What causes SIBO?
Let’s review the 8 most common causes of SIBO.
The most common reason that SIBO comes back after treatment is that your doctor didn’t do enough to help you improve your sleep, stress or diet. If you are serious about healing SIBO then focus on your lifestyle first.
Diet and SIBO: The ways we eat can cause SIBO.
Cause 1: Meal Frequency
For a long time, we were told that the best way to lose weight and stay healthy is to eat small frequent meals. Unfortunately, this strategy often backfires when it comes to digestive health. Our modern habit of small frequent meals and constant snacking is a major reason why so many patients develop SIBO.
Because our bodies evolved in environments where food was scarce, our GI tracts become accustomed to long periods in between meals. Our GI system expects shorter windows of feeding and longer periods where it can recover and digest. This is why bodybuilders who eat small meals around the clock to gain weight commonly develop SIBO - the constant feeding disrupts the ability of the GI track to protect against bacterial overgrowth. It is also why many patients with SIBO feel so much better when they skip meals, restrict their eating to a smaller window or simply fast for a few days time.
Cause 2: Improper Diets. and Processed Food
In other cases, it is not how often we are eating that is the problem - but the types of food that are the problem. The most frequent culprit is a diet filled with processed, sugary foods.
In a fascinating and telling study, 106 Brazilian children were breath tested and their parents were asked about the families dietary habits. Researchers found a significant correlation between the intake of ultra-processed foods and presence of SIBO.
This is exactly what I see in so many patients, and another reason why it is so important to work towards minimizing the amount of processed foods that we consume in favor of whole and unprocessed foods.
Cause 3: High FODMAP Diets
Other times, it is the “healthy food” that is the problem!
Some foods (broccoli, apples, onions and garlic, to name a few…) are naturally high in fermentable sugars. These sugars are summarized in the acronym FODMAP. These sugars can feed bacteria in the small intestine and promote bacterial growth. While people with robust GI systems can eat these foods without problems, other patients are uniquely sensitive to FODMAP intake. You may understand how incredibly frustrating it is for to try and make good food choices and feeling bloated and nauseous as a result. It’s no wonder that some simply throwing their hands up and give up.
For some: the healthier they eat, the worse they feel. This is usually the result of people with SIBO inadvertently eating high FODMAP diets.
The key to helping these patients is finding the right types of healthy foods for their systems that will not trigger symptoms and instead let the GI system heal.
For many, working on sleep, cleaning up the diet, and stress reduction fasting goes a long way to reducing symptoms. But if you are one of those who has already done work cleaning up your lifestyle and are are still having symptoms - then it’s time to add additional treatment. For most patients, this means adding probiotics.
Poor sleep drives SIBO.
Cause 4: Poor or insufficient sleep
Many of my patients have SIBO because they have been shortchanging their sleep. This is because being low on sleep sends a very strong signal to the nervous system that things are not okay.
Historically, early humans would forego sleep only to scavenge more food in the face of starvation, to escape from predators or flee from a natural disaster. As a result, when you are sleep deprived, your body’s survival instincts kick in and assume that you are threatened. Your nervous system begins making stress hormones to raise your blood pressure rather than stomach acid to break down food and sterilize the small intestine. It prioritizes building immune cells for defense, rather than bile to break down fats. The body will moves blood away from your intestines where it accepts nutrients and nourishes the GI lining to your muscles for movement. Together, all of these changes mean that the normal production and function of stomach acid, bile, and digestive enzymes are decreased. Less digestive juices allows more bacteria to grow in your small intestine, and you get SIBO.
Stress worsens GI function and can causes SIBO.
Cause 5: Chronic stress
It is quite common for an intense period of stress to precede someone’s SIBO diagnosis.
A similar process happens when the body feels constantly stressed, overtaxed and overwhelmed. In response to stressful emotional states, the body shifts away “rest and digest” and towards “fight or flight.” Of course, this doesn’t happen overnight, but slowly occurs over months and years. It is for this reason that SIBO can gradually arise over time.
Medications can cause SIBO
Cause 5: Antibiotics
Although taking medications is not strictly a lifestyle problem, it is one of the most frequent causes of SIBO and deserves special notice.
Antibiotics, especially “broad spectrum” antibiotics that kill a wide variety of bacteria directly cause SIBO by reducing the number and diversity of beneficial bacteria in the small intestines. This makes it much more likely for problematic bacteria to take over and start causing problems. However, it is important to note that it is quite rare for a single course of antibiotics to cause SIBO - it is much more common for a patient to come to my office with SIBO after they were given several courses of antibiotics in a short period of time. Another common scenario causing SIBO is the practice of dermatologists prescribing drugs like doxycycline or minocycline to be taken long term to suppress acne.
Cause 6: Proton Pump Inhibitors
Proton pump inhibitors are very strong suppressors of stomach acid, and can quickly help someone with severe acid reflux or ulcers. However, these medications are designed to be used in the short term. There are about 15 million Americans taking PPIs and many of these folks are taking them year after year after year. I wish that the doctors who are prescribing lifelong courses of these medications would review the FDA’s package insert on these medications.
“PRILOSEC is indicated for short-term treatment (4-8 weeks) of active benign gastric ulcer in adults.”
“PRILOSEC is indicated for the short-term treatment (4-8 weeks) of erosive esophagitis that has been diagnosed by endoscopy in pediatric patients and adults… The efficacy of PRILOSEC used for longer than 8 weeks in these patients has not been established.”
“PRILOSEC is indicated to maintain healing of erosive esophagitis in pediatric patients and adults. Controlled studies do not extend beyond 12 months”
Cause 8: Gastroenteritis AKA “Stomach Bugs”
Last, but not least, are the cases of SIBO that occur shortly after experiencing a stomach bug. In these cases patients describe a run of the mill stomach bug - a few days of nausea, diarrhea and perhaps vomiting. But instead of things going back to normal, they find that they are bloated all the time, have stool irregularity and abdominal pain. The latest thinking is that these post-infectious SIBO cases are driven by viral disruption of the normal motility. What is important to understand is that if your chronic GI symptoms began shortly after a stomach bug, then you should ask your doctor to consider SIBO as part of their workup!
Cause 7: NSAIDS
NSAIDS are drugs like ibuprofen, diclofenac, celebrex that are common prescribed by doctors to reduce musculoskeletal pain. There is absolutely nothing wrong with using these medications in the short term. However, longer term use of these medications is directly toxic to the cells that line the GI tract, and prolonged use is associated with all sorts of GI problems. I have had a few patients that simply did not heal until we found alternatives to the ongoing daily doses of these medicines - but once they were weaned off their GI symptoms resolved quickly!
The paper on the right looked at patients who had been using NSAIDS for 3 months. More than half of these patients were found to have severe intestinal damage from the NSAIDS, and intestinal damage made it more likely for a patient to develop SIBO. 25% of the patients who had been on NSAIDS without severe damage developed SIBO, while 60% of patients with severely damaged intestines tested positive for SIBO.