From the Guidelines
Small intestinal bacterial overgrowth (SIBO) should be treated with rifaximin (Xifaxan) 550mg three times daily for 14 days as the primary antibiotic treatment, along with dietary changes and addressing underlying causes, to reduce morbidity, mortality, and improve quality of life. The treatment of SIBO involves a multi-faceted approach, including antibiotics, dietary management, and addressing underlying conditions.
Antibiotic Treatment
- Rifaximin is the preferred antibiotic due to its local action in the gut and minimal systemic absorption 1.
- Alternative antibiotics such as neomycin, metronidazole, or ciprofloxacin may be used in combination for different bacterial types, but with caution due to potential side effects such as peripheral neuropathy and tendonitis 1.
Dietary Management
- A low-FODMAP diet can help reduce fermentable carbohydrates that feed bacteria, and should be implemented in three phases: elimination (2-6 weeks), reintroduction, and personalization.
Addressing Underlying Causes
- Prokinetic agents like low-dose erythromycin (50-100mg at bedtime) or prucalopride may help prevent recurrence by improving intestinal motility.
- Treatment should also address underlying conditions such as adhesions, structural abnormalities, or motility disorders. Some key points to consider in the treatment of SIBO include:
- Recurrence is common (up to 44% within one year), so some patients may require cyclical antibiotic treatment or ongoing dietary management.
- Probiotics and herbal antimicrobials may provide additional support, but have less consistent evidence than antibiotics 1. It is essential to prioritize the treatment of SIBO to reduce morbidity, mortality, and improve quality of life, especially in patients with chronic pancreatitis, where SIBO may complicate the condition in up to 92% of patients 1.
From the Research
SIBO Treatment Options
- Broad-spectrum antibiotics are the first-line treatment for small intestinal bacterial overgrowth (SIBO) 2
- Alternative therapies such as probiotics, therapeutic diets, and herbal medicines have been used to individualize SIBO management, particularly in recalcitrant cases 2
- Rifaximin is a broad-range, gastrointestinal-specific antibiotic that demonstrates no clinically relevant bacterial resistance and may be useful in the treatment of SIBO 3
Efficacy of Rifaximin in SIBO Treatment
- Rifaximin improved global symptoms in 33 - 92% of patients and eradicated SIBO in up to 84% of patients with IBS 3
- The overall eradication rate of SIBO according to intention-to-treat analysis was 70.8% (95% CI: 61.4-78.2) and to per protocol analysis 72.9% (95% CI: 65.5-79.8) 4
- Rifaximin treatment seems to be effective and safe for the treatment of SIBO, with a dose-dependent efficacy and commonly associated with the improvement of the gastrointestinal symptoms and underlying diseases 5
Comparison of Antibiotic Therapies
- Antibiotics appear to be more effective than placebo for breath test normalisation in patients with symptoms attributable to SIBO, and breath test normalisation may correlate with clinical response 6
- Rifaximin was the most commonly studied antibiotic with an overall breath test normalisation rate of 49.5% (95% CI 44.0-55.1) 6
- Meta-analysis of four studies favoured antibiotics over placebo for breath test normalisation with an odds ratio of 2.55 (95% CI 1.29-5.04) 6
Limitations and Future Directions
- There may be studies not captured by the defined search criteria, and studies used different methodologies in both breath testing and measurement of clinical symptoms, making it difficult to draw conclusions on SIBO eradication and symptom improvement across studies 2
- Large-scale, randomized, placebo-controlled trials are needed to further evaluate the best way to utilise alternative therapies in the treatment of SIBO 2
- Well-designed RCTs are needed to substantiate the findings and to establish the optimal regimen for rifaximin treatment of SIBO 4