They carried it inside in bucket loads. During an interview with Radio Rijnmond, Maikel Peppelenbosch – popularly known as the poo professor – had mentioned that he didn’t have enough poo. He had enough poo from sick subjects, but from healthy people: nothing.

A couple of students at a loose end heard of his predicament and rustled up some students – or rather their bowel movements – from a couple of student houses. He laughs: “They brought me masses of the stuff. Of course, we couldn’t use it, but they thought they were doing me a favour. We gave them a beer for their trouble.”

Maikel Peppelenbosch loves telling stories. And he has quite a few to tell. Because while most medical experts rarely leave their labs, he gets into one adventure after another. You’re either a professor of experimental gastro-enterology or not. So he’s pushed subjects, drips and all, from a bungee jump platform. He’s collected poo from thousands of Rotterdam residents. And he gave astronaut André Kuipers an experiment to do on his first trip into space (which all went terribly wrong and created a media frenzy).

As a medical expert, how did you get involved in space travel?

“We do research into how the immune system works. If you know how that works, you can control it. By strengthening it, or slowing it down, which can be necessary in an autoimmune disease like Crohn’s. We knew that astronauts had a suppressed immune system. We wanted to understand that. And exactly at that time – we’re talking about 2004 – the former minister decided that it was time another Dutch astronaut should be rocketed into space. In order to justify the budget, scientific research was required. So we were there at the right time.”

Peppelenbosch op de lanceerbasis in Kazachstan.

So did you attend the rocket launch in Kazakhstan?

“Yes, on a steppe with the minister, with the President of Kazakhstan, with all kinds of Russian generals. The NOS was even there for a film in which I tell André Kuipers: here’s the documentation for the experiment and hand him a copy of Tintin’s Explorers on the Moon.”

It didn’t all go entirely to plan, which you did not try to conceal.

“It was a stressful mission. We’d taken a lot of trouble to organise everything. What irritated me was that nothing was arranged for us. We flew from Moscow to Bajkanour, on a flight packed with VIPs and journalists, whose every need was catered for, while the three of us could only just get on board and had to pay everything ourselves. When we got there, we also had to pay fifty thousand dollars in cash to rent the facilities. That annoyed me and I said so to a journalist from the Volkskrant. The next day, it was splashed all over the front page.”

And then?

“All hell broke loose. The minister initially denied it, but later reluctantly admitted that something had gone amiss ‘in the communication’. Peppelenbosch-gate, the newspapers called it.”

To make matters worse, the experiment also went wrong. What happened?

“The power supply was never switched on.”

You mean: André Kuipers forgot to put the plug in the socket?

“At the ESA, they call it a technical fault. But that’s more or less what happened. Yet at the time, the NRC – and I think rightly – reported that our research was the main reason to justify this ‘thirty million euro adventure’. Well, it was a good dinner party story. And eventually we were able to repeat the experiment with a sounding rocket and published the results in Nature Scientific Reports.”

Maikel Peppelenbosch.

Cowboys in Science

For the series Cowboys in Science, Geert Maarse interviews researchers who go a bit further than their colleagues. Maikel Peppelenbosch is Professor of Experimental Gastroenterology at Erasmus MC. He did his PhD in Utrecht, worked at the AMC and was a professor in Groningen, before coming to work in Rotterdam. For his research into how the immune system works, he did numerous experiments under extreme conditions. For one of his experiments, he worked with the European Space Agency ESA. A publication is about to appear documenting research for which they got patients with autoimmune pancreatitis to drink marihuana.

Bungeejumpen voor de wetenschap.

You also put respondents on a bungee jump platform. Why was that?

“We know that stress has a great impact on the immune system. But it’s very difficult to stress people in a controlled way. We tried to take blood from students before they presented their graduation project, but that proved too instable. Then we found a publication by a German group which claimed that you can stress people if you put them on a thirty metres high bungee jump platform. We thought: we could do that. So we not only put people up on a high platform, we also pushed them off. With a drip, so that we could measure the blood during the jump. That produced a great response and an acute reaction in the congenital immunity – macrophages that eat bacteria – which continued for a good 48 hours.”

It could have gone wrong?

“If you don’t take a risk, you don’t get anywhere. My most cited article is a study for which we created bacteria using genetic modification which suppressed the immune system in such a way that it would be life-threatening if they escaped. Ten patients were involved, lying in special depression chambers. That produced amazing results, but even as far away as Germany, they wondered if we hadn’t gone too far.”

Now you’re collecting piles of poo. How many samples are there?

“We’re part of extensive cohort studies, like ERGO, Generation R and the bowel cancer screening. I should think we’ve got poo from around 25,000 people in the freezer.”

Where’s that freezer?

“Just around the corner.”


“No, it’s all processed in a very sterile way.”

Billionaire’s poo

“We have a lot of money available for our research,” says Peppelenbosch. “Crohn’s Disease, which is one of our key focuses, disproportionally affects many rich people. What smoking is to lung cancer, money is to Crohn’s. Students are collecting billionaire’s poo to find out if they have different intestinal flora. It’s being funded by one of the richest men in the world, Eli Broad, whose son has the disease.”

What do you hope to learn from this study?

“The composition of our intestinal flora has a great impact on our health. Everyone knows the phenomenon that pregnant women suddenly feel like eating gherkins. That’s because the composition of the intestinal flora changes, to allow the baby to grow. But we don’t yet know exactly how such functional responses work. By constantly screening people, you can define triggers for bowel cancer, for example, a disease that kills five thousand people a year. A Nobel Prize has already been won for the discovery that the helicobacter pylori bacteria causes stomach ulcers. If those Australian researchers can do it, so can we.”

Is that Nobel Prize the drive for the research?

“Our role is to make patients better. But gastroenterologists are cowboys too. So there’s a kind of sportsmanlike rivalry with the AMC in Amsterdam. I sometimes compare it to the Italian Renaissance. Genoa, Florence, Sienna – they all tried to do things better. And that competition produced some great things.”

What experiment can we expect in the future?

“We’ve written a proposal for a study in the South Pole. Like with the ESA, Europe has called for a scientific study on location. There’s a very strong polar-equatorial gradient for inflammatory intestinal diseases. In other words: we want to know why the immune system works differently at the equator than at the Poles. We’re going to start studying that very soon.”