What is SIBO?

Understanding Small Intestinal Bacterial Overgrowth

What is SIBO?

Small Intestinal Bacterial Overgrowth (SIBO) is a digestive condition where an excessive number of bacteria grow in the small intestine. Normally, bacteria are more abundant in the colon, but when they overpopulate the small intestine, they can interfere with digestion, nutrient absorption, and overall gut health.

SIBO is often associated with bloating, digestive discomfort, and food intolerances, and it is frequently linked to conditions like Irritable Bowel Syndrome (IBS).

Symptoms of SIBO

SIBO symptoms vary from person to person, but the most common include:

✅ Digestive Symptoms:

  • Persistent bloating (often worsening throughout the day)

  • Excessive gas (flatulence)

  • Abdominal discomfort or cramping

  • Diarrhea, constipation, or alternating between both

  • Frequent indigestion or heartburn

✅ Nutritional & Systemic Symptoms:

  • Unintentional weight loss or difficulty maintaining weight

  • Vitamin and mineral deficiencies (especially B12, iron, and fat-soluble vitamins)

  • Fatigue and brain fog

  • Weak hair and nails due to nutrient malabsorption

  • Skin issues like acne, rosacea, or eczema

📌 Because SIBO symptoms overlap with IBS, it is estimated that up to 80% of IBS cases may be linked to undiagnosed SIBO.

What Causes SIBO?

SIBO develops when the normal mechanisms that regulate bacterial growth in the small intestine are disrupted. Some of the most common underlying causes include:

🔹 Slow Gut Motility (Poor Digestion Movement) – The small intestine relies on rhythmic contractions, called the Migrating Motor Complex (MMC), to clear bacteria into the colon. When this process slows down, bacteria can accumulate.

🔹 Low Stomach Acid – Stomach acid helps control bacterial growth. Conditions like hypochlorhydria (low stomach acid) or long-term use of proton pump inhibitors (PPIs) can allow bacteria to survive and multiply in the small intestine.

🔹 Structural or Surgical Changes – Scar tissue, adhesions, or prior surgeries (such as gastric bypass, C-section, or appendectomy) can create areas where bacteria get trapped.

🔹 Food Poisoning & Gut Infections – Certain bacterial infections, like E. coli or Salmonella, can damage the gut’s natural motility, leading to post-infectious SIBO.

🔹 Underlying Health Conditions – Disorders like IBS, celiac disease, Crohn’s disease, diabetes, or hypothyroidismcan disrupt gut function and increase the risk of SIBO.

📌 Identifying the root cause of SIBO is essential for long-term gut health and prevention of recurrence.

How is SIBO Diagnosed?

SIBO is typically diagnosed using a breath test, which measures hydrogen (H₂) and methane (CH₄) gas levelsproduced by bacteria fermenting carbohydrates.

Types of SIBO Breath Tests:

🔹 Glucose Breath Test – Glucose is quickly absorbed in the small intestine, making this test effective for detecting SIBO in the upper small intestine.

🔹 Lactulose Breath Test – Lactulose is not absorbed by the body, so it travels further down the small intestine, making it useful for detecting SIBO throughout the entire small intestine.

How the Breath Test Works:

1️⃣ Preparation – A special diet is followed 24 hours before the test to minimize background gas levels.
2️⃣ Drinking the Test Solution – The patient drinks a glucose or lactulose solution.
3️⃣ Breath Sample Collection – Breath samples are collected over 2-3 hours to track hydrogen and methane gas levels.
4️⃣ Result Interpretation – Elevated levels of hydrogen or methane within 90-120 minutes indicate the presence of SIBO.

📌 A healthcare provider can help determine the most appropriate test based on symptoms and medical history.

Who is at Risk for SIBO?

Certain conditions and lifestyle factors can increase the likelihood of developing SIBO, including:

  • People with IBS, celiac disease, or Crohn’s disease

  • Individuals with chronic bloating or gas after eating

  • Those who have taken long-term antibiotics or proton pump inhibitors (PPIs)

  • People with a history of food poisoning or gut infections

  • Individuals with diabetes, hypothyroidism, or autoimmune diseases

  • Anyone who has had abdominal surgery, adhesions, or motility disorders

📌 If you have chronic digestive issues, a breath test can help determine if SIBO is a factor.

Next Steps: Get Tested for SIBO

SIBO is a common but often overlooked condition that affects digestion, nutrient absorption, and overall well-being. If you experience persistent bloating, digestive discomfort, or unexplained nutrient deficiencies, a breath test can provide valuable answers.

📍 Take the first step toward better gut health today!
✅ Book a SIBO Breath Test 📩
✅ Schedule a Consultation 📞

Glucose Breath Test

How It Works

  • Glucose is a simple sugar that gets absorbed quickly in the first part of the small intestine.

  • If there is bacterial overgrowth in the upper small intestine, fermentation occurs, producing hydrogen and/or methane gases that appear in the breath test.

Pros

✅ More specific – Glucose doesn’t reach the colon, so positive results are less likely to be false positives.
✅ Best for detecting proximal (upper) SIBO – If bacteria are present early in the digestive process, glucose fermentation will reveal it.

Cons

❌ May miss distal (lower) SIBO – Since glucose is absorbed quickly, bacteria in the lower small intestine may not have time to ferment it.
❌ Less sensitive overall – Can under-diagnose SIBO cases where bacteria reside farther down in the small intestine.

Lactulose Breath Test

How It Works

  • Lactulose is a non-absorbable sugar, meaning it travels through the entire small intestine before reaching the colon.

  • Bacteria present anywhere in the small intestine ferment lactulose, producing hydrogen and/or methane gases.

Pros

✅ Detects SIBO in both the upper and lower small intestine – Ideal for identifying a broader range of cases.
✅ More sensitive – Catches more cases than the glucose test, especially if SIBO is located in the distal small intestine.

Cons

❌ Higher chance of false positives – Since lactulose eventually reaches the colon, fermentation there can be mistaken for SIBO.
❌ Results can be harder to interpret – The transition from small intestine to colon needs to be carefully considered in the analysis.

Which Test Should You Choose?

  • If you suspect SIBO in the upper small intestine, struggle with early bloating, reflux, or upper digestive symptoms, the glucose test may be a better option.

  • If your symptoms include bloating that worsens over time, constipation, or full intestinal discomfort, the lactulose test could be more effective.

  • If you are not sure, both tests would be considered for a comprehensive evaluation.

📌 Need a SIBO breath test? Book an initial consultation with Dr. Lococo, ND to discuss which test would be best for you.

Final Thoughts

Choosing between glucose and lactulose testing for SIBO depends on your symptoms and the suspected location of bacterial overgrowth. Glucose is more specific but may miss lower cases, while lactulose is more sensitive but has a higher risk of false positives.

🚀 Start your journey to better gut health today! 🚀