SIBO Treatment: Testing, Diet, Supplements and Finding the Root Cause
Bloating that appears after almost every meal, changes in bowel movements, excessive gas, abdominal discomfort, or the feeling that almost everything you eat leaves you uncomfortable?
If you’ve been trying to understand ongoing digestive symptoms, you may have come across SIBO, Small Intestinal Bacterial Overgrowth.
SIBO has become a common topic in the gut health space, but the conversation is often reduced to a simple formula: Too much bacteria ->kill the bacteria = problem solved.
The reality is considerably more nuanced.
SIBO is not simply about having too much bacteria. It is about what is happening within the small intestine, microbial activity, gastrointestinal motility, digestion and the factors that may have allowed an altered microbial environment to develop in the first place.
And that distinction matters when it comes to treatment.
What is SIBO?
SIBO refers to an abnormal amount or type of microorganism within the small intestine, where microbial numbers are normally much lower than in the large intestine.
These microorganisms can ferment carbohydrates and produce gases, including hydrogen and methane. This fermentation can contribute to symptoms such as:
· Bloating and abdominal distension
· Excessive gas
· Abdominal discomfort or pain
· Diarrhoea
· Constipation
· Alternating bowel habits
· Feeling overly full after meals
· Changes in digestion
· Nutrient deficiencies or malabsorption in some cases
But there is an important distinction to make.
Bloating doesn’t automatically mean SIBO
These symptoms can also occur with IBS, coeliac disease, inflammatory bowel disease, constipation, pelvic floor dysfunction, motility disorders and other gastrointestinal conditions.
This is why symptoms alone aren’t enough to determine whether SIBO is present. The first step is understanding the pattern.
How is SIBO tested?
There isn’t one test that tells us everything about the gastrointestinal tract. This is why I like to consider both targeted and the broader digestive picture.
Hydrogen and methane breath testing
Hydrogen and methane breath testing is one of the commonly used non-invasive approaches for investigating SIBO and intestinal methanogen overgrowth.
During the test, a carbohydrate substrate is consumed, and breath samples are collected at regular intervals. These samples are analysed for gases produced by microorganisms as the substrate moves through the gastrointestinal tract.
Breath testing has limitations, so results are best interpreted alongside symptoms, medical history and the broader clinical picture.
Complete Microbiome Mapping
I also like to look beyond SIBO itself.
Complete microbiome mapping doesn’t diagnose SIBO however it can provide a broader picture of the gastrointestinal microbial environment and, depending on the test, additional functional markers.
So rather than relying on one result in isolation, the aim is to bring together symptoms, history and testing information to understand what’s happening across the digestive system.
Why did the overgrowth develop?
This is the question that I think gets missed most often.
A positive SIBO or IMO result tells us something about the current gastrointestinal environment. It doesn’t necessarily tell us why it happened.
Factors worth considering include:
· Gastrointestinal motility and constipation
· Previous gastrointestinal infection
· Previous abdominal surgery
· Digestive function
· Certain medication
· Gastric acid suppression
· Pancreatic or biliary function
· Underlying gastrointestinal disease
· Dietary and meal patterns
For example, methane associated overgrowth, and constipation can exist in a cycle where slower intestinal transit creates an environment that favours methane production, while methane itself is associated with slow transit.
Similarly, gastric acid is part of the body’s defence against microorganisms entering through the gastrointestinal tract. A meta-analysis of 19 studies involving 7,055 people found that proton pump inhibitor (PPI) use was associated with an increased risk of SIBO.
This doesn’t mean PPIs are inherently bad or that prescribed medication should be stopped. It simply highlights why digestion and medication history can be relevant pieces of the puzzle.
From a naturopathic perspective, digestive support may include things such as bitter herbs or foods before meals, thorough chewing, meal timing or digestive enzyme support where clinically appropriate.
What about Diet?
A low FODMAP diet can be incredibly useful for reducing digestive symptoms.
FODMAPS are fermentable carbohydrates, therefore reducing them can decrease fermentation and improve symptoms such as bloating and gas for some people.
But symptom improvement isn’t necessarily the same as addressing the underlying problem.
