Understanding SIBO and Hydrogen Breath Testing

What is SIBO?

SIBO (or Small Intestinal Bacterial Overgrowth) is a condition where abnormally large numbers of bacteria normally found in the large intestine inhabit the small intestine.

These bacteria are naturally present in the large intestine to help with digestion and to aid in other metabolic processes such as making Vitamin K; however, when they start to overpopulate the small intestine they can cause problems.

But I thought bacteria in the gut are good?

They are…in the right amounts, in the right places, in the right quantities, and the right types.

Bacteria are present naturally in the gut and play an important role in normal bowel health and digestion. They aid in digestion and help prevent infection by destroying harmful bacteria and other microorganisms. They also produce vitamin K. A complex ecosystem of over 500 bacterial species lives in the gut. Some of these bacteria are good; others are not. Most are found in the large intestine.

Just like a fingerprint, we each have a unique makeup to our gut flora determined partly our mother’s gut flora, or the bacteria we were exposed to while in utero, and partly by our own diet and lifestyle. Gut bacteria are different in healthy vs. unhealthy individuals with research tying gut bacteria to the development of many diseases including: diabetes, obesity, fatty liver, heart disease, depression, rheumatoid arthritis, inflammatory bowel disease, IBS, anxiety, autism, and even colon cancer.

People with IBD are believed to have lower levels of certain anti-inflammatory bacteria present in their gut. The exact connection is unclear but it’s thought that some bacteria may cause the immune system to attack the intestines setting the stage for this disease.

Studies show that people with colon cancer might have a different gut microbiota, including higher levels of disease-causing bacteria, than healthy people.

Patients with rheumatoid arthritis may have greater amounts of a bacteria linked to inflammation than people without it.

Why are bacteria a problem then in the small intestine?

The small intestine is responsible for 90% of the digestion and absorption of nutrients and minerals from our food. By the time food gets to the large intestine, the majority of digestion and absorption has already occurred. The large intestine is responsible for absorbing water and electrolytes, forming and storing feces, and transmitting useless waste out of our bodies. It maintains a resident population of over 500 species of bacteria that ferment indigestible materials.

In the small intestine food is still in the process of being broken down and digested. Carbohydrates have yet to be broken down, digested and absorbed, unlike in the large intestines, and bacteria like carbohydrates. They thrive in this high carbohydrate environment, feeding off of undigested carbohydrates. As bacteria consume carbohydrates they produce gas as a byproduct of fermentation. SIBO results, eliciting excess gas, bloating, diarrhea and abdominal distention in affected individuals.

How does SIBO develop?

Under normal circumstances, during periods of fasting throughout the day, undigested food is propelled from the small intestine into the colon via the migrating motor complex (MMC), or our internal intestinal “ housekeeper”. Roughly every two hours, the small intestine initiates this “housekeeper wave” that sweeps through the small intestine and dumps everything including excess bacteria, food, digestive enzymes, bowel secretions and other digestive contents into the large intestine where water can be reabsorbed before fecal material is excreted from the body.

When something impairs this housekeeper wave and the migrating motor complex fails to effectively sweep small intestinal contents clean as a result of food moving through the digestive tract too quickly, motility disorders, diarrhea, or other problems, the small intestine can’t expel the bacteria and bacterial overload (or SIBO) occurs.

Bacteria in the small intestine produce and release hydrogen and other substances into the colon causing gas, bloating, excess water secretion and diarrhea.

What are the symptoms of SIBO?

Symptoms of SIBO are non-specific, but can include:

  1. Abdominal pain or discomfort,
  2. Abdominal distention,
  3. Gas,
  4. Bloating,
  5. Diarrhea,
  6. Dyspepsia,
  7. Constipation (although not typical),
  8. Improper digestion or malabsorption of fats and proteins, and
  9. Weight loss (in severe cases).

What are the risk factors for SIBO?

Risk factors for developing SIBO include:

  1. Structural or anatomic issues (for example, individuals with a history of GI surgeries or gastric bypass surgery may be at increased risk),
  2. Motility disorders (like gastroparesis, dumping syndrome, GERD, chronic constipation, diarrhea, or IBS),
  3. Organ system dysfunction,
  4. Chronic disease,
  5. Elderly age, and
  6. Taking various medications (such as recurrent antibiotics or proton pump inhibitors) that alter the gut microflora.

What conditions are associated with SIBO?

  1. IBS
  2. IBD (Crohn’s disease or Ulcerative Colitis)
  3. Celiac Disease
  4. Diabetes
  5. Fibromyalgia
  6. Rosacea
  7. Parkinson's Disease
  8. Obesity

How can I be tested for SIBO?

Testing by Hydrogen Breath Test is performed to diagnose the condition.
Using a Hydrogen breath test to diagnose SIBO is a simple, non-invasive and inexpensive way to find out if you are affected with the condition. The test takes roughly three hours and is performed in our Flemington office.

How is SIBO treated?

The mainstay of treatment is antibiotic therapy and addressing any underlying contributing conditions.

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