Small Intestinal Bacterial Overgrowth (SIBO)

Small intestinal bacterial overgrowth (SIBO), also known as bacterial overgrowth or small bowel bacterial overgrowth syndrome, is exactly what it sounds like: an overgrowth of bacteria in the small intestine.

It typically happens when something causes the passage of food through your digestive system to slow down, making it easier for bacteria to multiply and causing uncomfortable symptoms like diarrhea, bloating, abdominal pain, and discomfort with eating. In severe cases, SIBO can also make it harder for your body to properly absorb nutrients, leading to weight loss and malnutrition.

Because SIBO symptoms come and go and often mimic other gut health conditions, you might struggle for a long time without getting answers, but the good news is that you’ve come to the right place.

Read on to learn about SIBO symptoms, causes, risk factors, and complications—and how we can help you find relief.

SIBO symptoms

Wondering if your symptoms might be SIBO or looking to better understand your condition? Let’s explore some of the signs of SIBO and get you the answers you need, whether you’re newly concerned or already have a diagnosis.

Typical SIBO symptoms include:

• Loss of appetite
• Nausea
• Abdominal pain
• Bloating
• Diarrhea or constipation
• Feeling uncomfortably full after eating
• Unintentional weight loss

According to research, SIBO is present in over a third of people with gastrointestinal (GI) symptoms—given what we know about how many people live with GI discomfort or a chronic GI condition, that’s a lot of people!

At Oshi Health, our GI specialists, including GI providers, registered dietitians, and gut-brain specialists, work together to address the root cause of your SIBO symptoms.

You don’t have to live with the discomfort of SIBO: Get started on your path to symptom relief in 3 minutes or less!

SIBO causes

In people with SIBO, the small intestine has an excessive amount of bacteria, which leads to uncomfortable symptoms like gas, bloating, and abdominal pain.

Causes of SIBO include:

• Certain medications. Antacids and proton pump inhibitors (PPIs) can lower the amount of acid in your stomach, making it easier for bacteria to multiply. Some medications, like opioids, anticholinergics, and antidiarrheals, slow digestion and cause food to sit in your GI tract. Frequent or long-term antibiotic use can also contribute to SIBO by disrupting bacterial balance in your gut.
• Surgery. Certain surgical-related changes to the GI tract or complications from GI surgery can interfere with your stomach’s ability to produce acid and control gut bacteria.
• Medical conditions. Hypothyroidism, scleroderma, immune deficiency, diabetes, gastroparesis, H. pylori, Crohn’s disease, celiac disease, liver disease, and other health conditions can promote bacterial growth in the small intestine.
• Structural problems of the small intestine. Physical blockages due to GI conditions or surgical complications and pockets called diverticulosis can make it more difficult for your small intestine to clear waste, boosting bacterial activity.

SIBO risk factors

Just because you have a risk factor doesn’t mean you’re destined to experience SIBO, but it can mean you’re more likely to develop the condition than someone else.

SIBO risk factors include:

• Being older. As you age, you produce less stomach acid, which can influence bacteria levels in your GI tract.
• Having had abdominal surgery or cancer treatment. Medical procedures like surgery or radiation therapy can impact the health and structure of your small intestine, making it more vulnerable to bacterial imbalances.
• Having a weakened immune system. If your immune system is less effective due to a health condition or treatment for a health condition, certain bacteria may have more opportunities to grow.
• Having a GI condition. There’s a strong link between disorders like irritable bowel syndrome (IBS) and Celiac disease and SIBO.

Evidence also suggests a possible link between SIBO and serotonin level changes. The hormone serotonin is a neurotransmitter, a chemical that acts as a messenger between the nerve and brain cells and cells throughout your body. It plays a role in regulating body temperature, sleep, sex drive, hunger, and mood—which is why it’s frequently dubbed the “feel-good chemical.”

Research suggests that about 90% of your body’s serotonin is produced in the gut. When your gut health is out-of-whack because of a condition like SIBO, it may lead to issues regulating serotonin production, impacting your overall emotional well-being—hello, gut-brain connection.

SIBO complications

SIBO can make it harder for your body to absorb nutrients, including macronutrients like fat, protein, and carbohydrates. In severe cases, SIBO can lead to malnutrition and nutrient deficiencies—that’s why it’s important to work with a registered dietitian who has experience with GI conditions like SIBO.

SIBO complications can vary depending on the particular type of nutrient deficiency. For example, being deficient in vitamin B12 can lead to anemia and problems with your nervous system.

Addressing the root causes of SIBO and managing your symptoms can make you less likely to experience complications.

SIBO diagnosis

The first step toward an SIBO diagnosis is a thorough medical history. At Oshi Health, our GI specialists consider the whole you when working together to make a diagnosis, including your medical history, symptoms, and lifestyle.

Your provider will ask you questions about your symptoms, like when they first started or whether certain foods or behaviors tend to make certain symptoms worse.

