SIBO, or Small Intestinal Bacterial Overgrowth Syndrome, is a condition in which there is an increased number of abnormal bacteria in the small intestine. If you are seeing symptoms such as bloating, abdominal pain or digestive problems, you may be suffering from SIBO.

Bacterial proliferative syndrome of the small intestine is a complicated and often difficult to diagnose ailment. It is often confused with other digestive problems, which can lead to long-term discomfort and more serious health problems. That’s why in this article we explain what SIBO is, what its symptoms are, and how the condition is diagnosed and treated.

What does SIBO consist of?

SIBO is a condition in which there is bacterial overgrowth in the small intestine. Under normal conditions, most bacteria are found in the large intestine. However, when they migrate to the small intestine and begin to multiply there, there is an overgrowth of the small intestinal bacterial flora. As a result, these bacteria ferment undigested food debris, which can lead to serious digestion and nutrient absorption disorders.

Symptoms of small intestine bacterial proliferative syndrome

The non-specific nature of SIBO syndrome symptoms makes the condition easy to confuse with other digestive diseases, including irritable bowel syndrome (ibs), making it difficult to make a proper diagnosis.

Symptoms that may indicate SIBO include:

  • The classic symptom is a tendency to have loose bowel movements, which may be accompanied by diarrhea,
  • bloating,
  • overflowing in the intestines,
  • sometimes weight loss.

Extraintestinal symptoms include:

  • depression,
  • chronic fatigue syndrome,
  • joint pain,
  • fatigue,
  • rosacea.

With the development of SIBO, symptoms of the disease such as:

  • thyroid diseases (hyperthyroidism and hypothyroidism- disrupt peristalsis);
  • diabetes, liver and kidney diseases;
  • celiac disease;
  • use of PPIs– proton pump inhibitors;
  • stress;
  • disorders of intestinal motor function (peristalsis) – such as in irritable bowel syndrome, systemic scleroderma, diabetes (diabetic neuropathy) or Parkinson’s disease;
  • anatomical abnormalities – stenosis of the intestine (after radiation therapy), post-operative adhesions in the abdominal cavity, bypassing bariatric surgery, condition after operations during which a fragment of the intestine – the ileocecal valve – was resected;
  • digestive disorders in the course of various diseases, for example: chronic pancreatitis, cystic fibrosis cirrhosis, chronic kidney disease;
  • taking certain medications – opioids or drugs that inhibit gastric secretion;
  • immunodeficiencies – IgA deficiency, HIV infection;
  • diverticular disease of the large intestine (anatomical impairment of paristalsis);
  • the occurrence of SIBO can also be caused by old age.

Causes of SIBO

The proliferation of bacterial flora in the small intestine can result from a variety of causes. SIBO is most often caused by:

  • disorders of intestinal motor function (peristalsis) – such as in irritable bowel syndrome, systemic scleroderma, diabetes mellitus (diabetic neuropathy) or Parkinson’s disease;
  • anatomical abnormalities – stenosis of the intestine (after radiation therapy), post-operative adhesions in the abdominal cavity, bypassing bariatric surgery, condition after operations during which a fragment of the intestine – the ileocecal valve – was resected;
  • digestive disorders in the course of various diseases, for example: chronic pancreatitis, cystic fibrosis cirrhosis, chronic kidney disease;
  • taking certain medications – opioids or drugs that inhibit gastric secretion;
  • immunodeficiencies – IgA deficiency, HIV infection;
  • diverticula in the small intestine;
  • the occurrence of SIBO can also be caused by old age.

Diagnosis of small bowel bacterial overgrowth syndrome

Untreated SIBO can lead to a range of gastrointestinal complaints, which can result in a significantly impaired quality of life, which is why getting the right diagnosis is so crucial.

Unfortunately, diagnosing SIBO can be a challenge, as the symptoms of SIBO are nonspecific and can resemble other intestinal ailments.

To diagnose SIBO, you should visit a gastroenterologist. The doctor, after taking a history of the symptoms, their nature, duration and accompanying diseases and examining the patient, will refer the patient for additional tests for SIBO.

The most commonly used diagnostic method for small intestinal bacterial overgrowth syndrome is the hydrogen breath test, with glucose or lactulose. The test with lactulose is recommended because of its greater specificity.

Other diagnostic methods include:

  • microbiological examination of the contents taken from the intestine during endoscopy (intestinal aspirate).

In addition, it is worth performing:

  • imaging studies, such as gastrointestinal x-rays (known as contrast infusion), magnetic resonance imaging (MRI) or computed tomography (CT), which can help rule out other causes of symptoms;
  • blood laboratory tests (blood count, vitamin B12 levels, albumin, folic acid).

Hydrogen breath test in the diagnosis of small intestinal bacterial proliferative syndrome

The hydrogen breath test is a non-invasive method for diagnosing SIBO.

The test involves ingesting a test substance (glucose or lactulose) and then measuring the levels of hydrogen and methane in the exhaled air. An increase in the level of these gases suggests the presence of an excessive number of bacteria in the small intestine, which ferment lactulose or glucose.

The test is performed on an empty stomach. In addition, on the day before the test, the patient must not eat fermentable foods (such as complex carbohydrates). The patient should remain fasting for 8-12 hours before the test, avoid smoking and limit exercise.

The patient should also stop taking antibiotics 4 weeks before the test, and prokinetic and laxative drugs about a week before the test.

SIBO treatment and diet

Treatment of SIBO involves several steps and is usually individualized depending on the cause and severity of symptoms. The primary therapeutic approaches are:

  • Diet: Changing to a diet low in fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) can help reduce symptoms. Other dietary approaches include a gluten-free, elimination or specific carbohydrate diet (SCD);
  • Antibiotic therapy: The use of antibiotics such as rifaximin, metronidazole or neomycin, which help reduce the amount of bacteria in the small intestine;
  • Probiotics and prebiotics: Introducing probiotics to treat SIBO can help rebalance the intestinal microflora, but their use for SIBO requires consultation with a doctor;
  • Treating comorbidities: identifying and treating underlying health problems that may contribute to SIBO, such as intestinal motility disorders, can be crucial to the long-term success of treatment.

SIBO is a complicated and often difficult ailment to diagnose, but with proper diagnosis and treatment, its symptoms can be effectively managed and quality of life improved. If you suspect you have SIBO, consult a gastrointestinal doctor, who will conduct the appropriate tests and recommend tailored treatment.