issuing an Expression of Concern on the article titled “Effects of Daily Consumption of Synbiotic Bread on Insulin Metabolism and Serum High-Sensitivity C-Reactive Protein among Diabetic Patients: A Double-Blind, Randomized, Controlled Clinical Trial” [Ann Nutr Metab. 2014;65(1):34–41, DOI: 10.1159/000365153] by Maryam Tajadadi-Ebrahimi, Fereashteh Bahmani, Hossein Shakeri, Haleh Hadaegh, Mohammad Hijijafari, Fatemeh Abedi, and Zatollah Asemi.

Following publication, concerns were raised regarding the article by Tajadadi-Ebrahimi et al. regarding discrepancies in the sample size reporting between articles based on this study, date of the start of the trial relative to the date of ethics approval and date of trial registration, overlap with other articles with the same trial registration number without acknowledgement, inconsistencies in the application of exclusion criteria, possible undeclared conflict of interest with the study material provider and concerns about some of the data presented.

The concerns have been investigated by the National Committee for Ethics in Biomedical Research at the Iranian Ministry of Health and Medical Education. As our investigation is ongoing, we are issuing an Expression of Concern and readers should thus interpret the data presented in the article with caution. Appropriate editorial action will be taken once the investigation is concluded.