- Small intestinal bacterial overgrowth, or SIBO, is just as it sounds – there is too much bacteria in the small intestine.
- SIBO is one of those tricky conditions to diagnose and treat. There’s no perfect test, and standard treatments fall short or make matters worse.
There are diet and lifestyle changes you can take on to balance your intestinal microbiome.
- If you have somewhat regular bloating, diarrhea, nutrient deficiencies, or other digestive distresses, read on to decide whether or not you should open up a conversation with your doctor about SIBO.
You’ve been dealing with gas, bloating, diarrhea, or other similar stomach problems for years and have tried every diet and cure for IBS, with only minimal success. Research now suggests that SIBO, or small intestinal bacterial overgrowth, may be responsible for up to 78% of IBS cases. Because symptoms vary from person to person, it used to be that not many people got diagnosed with SIBO. Now, doctors and researchers are finding that it’s more prevalent than they thought, though exact numbers are unclear because SIBO is easy to miss. Read on to learn more about SIBO’s symptoms, how to get tested, and the best SIBO diet to follow.
What is SIBO
Small intestinal bacterial overgrowth, or SIBO, is just as it sounds – there is too much bacteria in the small intestine. The small intestine is a narrow, twisting tube that connects the stomach and the large intestine, or colon. Food gets mixed with gastric acid in the stomach before moving to the small intestine, where most digestion and food absorption occurs. While bacteria are essential for proper digestion, the majority of our gut bacteria resides in the colon. When bacteria migrate backwards into the small intestine, or proliferate for other reasons, it can lead to digestive distress, poor nutrient absorption, and even a leaky gut.
What causes SIBO?
Having a healthy gut depends on a lot of factors, and so many interconnected factors need to be humming along to keep your intestinal ecosystem in balance.
Two things that disrupt the balance of your gut bacteria include insufficient stomach acid and small intestinal dysmotility — a condition where something impaired the intestinal muscles, so the intestinal contents don’t move along as they should.
Sluggish intestines and SIBO
In a normal small intestine, muscular contractions push liquified food through the intestinal tube to the colon. When the muscles can’t contract properly, it’s due to a muscle or nerve (the impulse that controls the muscle’s movement) abnormality. If your intestines move partially digested food along too slowly, they can’t efficiently push bacteria into the colon for elimination. So, these bacteria continue to feed and proliferate in the intestine.
Several factors can affect the delicate muscles and nerves of the digestive system and cause intestinal dysmotility. Some nerve and muscle disorders are inherited. In these cases, it’s common to have family members who suffer from other contraction problems — either of the small intestine or bladder. Sometimes, they’re symptoms of other health conditions. The most common causes of intestinal dysmotility in the intestines include:
- Medications. To name a few: antibiotics, birth control pills, proton pump inhibitors, over-the counter antacids and NSAIDs.
- Endocrine disorders like thyroid disease
- Metabolic disorders, including diabetes
- Neurological disorders like enteric neuropathy and Parkinson’s Disease
Low stomach acid and SIBO
Another major cause of intestinal dysmotility and SIBO is low stomach acid. Getting your stomach acid under control ensures you’re breaking down your food before it enters your intestines, which helps speed along intestinal digestion. If partially digested food and microbes don’t have the chance to settle in and stay too long, your intestines won’t be as friendly an environment for the bacteria that have been proliferating and causing problems.
Low stomach acid can be tricky to identify, because it looks — and feels — like excessive stomach acid. Some of the more common symptoms include:
- Heartburn (frequently misinterpreted as too much stomach acid)
- Food allergies
- Mineral deficiencies
- Autoimmune diseases
- Undigested food in the toilet
- Candida overgrowth
- Skin issues like rashes, eczema, and hives
- Rectal or vaginal itching
It’s all too common that doctors diagnose low stomach acid as too much stomach acid. If you tell your doctor you have heartburn and some of the above symptoms, you’re likely to get a prescription for proton pump inhibitors which decrease stomach acid. PPIs make you more likely to develop H. Pylori overgrowth, which contributes to digestive problems and SIBO.
Take this test to figure out if you have low stomach acid. Then, try out these simple at-home remedies to increase stomach acid. Warning: Don’t try them all at once, or you could wind up with way too much stomach acid. Start your experimentation slowly.
Apple cider vinegar. A shot of apple cider vinegar before meals increases the acidity in your stomach. It also contains prebiotics that help balance your gut microbiome and keeps H. pylori in check.
