Gastroenterology & Hepatology

Publication Analysis 2005-2011
by Kathleen Gransalke, Labtimes 06/2014

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Intestinal mucosa of a 7.5 day old chick embryo. Photo: Poulomi Ray, Clemson University

Germany is unbeatable in terms of numbers of citations, articles and most-cited authors in our top 30. The hottest topic: Inflammatory Bowel Disease, in particular Crohn’s Disease.

What did you have for breakfast today? Cereals, toast or perhaps some fruit? Depending on when you read this article, your morning meal will have already passed your oesophagus and entered your stomach and intestines. Acids, enzymes and bacteria all help to set free all the nutrients the body needs, such as carbohydrates, proteins and fats. That is, if everything works as it is supposed to. But everyone who has been in far-away countries and has ended up spending hours on the loo, knows that the digestive system is a sensitive system. Montezuma sends his regards.

Lately, it seems that one doesn’t have to travel that far to suffer a similar experience. More and more people, especially in the West, are being diagnosed with disorders of the gastrointestinal system. Crohn’s disease, coeliac disease or ulcerative colitis are nowadays not only known to the most widely read gut professionals. In almost everyone’s circle of friends and relatives seems to be at least one suffering from a digestive disorder.

Sadly, for many conditions, there are no cures. But there are plenty of unorthodox treatment approaches: Faecal transplantation, medicinal use of cannabis and helminth therapy with Trichuris suis eggs or Necator americanus larvae (see also LT 5-2014). Whether disease prevalence has really increased (thanks to bad eating habits or genetic factors) or whether diagnosing has simply improved is just one of the many questions addressed by our gastroenterology and hepatology researchers in Europe (and, of course, elsewhere).

A growing concern

For our current publication analysis, gastroenterology and hepatology, we once again first turned our attention to the discipline’s specialist journals as identified by Thomson Reuters’ Web of Science database. We noticed that quite a few new journals have entered the publication scene, suggesting that, indeed, gastroenterological and hepatological issues are of growing concern for the scientific community and the general public. Gut and Liver as well as the Journal of Crohn’s and Colitis were both founded in 2007. Based on these expert journals, we subsequently compiled our list of most-cited nations, covering articles, reviews and proceedings papers but omitting meeting abstracts, editorial materials or news items. For the most-cited heads ranking, however, we included all journals, multidisciplinary as well as “monodisciplinary”.

Just as with dermatology (last LT issue), gastroenterologists and hepatologists also seem to prefer working in Germany. The country clearly leads the table in terms of total number of citations and articles but, on the other hand, has one of the lowest citation-per-article ratios among the top ten countries. If we had sorted our table according to citations-per-article, Germany would have been only 13th. The top three countries in this scenario: Belgium (30.9 citations per article), Scotland (30.2) and Austria (29.9).

England behind Italy, Greece in 11th place

Going back to the original table reveals two more surprises: Italy in the runner-up position leaves England, in third place, trailing in its wake and Greece misses the top ten by a hair’s breadth, or more accurately, 338 citations. European researchers, collectively, wrote more articles that gathered more citations than their US-American peers but, on average, American articles, once again, have been cited more often. This time, however, papers written in Canada (29.8) and Australia (27.2) did even better in this category. Enough about anonymous countries, let’s look at real people – our top 30 most-cited gastroenterologists and hepatologists in Europe, who penned articles, reviews or proceedings papers between 2005 and 2011.

For starters, though, we shall remain with nations. Where do our ‘digestive detectives’ work? As our nations’ ranking already suggested, most (14 of 30) are affiliated with a German university, located in Kiel, Frankfurt, Heidelberg or Leipzig. In contrast, although Italy scored second place in our nations’ ranking, no gastroenterologist or hepatologist from the southern European country managed to snatch a spot in our top 30 most-cited authors; but neither did a Greek scientist nor a Northern European scientist. Belgian researchers, however, did manage that feat – and not only one but four; all of them work in Leuven, at the city’s university or the University Hospital.

Among our top 30 are also two women, Séverine Vermeire (8th) and Cisca Wijmenga (9th). Interestingly, when we did the same publication analysis in 2008, covering work published between 1996 and 2007, not a single woman had enough citations to make our top 30. Things do, however, seem to change, slowly but surely.

Let’s move on from geography to topics. Our top five most-cited papers should give us a first hint about the hottest topics of the field. There, we have a genetics study on, amongst others, Crohn’s disease (1st), three papers about either the formation or treatment of cancer (hepatocellular carcinoma or intestinal cancer; 2nd, 3rd, 4th) and one paper about intestinal stem cells (5th).

This does not quite mirror the real research situation. According to our top 30 gastroenterologists and hepatologists, the most important and most widely studied topic in the field is Inflammatory Bowel Disease, in particular Crohn’s Disease (CD). Patients suffering from Crohn’s Disease have to put up with extreme tiredness, diarrhoea, weight loss and above all, horrible abdominal pain. “It’s like a gnawing pain right now (…) and then I have times where it’s perfectly fine but with intermittent sharp stabbing pains that last for a minute or so then go away, then come back and repeat!” describes a CD patient at a Crohn’s forum. No one knows what causes the disease but different triggers have been identified. The most common treatment: surgery.

Crohn’s Disease hot on research agenda

Almost half of our top 30 most-cited gut experts, a majority of them medical doctors, focus on this topic and approach it in two ways. Either through genetics (mainly Genome-Wide Association Studies) like Stefan Schreiber (1st), Séverine Vermeire (8th), Jack Satsangi (11th) and Philip Rosenstiel (22nd) or through finding ways to diagnose, control and treat the condition: Paul Rutgeerts (4th), Jean-Frederic Colombel (7th), who switched from the University of Lille to the Mount Sinai Hospital in New York, USA, in 2013, and Gert van Assche (28th).

Besides Inflammatory Bowel Disease, hepatitis, inflammation of the liver, is an important research topic for our gastroenterologists and, even more so for our hepatologists. Stefan Zeuzem (2nd), Michael Manns (6th), Patrick Marcellin (10th) and Thomas Berg (23rd) all work on ways to cure the disease. Ralf Bartenschlager (14th), who also scored 17th place in the virus research ranking (LT 7/2012), follows a different path to the same goal. He studies the first steps of hepatitis C virus infection.

What would a publication analysis be without our cancer researchers. Markus Büchler (5th), the two Spanish cancer specialists Josep Llovet (12th) and Jordi Bruix (13th), Peter Galle (17th), Helmut Friess (20th) and Pierre-Alain Clavien (25th), who want to attack cancers of the pancreas, liver and the colon with surgical or pharmaceutical precision.

Intestinal stem cells and microbes

And finally, there are the gastroenterologists and hepatologists, who were not so easy to pigeonhole into one of the three groups above. They are in a league of their own, so-to-speak. First and foremost Hans Clevers (3rd), whose scientific interest revolves around colorectal cancer but also around intestinal stem cells. Ernst Kuipers (18th) mainly works on Helicobacter infection, Joel Doré (27th) is known for his research on the human intestinal microbiome and, last but not least, Jan Tack (29th) who is committed to fathoming the enteric nervous system.

Many decades of studies on disorders of the digestive system have begun to bear fruit. Scientists have identified the first susceptibility genes, predisposing to, for instance, Crohn’s Disease and optimised treatments for patients suffering from hepatitis and cancers of the gastrointestinal tract and the liver. But we strongly believe that European gastroenterologists and hepatologists are still hungry for more.

View the Tables: Europe...and the World, Most Cited Authors...and Papers

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Last Changed: 20.11.2014