SIBO Treatment UK: Your Complete Guide
If you’ve been diagnosed with Small Intestinal Bacterial Overgrowth (SIBO), or you’re trying to make sense of a positive SIBO breath test, this SIBO Treatment UK guide will provide all the information, especially if you’re wondering: what happens next? What does SIBO treatment actually look like, and how do you know which approach is right for you?
The good news is that SIBO is treatable. The less straightforward news is that there’s no single ‘correct’ treatment that works for everyone. SIBO is a complex, often multi-layered condition, and effective treatment needs to account not just for the overgrowth itself, but for the underlying reasons it developed in the first place.
In this guide, we walk you through the different treatment approaches available in the UK, how to think about which might suit your situation, and what to do if SIBO keeps coming back.
What is SIBO treatment?
SIBO occurs when bacteria that should be largely confined to the large intestine migrate into and colonise the small intestine in excessive numbers. This disrupts normal digestion and absorption, and patients commonly experience symptoms including bloating, abdominal pain, diarrhoea, constipation, fatigue and nutritional deficiencies.(Ahmed et al. 2023; Quigley et al. 2020)
SIBO treatment therefore has two broad goals:
- Reduce the bacterial overgrowth in the small intestine
- Address the underlying factors that allowed it to develop and persist
Without addressing both, the risk of recurrence is high. A round of antimicrobials or antibiotics may reduce symptoms in the short term, but if the root cause — whether that’s impaired motility, low stomach acid, a gastrointestinal infection such as food poisoning, structural issues, or chronic stress — remains unaddressed, the bacterial overgrowth tends to return.
This is why, at IBS & SIBO Clinics, we never treat SIBO in isolation. We look at the full clinical picture to understand why the overgrowth has occurred before deciding on the most appropriate treatment pathway.
SIBO treatment options: what are the approaches?
Effective treatment typically draws on a combination of antimicrobial or antibiotic protocols, short-term dietary modification, and in more complex cases, an elemental diet. The right combination largely depends on your SIBO type, symptom history, and the underlying drivers that allowed the overgrowth to develop.
Pharmaceutical antibiotics
The most well-researched antibiotic for SIBO is rifaximin (brand name Xifaxan). Unlike most antibiotics, rifaximin undergoes minimal absorption into the bloodstream, working locally in the gut, which means it delivers a relatively targeted action with fewer systemic side effects.(Sachdev & Pimental 2013)
For hydrogen-dominant SIBO, rifaximin is the most commonly used option. For methane-dominant SIBO (also called Intestinal Methanogen Overgrowth, or IMO), practitioners often combine rifaximin with neomycin or metronidazole, as methanogenic archaea respond differently to treatment than bacteria.(Quigley et al. 2020)
In the UK, rifaximin is not licensed for SIBO treatment and therefore not routinely prescribed on the NHS. It can be prescribed privately, and this is the route most people pursuing pharmaceutical treatment will need to take.
Herbal Antimicrobials
Herbal antimicrobials (plant-based compounds with antimicrobial properties) are widely used in functional medicine practice as an evidence-informed alternative to antibiotics. Research, including a notable study published in the journal Global Advances in Health and Medicine, has found that herbal protocols can be as effective as rifaximin in treating SIBO in some cases, as well as benefiting non-responders to rifaximin treatment.(Chedid et al. 2014; Nickles et al. 2021)
Commonly used herbal antimicrobials include:
- Berberine — broad-spectrum antimicrobial activity
- Oregano oil — contains carvacrol and thymol with antibacterial properties
- Allicin (from garlic) — can be particularly useful for methane-dominant SIBO
- Neem, pau d’arco, and wormwood — used in some combination protocols
Herbal protocols typically run for four to six weeks and practitioners often use them in combination. They are generally well tolerated, though working with a practitioner to select the right combination and dose for your specific pattern of SIBO is important.
The elemental diet
For severe, refractory or complex SIBO cases, an elemental diet — a pre-digested, liquid formula that provides complete nutrition while effectively starving the bacteria — offers another option. It requires strict adherence for two to three weeks and can produce significant symptom improvement, though it is not easy to follow and is best undertaken with professional support. (Rezaie et al. 2025)(Rezaie et al. 2025)
Dietary approaches: supporting treatment with a low fermentable diet
Dietary modification is not a standalone SIBO treatment, but practitioners frequently use it alongside antimicrobial or antibiotic protocols to help manage symptoms during the treatment phase and reduce the substrate available to feed the overgrowth.
The most evidence-supported dietary approach in this context is a low-FODMAP diet — which limits fermentable oligosaccharides, disaccharides, monosaccharides and polyols, reducing gas production and symptom burden during treatment. (Bogdanowska-Charkiewicz et al. 2026) Other dietary frameworks are used in functional medicine clinical practice, including the Specific Carbohydrate Diet (SCD) and the SIBO Bi-Phasic Diet, though robust clinical trial evidence for these specifically in SIBO remains limited. Clinical presentation, practitioner experience, and individual tolerance generally guide approach selection.
