Paper linking fecal transplants to obesity in rats retracted for faked data

A paper linking the fecal microbiome to obesity has been retracted after it became clear that one of the co-authors faked some of the data.

The 2014 paper in Diabetes — which found that rats given fecal transplants from obese mice were more likely to become obese themselves if given a particular diet — was pulled after after an institutional investigation found a co-author guilty of falsifying data underlying one figure and fabricating the data of two others.

Co-author Yassine Sakar — formerly based at the French National Institute of Agronomic Research (INRA) in Paris, France — was found responsible for the misconduct. But an official from the institution said that some responsibility must also be shared by the corresponding author Mihai Covosa, who has since resigned from the institution.

Here’s the retraction notice:

The lead and corresponding authors wish to retract the above-cited article as an institutional investigation has identified that coauthor Yassine Sakar falsified the data used to produce Fig. 4B, fabricated Fig. 5A, and fabricated the data used to produce Fig. S3(C). The authors regret these errors and apologize for any inconvenience to the readers of the journal.

The paper, “Replication of Obesity and Associated Signaling Pathways Through Transfer of Microbiota From Obese-Prone Rats,” has been cited 23 times, according to Thomson Reuters Web of Science.

Some have taken to social media to point out that one retraction from a field does not mean the whole discipline is false:

@XaiaX One paper was retracted bc the author made up data https://t.co/6VZfOLjbOg there are others that show same thing, not retracted

— Leigh Krietsch Boerner (@LeighJKBoerner) April 27, 2016

https://twitter.com/scicurious/status/725321522450075649

Sakar, who left INRA in February 2014, before the investigation began, has also notched a corrigendum for issues with figures of a 2014 paper, “Impact of high-fat feeding on basic helix–loop–helix transcription factors controlling enteroendocrine cell differentiation,” published in the International Journal of Obesity. The paper has been cited six times, and its correction has been cited once. It reads:

The original version of this article contained some errors in the figures. In Figure 1b, the x-axis labels ‘Visceral’ and ‘Epididymal’ were transposed. In Figure 2c, the second western blot image on the right was inverted and the images for Pax6, FOXA1 and CRIF1 were incorrectly represented. In Figure 2d, the blot image for FOXA2 was incorrectly represented. In Figure 3 a typographical error was introduced to the scale on the y-axis. In Figure 5b the blot images for PYY in the small intestine and colon and for secretin in the small intestine were incorrectly represented.

The corrected article appears in this issue and the html and online pdf versions have also been amended.

Olivier Le Gall, deputy director general for scientific affairs at INRA, told us the retraction notice does not address the fact the investigation at INRA concluded that some responsibility must also be taken on the part of the corresponding author. He noted:

Specifically, the investigation established the responsibilities of Dr. Sakar in compiling the data and preparing the figures, and of the senior author Dr. Covasa as corresponding author, and as “the guarantor of this work and, as such, [having had] full access to all the data in the study and tak[ing] responsibility for the integrity of the data and the accuracy of the data analysis” (quoting the “Authors contribution” section of the article).

Le Gall added:

When Drs Covasa and Sakar were given the opportunity to clarify the issues raised by the committee and that are eventually listed in the retraction notice, they failed to do so.

In Spring 2015, some of the co-authors of the article requested that the paper be retracted, but the last and corresponding author Mihai Covosa — who is now based at the Western University of Health Sciences in Pomona, California — did not agree to the retraction, according to Le Gall. The institution, therefore, set up a panel of both INRA and non-INRA experts in scientific integrity to examine the original data, and found “clear evidence of misconduct of several kinds,” explained Le Gall. He gave us an example:

…[E]veryone can easily notice that in Figure 5A, the top right corner of the “CVOP” panel overlaps slightly with the bottom left corner of the “Control” panel: as a matter of fact, a closer examination of the figure and the originals shows that all three panels of Fig. 5A were cropped from one same and single photograph field, while the legend states that they are supposed to belong to three different animals.

Next, said Le Gall, INRA asked Covasa to request the retraction of the article and ask the co-authors if they agreed. But, he noted:

Dr Covasa repeatedly refused to ask retraction in their names while the conclusions of the investigation committee were so clear, in September 2015 INRA as an institution asked Diabetes to retract the article.

Le Gall said the request for retraction from INRA copied in Covasa, and to their knowledge, he did not respond. The notice could have been written differently if Covasa had asked his co-authors to retract, Le Gall said, but instead it

does not fully render the corresponding author’s reiterated reluctance to request retraction of the paper.

In August 2015, Covasa voluntarily resigned from his faculty position as a senior scientist at INRA, Le Gall said:

That is, in a matter of days, around the time between the rendering of the committee’s conclusions to the head of INRA and INRA’s official command that he retracted the paper, but in his [resignation] letter Dr Covasa did not specifically mention the ongoing process.

Regarding the International Journal of Obesity corrigendum, Le Gall said:

…the current status of this article is that it was the subject of a corrigendum in November 2014 and, before this, an erratum in April 2014 (with the same DOI as the corrigendum) so the current online version is actually the 3rd one.

We’ve reached out the journal’s editor-in-chief, K. Sreekumaran Nair, a clinician at the Mayo Clinic in Rochester, Minnesota. Nair referred us to the American Diabetes Association (ADA) for a comment. Christian Kohler, staff liaison of the ADA’s panel on ethical scientific programs, said the panel reviewed and approved the retraction statement, but it was against the organization’s policy to comment publicly on details of such reviews.

We’ve also contacted Covasa for a comment, but could not find any contact details for Sakar. We’ll update the post with anything else we learn.

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