Probiotics - Published: February 2010
Interview Date: April 2010
From the Special Topic of
In our Special Topics analysis of probiotics research
over the past decade, Dr. Arthur Ouwehand's work ranks at
#2 by papers and #6 by cites, based on 81 papers cited a
total of 1,852 times. According to
Essential Science IndicatorsSM from
Reuters, Dr. Ouwehand's record includes 90
papers, the majority of which are classified under either
Microbiology or Agricultural Sciences, cited a total of
1,948 times between January 1, 1999 and December 31,
Dr. Ouwehand is currently the R&D Group Leader of
Danisco Health & Nutrition in Kantvik, Finland.
Below, he talks with
ScienceWatch.com about his highly cited work as it relates to
Please tell us a bit about your educational
background and research experiences.
Originally, I trained as a secondary school teacher in biology and
chemistry. Although I liked teaching, I soon realized that teaching
teenagers was not my calling. Also, unlike my fellow biology teachers, I
was not particularly interested in birds and plants, etc. I was more
interested in biochemistry, molecular biology, and microbiology. Although I
did get my degree in teaching, I continued to study at university, doing
cell biology and specializing in microbiology and biochemistry.
Though to my family I was of course still studying biology. I still have
bad memories of that; at birthday parties you always get aunts (never
uncles for some reason) asking about the identity of some plant they found
in the garden. "Arthur studies biology, so he should know that." I did my
Master's on topics in environmental microbiology, but that's not biology to
most people, unfortunately.
What first drew your interest to
As part of my Master's studies at Wageningen University of Agriculture (as
it was then still called) we had to do an internship. The strategy of the
university was always, "go abroad." Even if you would not learn anything
from your internship, you would at least know what it is like to really be
away from home.
"Supporting specific gastrointestinal and immune
functions is likely to remain at the core of
I ended up at the University of Gothenburg (Sweden) working on a project
with probiotics for pigs. That was interesting and I got an opportunity to
do my Ph.D. there on the topic. My main focus was adhesion of probiotics
and their effect on pathogenic E. coli. I did the last part of my
Ph.D. in Finland at the University of Turku where I continued working on
probiotics, but for humans. I continued to work there as a post-doc and
later as a senior lecturer, focusing on probiotics for humans; that seemed
more rewarding then probiotics for farm animals.
So, it was the interest in microbiology that, by chance, got me into
probiotics. At that time, probiotics was still a very new and maybe a bit
"obscure" area. Few products, if any were on the market and the average
consumer had certainly never heard of it.
Your most-cited clinical paper in our analysis is
the 2001 FEMS Immunol. Med. Mic. paper, "Comparison of
mucosal adhesion and species identification of bifidobacteria isolated
from healthy and allergic infants," (He F, et al., 30:
43-7, February 2001). Would you talk a bit about this study and its
findings, as well as how the results shaped your later
We had been working on adhesion of probiotics to mucus for some time. Of
course, at some stage you start to wonder how do "normal" intestinal
microbes bind? Not so surprising, that seemed to vary depending on the
isolated bacterium. You'll find anything from high and low binding strains.
We also wondered whether disease would play any role in this.
Furthermore, studies had indicated that at genus level there was a
difference in the fecal microbiota of children with atopic eczema compared
to healthy children. We wanted to look deeper; what about species level?
And indeed there was a maybe even more dramatic difference there. That is,
of course, interesting.
But, what was even more interesting is that the functionality of the
bacteria was different. They induced different cytokines and adhered in
different ways. This gave a first hint on the relation between an altered
microbiota and allergic disease. We have continued to work on the relation
between allergies and the intestinal microbiota.
What this study showed is that it is interesting to know who is there but
it is more important to know what they are doing. That is an idea that is
coming now with metabolomics and it is likely to be relevant for many
conditions. This study was performed in collaboration with Japanese
colleagues; having the right team is important to get the appropriate
Several of your papers involve bacterial adhesion
studies. Tell us a bit about this aspect of your work.
Most of my past work involved adhesion of probiotics and what role it might
play in efficacy and safety. I still think it is important, but, maybe not
as essential as we thought in the past. We have maybe been looking too much
for parallels with pathogens, for many of which adhesion is essential as a
first step in pathogenesis.
But it's possible that adhesion fulfills other roles than merely making a
microbe stick to a certain surface. The communication with the host is
maybe more important, for both parties.
Just last year, your group came out with a study
on probiotics for allergic rhinitis during the birch pollen season
(Ouwehand AC, et al., "Specific probiotics alleviate allergic
rhinitis during the birch pollen season," World J.
Gastroentero. 15: 3261-8, 14 July 2009). Would you discuss
the highlights of this paper and its implications?
"We had been working on adhesion of probiotics to mucus
for some time."
As an extension to the work with atopic eczema, the study was done on
pollen allergy in collaboration with my current employer, Danisco, and the
University of Turku. An earlier study had failed to show in improvement in
adults. We hypothesized that children might be more feasible as their
immune system is not fully developed.
Unfortunately for the study, but fortunately for the children, all received
prophylactic anti-histamines. Despite this strong and effective medication,
we were able to observe a reduction in biomarkers for birch pollen allergy.
Also some symptoms were further reduced, which is actually quite remarkable
considering that anti-histamines are very effective.
Another interesting observation was that the intestinal microbiota changed
during the pollen season—something that was more or less
simultaneously reported by Japanese researchers too. That may provide new
options for treating or alleviating this condition.
Where do you see probiotics going in the next
I am optimistic and do think that probiotics are here to stay. Supporting
specific gastrointestinal and immune functions is likely to remain at the
core of probiotics.
I would hope that for some serious intestinal diseases GMO (genetically
modified organism) probiotics would be accepted. There are examples of
their efficacy in Crohn's disease. For the general population I see
irritable bowel syndrome (IBS) as an important target. IBS is a collection
of different symptoms; I foresee that probiotics could aid in alleviating
some of these. It is a condition that is very common and thus has
substantial socio-economic implications.
Another interesting target is
obesity. With the observation
that the intestinal microbiota composition correlates with the risk of
obesity, modulation of the microbiota offers hopes in this area.
However, we should remain realistic. It is unlikely that consumption of
probiotics, or any other functional food ingredient, would solve a person's
weight problems. But, maybe probiotics can play a role in maintaining a
healthy weight or aid during weight loss. That all remains to be seen.
I also hope that pre- and probiotics find their way outside the gut. For
example, the skin has microbiota as well that are involved in health and
disease—that would be an interesting target.
Arthur Ouwehand, Ph.D.
Danisco, Health & Nutrition
Arthur Ouwehand's current most-cited paper in Essential Science
Indicators, with 201 cites:
Ouwehand AC, Salminen S, Isolauri E, "Probiotics: An overview of beneficial
effects," Anton Leeuwenhoek Int. J. Gen. M. 82(1-4): 279-89,
August 2002. Source:
Essential Science Indicators from
KEYWORDS: PROBIOTICS, HUMAN GUT, ADHESION, E. COLI, BIFIDOBACTERIA,
ALLERGIES, INFANTS, MUCUS, ATOPIC ECZEMA, CYTOKINES, INTESTINAL MICROBIOTA,
POLLEN ALLERGY, BIOMARKERS, POLLEN SEASON, CROHN'S DISEASE, IRRITABLE BOWEL
SYNDROME, OBESITY, PREBIOTICS.