Whichever approach is used, these are intended as short-term therapeutic tools, not long-term eating patterns. Prolonged restriction without supervision carries real risks, including reduced dietary diversity, nutritional deficiencies particularly in fibre, B vitamins and certain minerals, and an increasingly difficult relationship with food.
Practitioners strongly recommend professional supervision before embarking on any SIBO-specific dietary protocol, both to ensure the approach suits your type and symptom pattern, and to support safe, structured reintroduction once treatment is complete.
How do I know which SIBO treatment is right for me?
There is no one-size-fits-all answer to this. The most appropriate treatment depends on several factors:
Your SIBO type
SIBO is not a single, uniform condition. Breath testing can identify three distinct types based on the gas the organisms produce, and each tends to present differently:
- Hydrogen-dominant SIBO — the most common type, typically associated with diarrhoea, loose stools, or mixed bowel habits, alongside bloating and abdominal discomfort (Quigley et al. 2020)
- Hydrogen sulphide-dominant SIBO — UK breath testing does not currently measure hydrogen sulphide (H2S). However, clinicians can suspect it when a breath test returns a ‘flatline’ result — meaning no significant elevations in either hydrogen or methane — alongside symptoms characteristic of H2S dominance, including diarrhoea, strong sulphur odour to flatulence, tingling or numbness in the extremities, and heightened sensory sensitivity. In these cases, the clinical picture guides the treatment approach rather than a confirmed test result (Banik et al. 2016; Lim & Rezaie 2023)
- Methane-dominant overgrowth — associated primarily with constipation and slower gut transit; technically now classified separately as Intestinal Methanogen Overgrowth (IMO), because the organisms responsible are archaea rather than bacteria. Despite this distinction, clinicians still commonly group it under the SIBO umbrella and treat it within the same clinical framework (Quigley et al. 2020)
Understanding which type, or combination of types, you have matters significantly for treatment selection, as the most effective antimicrobial protocols differ between them.
Symptom severity and history
Someone with mild-to-moderate symptoms and a first-time diagnosis may respond well to a single round of herbal antimicrobials. Someone with a longer history, multiple previous treatments, or significant underlying health conditions may need a more phased approach.
Underlying drivers
Identifying the underlying cause is arguably more important than the antimicrobial choice itself.(Ahmed et al. 2023) Common drivers include:
- Impaired migrating motor complex (MMC) — the ‘housekeeping wave’ that sweeps bacteria along thus preventing overgrowth
- Low stomach acid (caused by PPI use, for example) or pancreatic enzyme insufficiency
- History of gastroenteritis or food poisoning (post-infectious SIBO)
- Structural issues such as adhesions or strictures
- Underlying conditions including hypothyroidism, coeliac disease, or connective tissue disorders
- Chronic stress and autonomic nervous system dysregulation
A thorough case review, including health history, symptom pattern, previous investigations and lifestyle factors, forms the foundation of any well-reasoned SIBO treatment plan. This is exactly what our initial consultation process is designed to establish.
What happens if SIBO comes back?
SIBO recurrence is one of the most frustrating aspects of this condition, and unfortunately, it’s common. Studies suggest recurrence rates of approximately 43% within 10 months of treatment when underlying causes are not addressed.(Ahmed et al. 2023) If SIBO keeps returning for you, this is a signal that something hasn’t been fully resolved rather than a sign that treatment can’t work.
Common reasons SIBO recurs
- The underlying cause was not identified or addressed
- Treatment duration was too short, or the antimicrobial was not the right match for your SIBO type
- The migrating motor complex (MMC) remains impaired — motility support was not included
- Reintroduction of foods or habits that perpetuate the overgrowth
- Structural issues that haven’t been investigated or managed
What to do if SIBO returns
If SIBO has returned — especially if it has returned more than once — it’s worth working with a specialist practitioner to go deeper into the ‘why’. This might mean:
- Retesting to confirm overgrowth and identify current type
- A more thorough investigation of underlying drivers, including stool testing, thyroid function, or other relevant investigations
- Adding motility agents (prokinetics) to support the MMC between treatment rounds
- A different antimicrobial protocol or combination approach
- Addressing gut-brain axis and nervous system regulation as part of a broader plan
Persistent SIBO is manageable. With the right level of investigation and a comprehensive plan, most people do find a way through — it simply requires a more thorough approach than a single course of antimicrobials.
How we approach SIBO treatment at IBS & SIBO Clinics
We are a team of fully qualified nutritional therapists and certified functional medicine practitioners with over 25 years of combined experience in digestive health. SIBO is our specialism, it is what we do, every day, for clients across the UK and internationally.
Our approach is built on the understanding that SIBO is rarely a simple or isolated problem. We take a thorough, root-cause approach that looks beyond the overgrowth to understand the full clinical picture.
Our SIBO treatment process
Every client journey begins with a detailed case review. Before your first consultation, we review your questionnaire and any existing test results so that we can use our time together as efficiently as possible.
In your initial consultation (60–90 minutes), we build a detailed clinical timeline, drawing on your medical and family history, symptom pattern, diet, lifestyle, stress history and any relevant investigations, to identify the likely drivers of your SIBO and develop a personalised treatment plan.