A systematic review and meta-analysis of nine trials involving 403 people with IBS found that a low FODMAP diet consistently reduced bifidobacteria.
This doesn’t mean low FODMAP is bad, it means that prolonged restriction shouldn’t automatically become the end goal.
What about supplements and herbal medicine?
This is where the evidence gets particularly interesting and where online advice becomes very black and white.
A 2014 study compared herbal therapy with rifaximin in people with positive lactulose breath tests. Among participants who completed follow-up testing, 46% of those receiving herbal therapy had a negative follow-up breath test compared with 34% receiving rifaximin.
Most recently, a randomised clinical trial involving 179 people investigated adding herbal supplements, probiotics and prebiotics to antibiotic treatment and dietary modification.
The additional intervention was associated with higher rates of clinical remission, partially in methane-associated cases, although it did not significantly reduce gas concentrations compared with standard treatment.
Depending on the presentation, treatment may include antimicrobial herbs, digestive support, nutritional support or motility focused interventions.
The combination, dose, duration and sequencing all matter.
Probiotics?
This is another area where SIBO advice tends to become very black and white online.
Some say ‘never take probiotics if you have SIBO’ others say ‘everyone with SIBO needs probiotics’.
Neither tells the whole story so let’s look further
Different strains have different properties, and evidence for probiotics specifically in SIBO remains limited and inconsistent.
Sometimes microbial support may be useful. Sometimes it may not be the priority.
The more important question is what this person’s digestive system needs at this point in treatment.
So what does treatment actually look like?
There isn’t one universal SIBO protocol.
Depending on the individual, treatment may involve:
Identifying the pattern – Hydrogen, methane, IMO, mixed?
Understanding the contributing factors – Motility, constipation, digestion, medications, previous infection, diet and medical history.
Addressing the overgrowth – where appropriate, this may involve medical antibiotic treatment, herbal medicine or another clinically relevant approach.
Supporting digestion and motility – particularly where constipation or impaired digestive function is part of the presentation.
Using diet strategically – reducing symptoms without creating unnecessary long-term restriction.
Supporting the broader gut environment – including nutritional adequacy and dietary diversity.
And importantly, addressing the factors that may contribute to recurrence.
The bigger picture
SIBO isn’t simply a problem of ‘too much bacteria’, it can involves microbial activity, motility, digestion, gastric function, diet, medication and the broader gastrointestinal environment.
If you’ve been stuck in the cycle of eliminating foods, trying supplements and still not understanding why your gut isn’t behaving normally, you may not need another generic SIBO protocol.
You may need a clearer picture of what’s actually happening.
At Thryve Naturopathy, we take a testing let approach to gut health, combining your symptoms and history with appropriate functional testing to build a treatment plan around you, rather than simply treating a label.
Ready to get to the bottom of your gut symptoms? Book a consultation with Thryve today.
References
Chedid, Victor, et al. “Herbal Therapy Is Equivalent to Rifaximin for the Treatment of Small Intestinal Bacterial Overgrowth.” Global Advances in Health and Medicine, vol. 3, no. 3, May 2014, pp. 16–24, 10.7453/gahmj.2014.019.
Liu, Yingying, et al. “Effect of the Combined Intervention of <Scp>Low‐FODMAPs</Scp> Diet and Probiotics on <Scp>IBS</Scp> Symptoms in Western China: A Randomized Controlled Trial.” Food Science & Nutrition, 29 Feb. 2024, 10.1002/fsn3.4057.
Redondo-Cuevas, Lucia, et al. “Do Herbal Supplements and Probiotics Complement Antibiotics and Diet in the Management of SIBO? A Randomized Clinical Trial.” Nutrients, vol. 16, no. 7, 1 Jan. 2024, p. 1083, https://www.mdpi.com/2072-6643/16/7/1083, 10.3390/nu16071083. Accessed 11 Aug. 2026.
Su, Tingting, et al. “Meta-Analysis: Proton Pump Inhibitors Moderately Increase the Risk of Small Intestinal Bacterial Overgrowth.” Journal of Gastroenterology, vol. 53, no. 1, 2 Aug. 2017, pp. 27–36, 10.1007/s00535-017-1371-9.