Betaine hydrochloric acid (HCL) capsules. Start with one capsule of HCL (buy the kind with pepsin so you can digest both proteins and fats) at the start of each meal. If you do not get a warm, irritated, or generally uncomfortable feeling in your abdomen or esophagus, increase the dose to two capsules before meals. Increase the dose by a capsule every few days until you find an amount that gives you a mild warmness in your belly. Warning: Some medications like NSAIDs and corticosteroids do not mix well with HCl. Ask your doctor or pharmacist before you experiment with HCl tablets. They’re strong and can make an overproduction problem worse.
SIBO is one of those elusive conditions that doctors often sweep under a blanket diagnosis like irritable bowel syndrome, or they diagnose it as something else entirely.
Your SIBO symptoms may be radically different from your friend’s or your mom’s. It manifests in so many different ways, and there are a million different combinations of a long list of symptoms that can all point to SIBO.
SIBO can look like any combination of symptoms like:
- Abdominal cramps and pains
- Food allergies and intolerance
- Nutrient malabsorption
- Mineral deficiencies, specifically B12
- Autoimmune diseases
- Undigested food in the toilet
- Skin rashes, hives, eczema, rosacea
- Diagnosis of irritable bowel syndrome (IBS or IBD)
If you go to your doctor with any of the above, it’s probably worth opening up a conversation about SIBO.
Can you get a SIBO test?
Testing is tricky because short of surgery, the small intestine is hard to reach. Endoscopy only reaches the upper segment, and colonoscopy only reaches into the lower segment. That leaves over 15 feet of small intestine that you can’t access with a camera or for sampling.
Another problem lies in the available tests themselves. No test perfectly indicates the presence or absence of SIBO, and there’s no accepted standard among the medical community yet. So there’s a lot of subjective interpretation behind the scenes that combines test results with clinical symptoms.
Here’s what doctors have to work with so far.
Intestinal fluid aspiration
Intestinal fluid aspiration (aka duodenal aspiration, jejunal aspiration, etc.) involves taking a sample of fluid from sections of the small intestine and analyzing its bacterial profile.
Since the test is costly and it involves sedation and endoscopy, it’s not a typical doctor’s favorite test for SIBO, especially when symptoms are mild.
SIBO breath tests
Doctors are more likely to turn to breath testing to check for SIBO and H. Pylori. These bacteria feed off carbohydrates from food, creating fermentation gases, specifically methane and hydrogen. SIBO breath testing measures these gases.
Patients follow a strict diet for a few days prior to testing. On testing day, they will give a breath sample for a baseline measurement, then drink a solution of glucose or lactulose. After that, the lab will take additional breath samples over two or three hours and chart results over time.
Lactulose Breath Test (LBT)
When we consume lactulose in our food, we do not digest it. Bacteria have the enzymes to break it down, and after they do, they give off a gas. A breath test will pick up that gas, indicating how much bacteria is in there chowing down.
LBT can detect bacterial overgrowth in the hard-to-reach ileum of the small intestine. The downside is that it isn’t as sensitive a test as the glucose breath test.
Glucose Breath Test (GBT)
Unlike lactulose, humans absorb and use glucose. Humans absorb glucose in the first few feet of the intestine, and when we metabolize it, we use it as energy and do not produce the gas byproducts that bacteria produce. When bacteria consume glucose further down the intestinal tract, they give off hydrogen and methane, and the glucose breath test will detect that.
The GBT accurately picks up bacterial overgrowth in the duodenum (the first section of the small intestine), but not the ileum (the end). To cover the most ground, combine both tests.
Your doctor will get the numbers, then evaluate the result against your symptoms to come up with a diagnosis. Currently, there is no standard, so you can absolutely end up with a false positive or false negative diagnosis.
Urine Dysbiosis Test
You’re not likely to see this at your MD’s office, but if a functional medicine doctor is doing your evaluation, you might. This urine test detects by-products of yeast and bacteria originating in the small intestine.
This is another one your functional medicine doctor is more likely to use than an MD would be. A stool test shows the bacterial profile in the large intestine. High proportions of all bacteria (friendly and unfriendly) in the large intestine points to SIBO. Although this test isn’t definitive, your functional medicine doctor will evaluate the result against your symptoms to come to a conclusion.
