Interview: Prof. Peter Dettmar – the Role of Pepsin in LPR

Letzte Aktualisierung:
8. June 2024

Pepsin and LPR


A term that comes up often when you read about LPR.

At least when you are reading the information that has been written in recent time.

It has already been common knowledge for decades that acid is a factor in reflux. But that pepsin plays a crucial role too – this is a fact that just started to spread between medical professionals.

Professor Peter Dettmar was one of the first who researched pepsin and LPR. He has also developed Peptest, a new method to test patients for reflux – including LPR. I am very glad that he found the time for an interview here on Refluxgate.

Here comes the first part of the interview:

Part #1 – Pepsin

Hey Peter, thanks for taking the time to do this interview. To give my readers a better picture of what you do: how did you end up doing research about LPR?

I am a drug development expert in the pharmaceutical industry and I have a special interest in the gastrointestinal tract.

In the 80s, I started to develop products for esophagitis and symptoms of heartburn and regurgitation. One of the products I started to do some early development work with was the UK version of Gaviscon.

During that work, I realized that reflux is not only causing symptoms in the esophagus, like heartburn.

I realized that reflux could also reach the airways and cause damage there. So I started to further investigate on what damage reflux could do to the airways.

In the 90s, I contacted some investigators in the USA, including Jamie Koufman, whose name will come up quite a lot when you are studying treatments for LPR. We started to collaborate to research reflux and especially LPR.

Where did your investigation lead you?

When we started, everybody thought about reflux as a liquid.

However, we then began to realize the reflux that was reaching the airways was in most cases an aerosol or gaseous reflux.

So in LPR, you usually reflux very, very fine particles. You could call it a mist, or gaseous.

That also explained why it could cause symptoms in areas that are quite far away from the stomach: larynx, pharynx, lungs, ears and so on.

The fact that reflux can be a fine mist means it can penetrate much higher up and get into places that liquids wouldn’t reach.

How did you discover the role of pepsin for reflux diseases?

Most people thought it was the acid in the stomach that was causing the problems. But research has found this was not true.

We did some studies and were able to detect pepsin in the laryngopharyngeal area of people with LPR. On the other hand, the control group without LPR did not have any pepsin present.

That made it obvious that there must be some kind correlation between pepsin and LPR.

Jamie and I started to investigate what exactly is the role of pepsin in reflux.

What is the role of pepsin in reflux?

It became quite clear that it’s only acid in the presence of pepsin that actually causes damage.

Acid alone is no problem. But pepsin and acid together cause damage.

How does pepsin cause damage when you have reflux?

Pepsin is an aggressive agent.

Our studies showed it causes inflammation in tissues.

We saw that it causes damage to the surface of cells.

But we also think pepsin is taken into the inside of the cell. The medical term for that is endocytosis. The cell absorbs the pepsin; there it will damage the cell nucleus and mitochondria from the inside. It will cause the cell to kill itself, mutate itself.

So pepsin can cause surface damage, but it can also cause damage within the cells themselves and just destroy the cell nucleus. As a result, the cell stops functioning.

We found out later that pepsin is actually capable of sitting in those cells until reactivated.

A lot of my readers are freaking out about that. I get many emails asking about how long pepsin can actually stay in the cells and potentially cause damage.

It sounds quite drastic when you think something’s sitting in the cell to be sort of reactivated.

However, every time you eat, drink or talk, you shear your cells. There is a lot of movement and physical stress in the airways. As a result, cells are replaced very frequently. So it’s not like you’re going to reflux pepsin and it could sit there for months.

But it can sit in and on the cells for at least 24, maybe even 48 hours. It might even be longer. It is hard to put an exact number on it – with the research data that exists so far.

How deep can pepsin penetrate the cells in the airways?

We’ve done some electron microscopy on that.

It looks as if it could penetrate several cells deep. So pepsin won’t just be in the cells at the top of the epithelium.

Remember: cells are very tiny, so the distance is not that great.

So I talked with some therapists in Germany about this question, whether bad body posture could also cause your sphincters to malfunction. Is there anything you can tell me about that? Could a bad body posture be the reason for some people’s reflux?

It’s something you have to be aware of.

There’s a possibility that being stooped over a computer at a desk could cause reflux.

Also, people who do a lot of physical activity and bending will put additional pressure on the two esophageal sphincters. That increases the chance of reflux happening.

Another group of people who are very prone to reflux are athletes or runners, in particular. Also anyone who’s doing a lot of weights in a gym. A lot of marathon runners are refluxers. Their body size is perfect, they’re not overweight, they’ve got no excess fat, but they get reflux because of the pressure they put on their sphincters.

And, sure, being overweight is a very big influencer which increases the chance for reflux.

End of Part #1 of the Interview

The interview with Professor Peter Dettmar was packed with useful information. To make it easier to digest, I have split it into 4 parts.

If you want to go on with the interview: here you find part #2 about the symptoms of LPR.

I also recorded an in-depth interview with Professor Peter Dettmar on pepsin. You can find it in my online course LPR Solution Blueprint.

LPR Test

About the author 

Gerrit Sonnabend

Gerrit is a German data scientist & medical publisher. His formal education is in qualitative research. He had severe reflux himself. Read more about him here.