Depending on your situation, this plan may include:
- A targeted antimicrobial protocol (herbal or pharmaceutical, based on your case)
- Motility support to protect against recurrence
- Dietary guidance tailored to your SIBO type and tolerance (which may or may not include a low-FODMAP or specific carbohydrate approach)
- Gut-healing support to restore the intestinal environment
- SIBO breath testing or re-testing if not already completed
- Addressing nutritional deficiencies commonly associated with SIBO (B12, iron, fat-soluble vitamins)
We work with you over multiple follow-up sessions, adjusting the plan as your symptoms evolve and test results come in.
We’ve helped thousands of people with SIBO. If you’re ready to take a more thorough approach, we’d love to help.
Frequently asked questions about SIBO treatment
Can SIBO be cured permanently?
SIBO can be successfully treated and many people remain symptom-free long-term. The key is addressing the underlying factors that predisposed you to SIBO in the first place. Without this, recurrence is common — but with a comprehensive approach, lasting resolution is absolutely achievable.
Is SIBO treatment available on the NHS?
SIBO is not widely recognised or treated within the NHS. While some gastroenterologists may prescribe rifaximin privately, most SIBO treatment in the UK takes place in private practice. Nutritional therapy and functional medicine practitioners work with herbal protocols and provide comprehensive lifestyle and dietary support alongside any antimicrobial treatment.
How long does SIBO treatment take?
A typical course of herbal antimicrobials runs four to six weeks. Pharmaceutical antibiotic courses are usually ten to fourteen days. However, the overall treatment journey — including addressing underlying causes, supporting gut healing, and rebuilding a healthy microbiome — typically spans three to six months, with follow-up as needed.
Do I need a SIBO breath test before starting treatment?
A breath test is helpful to confirm a SIBO diagnosis and identify which type you have (hydrogen, methane, or hydrogen sulphide), as this influences the most appropriate treatment approach. That said, breath tests are not infallible, and an experienced practitioner can sometimes make clinical decisions based on symptoms and history alongside or in place of testing. We offer SIBO breath testing and can advise on the most appropriate testing route for your situation.
Can diet alone treat SIBO?
Diet can significantly reduce SIBO symptoms and help create a less favourable environment for bacterial overgrowth, but it is unlikely to resolve SIBO on its own. Antimicrobial treatment is generally needed to meaningfully reduce the overgrowth. Diet is most powerful as a complement to antimicrobial treatment and as a long-term strategy for reducing recurrence risk.
References:
Ahmed, J.F., Padam, P. and Ruban, A. (2023) ‘Aetiology, diagnosis and management of small intestinal bacterial overgrowth’, Frontline Gastroenterology, 14(2), pp. 149–154.
Banik, G.D., De, A., Som, S., et al. (2016) ‘Hydrogen sulphide in exhaled breath: a potential biomarker for small intestinal bacterial overgrowth in IBS’, Journal of Breath Research, 10(2), p. 026010.
Bogdanowska-Charkiewicz, D. et al. (2026) ‘Effectiveness of the low FODMAP diet in patients with irritable bowel syndrome and small intestine bacterial overgrowth syndrome’, Frontiers in Nutrition, 13, p. 1725524.
Bushyhead, D. and Quigley, E.M.M. (2022) ‘Small intestinal bacterial overgrowth — pathophysiology and its implications for definition and management’, Gastroenterology, 163(3), pp. 593–607.
Chedid, V., Dhalla, S., Clarke, J.O., et al. (2014) ‘Herbal therapy is equivalent to rifaximin for the treatment of small intestinal bacterial overgrowth’, Global Advances in Health and Medicine, 3(3), pp. 16–24.
Lim, J. and Rezaie, A. (2023) ‘Pros and cons of breath testing for small intestinal bacterial overgrowth and intestinal methanogen overgrowth’, Gastroenterology & Hepatology, 19(3), pp. 140–146.
Nickles, M.A., Hasan, A., Shakhbazova, A., et al. (2021) ‘Alternative treatment approaches to small intestinal bacterial overgrowth: a systematic review’, Journal of Alternative and Complementary Medicine, 27(2), pp. 108–119.
Quigley, E.M.M., Murray, J.A. and Pimental, M. (2020). ‘AGA Clinical Practice Update on Small Intestinal Bacterial Overgrowth: Expert Review’, Gastroenterology Clinical Practice Guidelines, 159(4), pp. 1526-1532.
Rezaie, A., Chang, B.W., de Freitas Germano, J., et al. (2025). ‘Effect, Tolerability, and Safety of Exclusive Palatable Elemental Diet in Patients With Intestinal Microbial Overgrowth’, Clinical Gastroenterology and Hepatology, 23(12), pp. 2306-2317.e7
Sachdev, A.H. and Pimentel, M. (2013) ‘Gastrointestinal bacterial overgrowth: pathogenesis and clinical significance’, Therapeutic Advances in Chronic Disease, 4(5), pp. 223–231.
