SIBO is one of the topics I'm asked about the most and I'm glad I finally
have the chance to dig into the research in this two-part video series.
I'll be answering the following questions: Is SIBO real?
How reliable are the diagnostic tests? Does a low FODMAP diet help?
And if you have SIBO or IBS symptoms, what should you do about it?
Let's go find out.
"Are Small Intestinal Bacterial Overgrowth (SIBO) Tests Valid?"
Gastrointestinal symptoms like abdominal pain
and bloating account for millions of doctor visits every year.
One of the conditions that may be considered for such a nonspecific
presentation of symptoms is SIBO: Small Intestinal Bacterial Overgrowth,
a concept that has gained popularity on the internet,
in addition to certain clinical and research circles.
SIBO is broadly defined as the excessive growth of
bacteria in the small intestine, and is typically treated with antibiotics.
But dispensing antibiotics to patients
with such nonspecifc, common symptoms is not without risks.
You could be fostering antibiotic resistance,
there could be side effects, and wiping out your good bacteria
could set you up for an invasion of bad bugs like C. diff,
all for a condition that may not even be real.
Even alternative medicine journals admit that SIBO
is being overdiagnosed, creating confusion and fear.
SIBO testing is overused and overly relied upon. Diagnoses are
often handed out quickly and without adequate substantiation.
Patients can be indoctrinated into thinking SIBO is a chronic condition
that cannot be cleared and will require lifelong management.
This is simply not true for most and is an example of the damage done
by overzealousness.
The monster that we now perceive SIBO to be may be no more than a phantom.
The traditional method for a diagnosis was a small bowel aspiration,
an invasive test where a long tube is snaked down your throat
to take a sample and count the bugs down there.
But this method has been almost entirely replaced with breath testing.
See, normally, a sugar called glucose is almost entirely absorbed
in the small intestine, so it never makes it down to the colon.
So if there is bacterial fermentation of that sugar, that suggests
you have bacteria up in your small intestine and can detect
that fermentation because the bacteria produce specific gases
that get absorbed in your blood stream and then are breathed out from
your lungs, which can then be detected with a breathalyzer-type machine.
Previously, a sugar called lactulose was used, but lactulose breath tests
weren't found to reliably detect the overgrowth of bacteria,
so researchers switched to glucose.
But when glucose was finally put to the test, it didn't work either.
The bacterial load in the small intestine was similar
for those testing positive or negative, so that's not a useful test either.
It turns out glucose can make it down to your colon after all.
They labeled the glucose dose with a tracer and found that almost half
of the positive results from glucose breath tests were false positives
because they were just fermenting it down in their colon
where your bacteria are supposed to be.
So patients incorrectly labeled with SIBO may undergo multiple courses
of antibiotics for a problem they don't even have.
Why do experts keep recommending breath testing then?
Oh, you mean the experts at the conference supported by
a breath testing company, most of whom had personally received funds
from SIBO testing or antibiotic companies?
And even if we could properly diagnose it, does it even matter?
In those with digestive symptoms, there is a range of positivity for SIBO
from approximately 4% to 84% —all over the map—
and there may be no difference in symptom scores between those testing
positive versus those testing negative, so testing positive could mean anything.
Who cares if some people have bacteria growing in their small intestines
if that doesn't necessarily correlate with symptoms?
Now antibiotics can make people with irritable bowel-type symptoms
diagnosed with SIBO feel better, so doesn't that prove SIBO was the cause?
No, because it can make just as many people feel better
who are negative for SIBO.
Currently rifaximin is most often used for SIBO, but it's not FDA-approved
for SIBO, so the cost can be prohibitive.
In fact, no drug has been approved for SIBO,
so even if you have good insurance, you may be shelling
out-of-pocket as much as $50 a day,
and you typically take it for two weeks.
And while antibiotics may help in the short-term,
they may make things worse in the long-term.
Those who are given a course of antibiotics are more than three times
as likely to report more bowel symptoms four months later than controls.
So what can we do for these kinds of symptoms?
That's exactly what I'm going to turn to next.