From the Guidelines
Colonic bacterial overgrowth, also known as Small Intestine Bacterial Overgrowth (SIBO), can lead to life-threatening bacterial translocation and should be treated with sequential antibiotic therapy to reduce malabsorption and improve nutritional status. The implications of SIBO are significant, and treatment is crucial to prevent complications. According to the most recent evidence 1, sequential antibiotic therapy is very effective in treating intestinal bacterial overgrowth and reducing malabsorption.
Treatment Options
- Poorly absorbable antibiotics such as aminoglycosides and rifaximine are preferred, but alternating cycles with metronidazole and tetracycline may be necessary to limit resistance 1.
- In clinical practice, the most commonly used antibiotics are metronidazole, amoxicillin-clavulanate, doxycycline, and norfloxacine 1.
- For patients with motility disorders, including those with dilated segments of residual small bowel, blind loop, etc., and who suffer from symptoms of bacterial overgrowth, occasional antibiotic treatment is recommended 1.
Importance of Treatment
- Bacterial overgrowth may lead to life-threatening bacterial translocation, making treatment essential to prevent this complication 1.
- Treatment can also improve nutritional status and reduce symptoms such as bloating 1.
- However, the routine use of antibiotics in patients with a preserved colon is not recommended, as it may interfere with energy salvage due to colonic bacterial fermentation of malabsorbed carbohydrate to short-chain fatty acids 1.
Dietary Modifications
- Dietary modifications, such as a low-FODMAP diet, may be necessary to manage symptoms and prevent recurrence 1.
- A low-FODMAP diet restricts fermentable carbohydrates for 4-6 weeks, followed by gradual reintroduction of foods to identify triggers.
- Prokinetic agents like low-dose erythromycin or prucalopride can help prevent recurrence by improving gut motility.
From the FDA Drug Label
Clostridium difficile-associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including XIFAXAN, and may range in severity from mild diarrhea to fatal colitis. Treatment with antibacterial agents alters the normal flora of the colon which may lead to overgrowth of C. difficile.
The implications of colonic bacterial overgrowth (Small Intestine Bacterial Overgrowth, SIBO) include the risk of developing Clostridium difficile-associated diarrhea (CDAD), which can range from mild diarrhea to fatal colitis 2.
- Key points:
- Colonic bacterial overgrowth can lead to CDAD
- CDAD can be severe and potentially life-threatening
- Antibacterial agents, including rifaximin, can alter the normal flora of the colon and contribute to the development of CDAD 2
From the Research
Implications of Colonic Bacterial Overgrowth (SIBO)
The implications of Small Intestine Bacterial Overgrowth (SIBO) include:
- Abdominal pain and distension, bloating, diarrhea, nausea, and weight loss 3
- Constipation in cases of intestinal methanogen overgrowth (IMO) 3
- Iron deficiency, anemia, deficiency of fat-soluble vitamins or B12 3
- Malabsorption of nutrients 4, 3
- Non-specific abdominal discomfort 5
Diagnosis and Treatment
The diagnosis of SIBO is challenging due to the low specificity of symptoms and the absence of optimal objective diagnostic tests 6.
- The breath test with detection of exhaled H2 is the most accessible technique, but requires rigorous performance and interpretation 3
- Treatment of SIBO remains empirical, with broad-spectrum antibiotics such as rifaximin recommended for 2 weeks 4, 7, 3
- Modifications of dietary habits and promotility drugs may also be used for symptomatic relief and maintenance of remission 4, 6