The best SIBO treatment (and the worst)
Be cautious with antibiotics
The standard medical treatment for SIBO is a round of antibiotics. While antibiotics will knock out H. Pylori in the intestines for sure, it’ll also wipe out all of the friendly bacteria in your digestive tract. That obliterates your intestinal balance and opens you up to all kinds of havoc — digestive, mental, physical. Your gut flora affect how your entire body works.
While some extreme cases call for antibiotics, it might be worth talking to your doctor about whether you can make some diet and lifestyle changes first to see if things improve. A functional medicine or integrative medicine doctor is more likely to be ultra-conservative with antibiotics, and will be able to guide you through a more natural approach to balancing your gut flora.
Does the FODMAP diet cure SIBO?
Doctors may opt to prescribe a diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols, the FODMAP diet. The idea behind the FODMAP diet is that if you avoid some of the substances that bacteria break down that cause gas, distention, and other symptoms, you won’t have as many IBS or SIBO symptoms.
Problem is, the bacteria consume things other than the compounds in high FODMAP foods. So, they can still hang around, even when they’re not producing all the by-products that make you bloated and gassy. The FODMAP diet will reduce symptoms, which is a start, but it is not likely to cure SIBO.
A better way: attack SIBO in three phases
Approach SIBO as you would any imbalance in your gut, like leaky gut or candida overgrowth.
1. Starve the bad guys and feed the good guys
First, you want to stop feeding harmful bacteria so they stop getting busy and taking over. You can read more on balancing your gut bacteria. For now, follow these main SIBO diet tenets:
- Cut sugar, alcohol, low-nutrient carbs, and conventional dairy. These are the Animal House party for bacteria. Focus on a low-sugar, low-carb diet that emphasizes vegetables, protein and omega-3 fats. Fermented organic raw diary (like yogurt) might be okay — test yourself and see how you feel.
- Clean up your diet. If you eat a variety (emphasis on variety) of low-toxin, low-inflammation, nutrient-dense foods, no one bacterial strain will win over the others and you’ll get closer to a balanced intestinal ecosystem. That means, eliminating gluten, grains and mycotoxins, to start. Read more about how to clean your diet here.
- Avoid anti-nutrients, like phytic acid. Anti-nutrients deplete your minerals, and you want your system to have everything it needs to work properly and keep your flora in check. Eliminating grains is a good place to start. More on anti-nutrients here.
- Feed the good guys prebiotics. Prebiotics are friendly bacteria food. You can find the good stuff in green vegetables, coffee, and chocolate. You can also experiment with prebiotic resistant starches like banana flour, plantain flour, and raw potato starch. (Start slow with these and slowly increase your dose. A tablespoon of potato starch mixed in a glass of water is plenty.)
- Add collagen. Any microbial imbalance can lead to leaky gut. Hydrolyzed collagen protein has just what the gut lining needs to heal and seal.
2. Clear the harmful bacteria
Doctors prescribe antibiotics to clear the bacteria associated with SIBO. Research shows that herbal antimicrobials treat SIBO just as well as rifaximin, the most common antibiotic given for SIBO. Although natural herbal antimicrobials are much gentler on your system than prescription antibiotics are, you’re still killing off some of the good with the bad. Which leads to…
3. Rebuild your microbiome
Any time you make a change to your diet, your lifestyle, or even your sleep patterns, your microbiome adjusts. If you revamped your diet and attacked the harmful bacteria in your gut, your microbiome is most certainly out of whack for a while until it settles.
At this phase, the key is to encourage it to settle into the balance that will make you feel the best. You want just enough of each beneficial strain, and you want to keep the harmful strains in check. You can nudge it towards a balance that favors you with high-quality probiotics (specifically lactobacillus, bifidobacterium, and s. Boulardii strains) prebiotics (resistant starch), and a nutrient-dense, SIBO-friendly diet that includes enough vegetables to stuff a cow.
If you want a solution that’s tailored to your individual biology, a yearly Viome at-home test kit analyzes your gut biome via a stool sample. This will help you see where you are now, and provide tailored recommendations based on your microbiome’s make-up. You can test again as often as you want to see if what you’re doing is restoring the complex ecosystem in your midsection.
SIBO is one of those sneaky conditions that frequently stumps doctors. Current testing and treatment plans come with a lot of limitations. With a little research and by paying attention to how your body reacts, you can zero in on what’s going on and use the tools you have to balance yourself.