Rosacea Caused By Gut Problems?

Evidence Points To Gut Bacteria As Possible Cause

By Marc Braman, MD, MPH

Take Home:

Rosacea is a poorly understood condition, and typical treatment is less than ideal.  One study showed that most with Rosacea had an overgrowth of bacteria in the gut and that reducing the overgrowth cleared up rosacea for most people.  To fix the face we may need to treat the gut.

Antibiotic Mystery

Rosacea is a form of acne that affects over 14 million people in the U.S.  The majority don't realize they have this particular condition.  The redness in the face flares with warm temperatures, sunlight, spicy foods, etc.  It is well known that antibiotics make the common form of Rosacea get better, but it has not been understood why.  Studies have shown that the body is making an unusually large quantity of antimicrobial proteins.  So there is a fair amount of evidence pointing to some kind of infectious process - it has just not been clear what infection or where.

Gut-Only Antibiotic Study

A very enlightening study was published in 2008 in the official clinical practice journal of the American Gastroenterological Association, "Clinical Gastroenterology and Hepatology."  One hundred thirteen rosacea patients were compared with 60 healthy controls of similar gender and age.  They were tested to see if they had a condition called "small intestinal bacterial overgrowth" (SIBO) - which means just what is says: too many bacteria in the small intestine.  Patients with SIBO were randomly assigned to receive rifaximin for 10 days, an antibiotic the stays in the gut, or placebo.  They did the same for a group of rosacea patients without SIBO.  One month after treatment patients were tested to see if the SIBO was eradicated, and dermatologists used an objective scale to measure the status of the rosacea.


  • Patients with rosacea were much more likely to have SIBO (about 50%) compared to healthy people (about 5%).
  • In patients with rosacea and SIBO who were treated, 20/28 completely cleared and another 6/28 greatly improved.  Placebo patients didn't change.
  • Rosacea patients with SIBO who were initially given a placebo were then put on the rifaximin, with 17/20 eradicating the SIBO.  15/17 completely cleared their rosacea.
  • Rosacea patients without SIBO from the beginning were given rifaximin and 13/16 did not change.
  • Those who benefited from this approach had the excellent results last for at least 9 months.

Applying The Study Results

About half of people with rosacea may have an overgrowth of bacteria in their gut.  When these patients are treated with an antibiotic that stays in the gut, the vast majority have their rosacea go away.


Antibiotics have been used for years in treating rosacea.  However, usually even with oral antibiotics (that go through the gut and the whole system), the rosacea comes back after a time.  You have to give antibiotics again to clear it up.  This study found the benefits continued for 9 months - likely the end of the study period.  I am not sure how long most will benefit in the real world.  Perhaps this particular antibiotic reaches higher levels in the gut specifically and this is part of the better treatment outcomes.
Another question that comes up, is why does this condition exist in the first place?  Why isn't the bacteria in the gut in a state of balance and health?  Could be kinds of food being eaten, etc.
And what about the half that didn't have SIBO when they were tested?  We don't really know.  However, there is some evidence pointing to h pylori - the bacteria that has been found to cause stomach ulcers.  Perhaps this different kind of gut infection causes rosacea in some.  It is particularly hard to treat when you know you have it (3 medications at once to get rid of it most of the time).  If you don't know you have it, typical antibiotics may just suppress it while taking them but not get rid of it.

What Would I Do? 

If I had rosacea, I would want to know if I had SIBO (and probably h pylori).  I would likely use standard therapies (like rifaximin) to get things under control, and then see what I could do to keep my gut healthy as naturally as possible.  I would also be prepared for potential problems with insurance coverage for testing for SIBO and h pylori related to rosacea because it is not "standard" care.
Power to the people!

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Written 4/17/12.