They’ll also consider the following:

• Your diet and potential trigger foods
• Lifestyle habits
• Any medications or supplements you’re taking or have already tried for your symptoms
• Stress and behavioral health
• Previous surgeries or medical procedures
• Your family history of GI conditions

And while you don’t need to have had previous testing to meet with an Oshi provider and benefit from our integrated GI care, your provider will review any previous testing you’ve gone through, if any.

Your provider may also recommend further testing to determine the root of your symptoms and check for complications. Testing may include:

• Blood tests Blood tests for SIBO can determine whether or not you have a deficiency due to poor nutrient absorption.
• Stool tests Stool tests for SIBO check for undigested bile acids and fats, which may signal you’re not absorbing nutrients properly.
• Imaging Imaging for SIBO looks for structural issues that may be contributing to poor GI function and emptying.

You may have also heard of breath testing for SIBO. A breath test can detect the amount of hydrogen or methane in your breath. High levels may mean your gut is overproducing gas-emitting bacteria or methane. But breath testing can be expensive, and may not always be reliable.

We try to avoid putting you through unnecessary and repeat testing. If our providers recommend diagnostic or other testing, we take a concierge approach to help you find a convenient and in-network location.

SIBO treatment

At Oshi Health, we take a comprehensive approach to SIBO treatment, addressing not just your symptoms but also uncovering and treating their root causes to put you on a path to better digestive health.

Here’s what that entails:

Prescribing or recommending medications

Medications are often part of personalized treatment plans for SIBO at Oshi Health.

Antibiotics are typically the first-line treatment for SIBO, helping to control bacterial overgrowth. Before prescribing antibiotics, our providers take into consideration any allergies you may have, previous antibiotic use, potential medication interactions with drugs or supplements you’re currently taking, and medical conditions that may make antibiotic use unsafe.

Commonly prescribed antibiotics for SIBO include:

• Ciprofloxacin
• Amoxicillin-clavulanic
• Doxycycline
• Metronidazole
• Neomycin
• Norfloxacin
• Tetracycline
• Trimethoprim-sulfamethoxazole
• Rifaximin

Your provider may also recommend supplements if you have a diagnosed nutrient deficiency resulting from SIBO.

Additionally, your provider may recommend medications, like magnesium oxide, to help with constipation due to SIBO.

Medications are just one piece of the journey to symptom relief. We take a whole-person approach to treating digestive health concerns, addressing not just your symptoms but also uncovering and treating their root causes to put you on a path to better digestive health.

Identifying triggers & making dietary and lifestyle adjustments

What does your typical diet look like? Do you have dietary triggers that seem to make your digestive symptoms worse?

Our registered dietitians will help you identify your symptom trigger foods and find ways to modify your diet without necessarily giving up the foods you love.

They may recommend:

• A soluble fiber supplement
• Targeted enzyme supplementation, if necessary
• Adjusting the amount of fat in your diet
• Assessing FODMAPs in your diet and limiting them if they’re a trigger for your symptoms
• Eating smaller, more frequent meals

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Working on the gut-brain connection

Did you know your brain and digestive system are in constant communication? It’s why you might feel butterflies in your stomach when you experience heightened emotions like stress or excitement.

The close link between your gut and mind can also play a role in gut health conditions like SIBO.

Our gut-brain specialists can help you identify potential stress-related symptom triggers.

Gut-brain specialists are trained and licensed behavioral health professionals with specific experience treating GI concerns like SIBO. Working alongside GI providers and registered dietitians, they can help you take control of your symptoms by providing you with the skills and tools to cope with distressing thoughts, feelings, and physical reactions that may be contributing to GI distress.

This might include:

• Relaxation strategies to manage stress, including diaphragmatic breathing exercises and mindfulness meditation
• Cognitive behavioral therapy (CBT) for GI symptoms to help you better cope with negative emotions that can worsen symptoms
• Acceptance and commitment therapy (ACT) for GI conditions to move towards a place of acceptance and identify the ways you might be avoiding certain situations, which could make it more challenging to cope with symptoms

Oshi Health gut-brain specialists are here to support you as you navigate living with a chronic digestive health condition, helping to normalize and validate your GI-related concerns—so you never feel alone in your journey to symptom relief.

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Whole person care for SIBO

At Oshi Health, no two treatment plans are the same.

Our GI specialists work together to create a personalized treatment plan to address the root cause of your symptoms. We consider the whole you—not just your SIBO diagnosis. That means taking into account diet, lifestyle, and the gut-brain connection, ensuring you get the individualized care you need.

Already seeing a GI provider? We can provide support between visits and work with your existing gastroenterologist as an extension of your care.

Ready to take control of your SIBO symptoms? We’re here for you every step of the way with virtual, next-day appointments. Get Started with Whole Person Care for SIBO Today!

Steph Coelho Written by Steph Coelho

Medically reviewed by Andrea Onstad, APRN, CNP