For a long time, SIBO remained a grey area of digestive practice, often confused with other functional disorders.
But since 2023, its inclusion in the WHO’s ICD codes has changed things: SIBO is now recognised as a clinical entity in its own right1.
In this Simplycure webinar, Christian Boyer, a doctor of biology, nutritionist and practitioner specialising in digestive and hormonal disorders, sets out 5 clear pillars for improving the diagnosis and management of SIBO.
The aim: to help you build SIBO into your clinical reflexes and everyday protocols.
Pillar 1: identifying the type of SIBO
From the outset, Christian Boyer stresses: “To win a war, you need to know your enemy well”.
SIBO, literally “small intestinal bacterial overgrowth”, is a bacterial dysbiosis, not an infection. The bacteria involved are commensal bacteria (known as pathobionts) that become harmful when they proliferate.
This overgrowth develops in the small intestine, an area that is normally low in bacteria and devoted to absorption rather than fermentation. This qualitative and quantitative imbalance is what explains the typical digestive symptoms: gas, bloating, pain and transit disorders.
Since 2023, SIBO has indeed been recognised by the WHO in the ICD codes, which reinforces its clinical legitimacy.
Three main configurations need to be distinguished, characterised by breath tests:
TypeGas producedDominant symptomsDistinguishing featuresHydrogen SIBOHydrogenRapid bloating after carbohydrate-rich meals, frequent diarrhoeaMost common presentationIMO (Intestinal Methanogen Overgrowth)MethaneMarked constipation, diffuse painVery sluggish transit, frequent relapsesISO (Intestinal Sulfide Overproduction)SulphidesSevere bloating, urgent diarrhoea or alternating with constipationStrong odour, increased inflammation
Key point: clinical signs alone are not enough. Diagnosis relies on breath tests (glucose or lactulose), which identify the nature of the overgrowth and allow care to be tailored.
Pillar 2: identifying the causes of SIBO
SIBO is never an isolated condition2. It is always the consequence of an underlying terrain or a triggering factor. For Dr Boyer, identifying the cause is an essential step, without which the patient risks relapsing quickly after treatment.
The 4 main categories of causes of SIBO
CategoryClinical examplesPossible consequencesIntestinal dysmotilityFood poisoning, hypothyroidism, diabetes, Parkinson’sSlower transit, stagnation of the food bolus, excessive fermentationSecretion deficitsHypochlorhydria, pancreatic enzyme deficiency, bile insufficiencyPoor digestion, bacterial proliferationIatrogenic factors / surgeryAdhesions, intestinal resection, bariatric surgeryStasis and areas of bacterial overgrowthMedication & lifestylePPIs, opioids, antibiotics, chronic stressDisruption of the microbiota and peristalsis
Identifying the cause of SIBO is therefore a key step: without this work, care remains incomplete and relapse is almost inevitable. A precise assessment of the patient’s terrain makes it possible to target the therapeutic intervention and place treatment within a lasting strategy.
Pillar 3: adapting the diet to the configuration
Diet is a powerful lever for relieving symptoms and limiting fermentation. But for Christian Boyer, it must be personalised and should never be reduced to prolonged restrictive diets.
Biphasic diet: a reduction phase followed by a phase of gradual reintroduction.
Low FODMAP approach: useful for some patients, but not universal.
Low sulfur diet: suited to H₂S SIBO (ISO), limiting foods rich in sulphur compounds.
Spacing between meals: 4 to 5 hours between meals to stimulate the migrating motor complex and reduce stagnation3.
Key point: diet is a supportive therapeutic tool. It must be adapted to the identified gas profile and remain transitional, ahead of a gradual reintroduction.
Pillar 4: micronutritional management
Beyond diet, managing SIBO also means working with micronutrition. As Christian Boyer reminds us: “it is not an infection to eradicate, it is a balance to restore.” The aim is therefore to support digestion, reduce overgrowth and prevent stagnation.
GoalPossible approachesPoints to watchSupport digestive function• Restore gastric acidity if hypochlorhydria
• Provide pancreatic enzymes and bile salts
• Use bitter herbs to stimulate secretionsCaution in patients on PPIs or those who are frail (acidity, bile)Reduce bacterial load• Conventional antibiotics (rifaximin, neomycin)
• Natural antimicrobials (oregano, garlic, berberine, neem, caprylic acid)
• Elemental diet (a specific, transitional option)Tailor to the profile, risk of relapse if the cause is not treatedPrevent stagnation / support motility• Natural or pharmaceutical prokinetics to maintain intestinal emptyingEssential to prevent recurrence
In practice, micronutrition is therefore a central lever for supporting the patient beyond mere symptom relief.
Pillar 5: avoiding relapse
Treating SIBO without preventing recurrence means risking seeing the same patient again a few months later with the same symptoms4. For Christian Boyer, relapse prevention must be planned from the very start of care.
Three areas are essential:
Consolidate the identified cause: whether this involves a motility disorder, hypochlorhydria or post-surgical adhesions, care must target the underlying terrain.
Support digestive motility: using prokinetics (natural or pharmaceutical) is a key step in avoiding stagnation of the food bolus and preventing a fresh overgrowth.
Reintroduce foods gradually: after a phase of tailored diet, it is crucial to reaccustom the microbiota gently, restoring bacterial diversity without triggering excessive fermentation again.
Relapse prevention is not a “bonus” but a central component of the protocol. It determines the durability of results and long-term patient satisfaction.
Conclusion: a comprehensive strategy to avoid the vicious circle of SIBO
SIBO is not a “simple” bacterial overgrowth to eradicate, but a complex imbalance that often reflects an underlying cause.
As Christian Boyer reminded us, the effectiveness of care rests on a comprehensive approach: identifying the type of SIBO through reliable tests, investigating the causes, adapting the diet, supporting digestive function and preventing relapse. It is by bringing these five pillars together that you can genuinely offer your patients lasting improvement, far from exhausting cycles of relapse.
To find out more about SIBO support, contact the Simplycure team today!
