Why SIBO Breath Tests Are Fundamentally Unreliable: And How to Actually Identify What's Happening in Your Gut

The Problem Nobody Wants to Say Out Loud

You took a SIBO breath test. Maybe you tested positive and started antibiotics, herbals, or a restrictive diet. Maybe you tested negative and were told you don’t have SIBO, so your symptoms must be IBS, anxiety, or something else entirely. Either way, you’re still bloated. You’re still gassy. Your digestion is still broken.

Here’s what most people don’t understand: the breath test wasn’t designed to diagnose what’s actually happening in your gut. It was designed to measure something much narrower. The gap between what it measures and what you actually have is where the real problem lives.

This is not conspiracy. This is mechanics. And once you understand the mechanics, you’ll see why these tests fail not occasionally but systematically. More importantly, you’ll understand how to gather real data about what’s actually happening in your small intestine.

Part 1: Why SIBO Breath Tests Fail—The Mechanistic Reality

What the Breath Test Actually Measures

A SIBO breath test measures one thing: the concentration of hydrogen and methane gases you exhale over 3 hours after drinking a substrate solution, usually lactulose or glucose.

What it’s supposed to tell you is whether you have bacterial overgrowth in your small intestine. What it actually tells you is whether measurable quantities of hydrogen and methane appeared in your breath during those three hours, under those specific conditions.

These are not the same thing. The distance between them is where thousands of people fall through the cracks.

The First Problem: Bacterial Diversity and Gas Production Heterogeneity

Most SIBO explanations skip a critical point: not all bacteria produce hydrogen or methane in equal amounts. Many don’t produce these gases at all under the substrate conditions used in the test.

The small intestine can be colonized by hundreds of bacterial species. The classical SIBO narrative focuses on Methanobrevibacter smithii, which produces methane, and various hydrogen-producing bacteria like Klebsiella and Clostridia. But this oversimplifies reality.

The actual microbial communities that overgrow in a compromised small intestine are far more diverse and metabolically heterogeneous than the simple hydrogen plus methane model suggests. When you ingest the test substrate, whether lactulose or glucose, the test assumes bacteria will ferment it efficiently into measurable gas.

But this assumption is wrong. A dysbiotic small intestinal ecosystem might contain facultative anaerobes that primarily consume oxygen, sulfate-reducing bacteria that produce hydrogen sulfide rather than hydrogen or methane (making them invisible to the breath test), acetogenic bacteria that consume hydrogen and use it to produce acetate rather than release it, methanogenic archaea that are metabolically suppressed due to local chemical conditions, and non-fermentative bacteria that utilize amino acids, lipids, or bile acids rather than the carbohydrate substrate in the test.

In other words, you can have a severely dysbiotic small intestine with profound dysfunction while the breath test comes back negative. The dominant bacteria in your gut simply aren’t the ones that efficiently ferment lactulose into hydrogen or methane under test conditions. This is not rare anymore. As dysbiosis patterns become more complex, this scenario is increasingly common.

The Second Problem: Transit Time Variability and the Timing Window Trap

The SIBO breath test assumes something that is almost never true: that the substrate reaches your small intestine at a predictable time and stays there long enough for bacteria to ferment it.

Here’s why this matters. Normal small bowel transit time is 20 to 40 minutes. Anything faster is considered rapid transit. The breath test typically measures for 120 to 180 minutes after substrate ingestion, with samples every 20 minutes.

The test is looking for a rise in hydrogen or methane in your breath that appears within this window. The underlying assumption is a chain of events: substrate is ingested, travels through the stomach which varies wildly based on meal composition and autonomic state, reaches the small intestine, bacteria ferment it, gas crosses the intestinal wall, the gas is absorbed into the bloodstream, travels through the capillary network, crosses the alveolar-capillary membrane in your lungs, and finally you exhale it.

Any disruption at any step makes the test unreliable.

The real problem is this: people with dysbiosis and compromised small intestinal barrier function often have dysregulated motility. This can mean rapid transit where the substrate shoots through the small intestine before bacteria have time to ferment it significantly. The test comes back negative, but bacteria are still there. They just didn’t encounter your test substrate in time.

Or it can mean slow transit where the substrate finally reaches bacteria 90 minutes in, they start fermenting, but you’re already 2 hours into the test window and the reading is declining. The substrate might reach the colon before bacteria fully digest it, never producing a characteristic small intestine peak.

Or it can mean segmental dysfunction where different regions of your small intestine have different transit rates. Bacteria might be in one region while your substrate is in another, and they never meet during the test window.

People with IBS, dysbiosis, long COVID, post-viral syndrome, or mast cell activation disorder almost always have dysregulated motility. The breath test was designed assuming normal motility. It fails systematically when motility is abnormal, which is precisely when you’re most likely to actually have SIBO.

The Third Problem: The Substrate Problem

The standard SIBO breath test uses one of two substrates: lactulose or glucose. These are not interchangeable, and neither one accurately reflects what bacteria in your small intestine are actually fermenting.

Lactulose is a synthetic disaccharide not naturally found in food. Your human digestive enzymes can’t break it down, so it reaches the small intestine intact. If bacteria there ferment it, you’ll see gas. But lactulose is a selective substrate. It preferentially feeds certain bacteria, particularly Bifidobacteria and some Bacteroides species.

If your dysbiosis is dominated by different bacteria, lactulose will give you a falsely negative result. Moreover, lactulose is osmotically active. It pulls water into the intestinal lumen and can trigger osmotic diarrhea in the test window. This can actually flush out bacteria before they ferment the substrate, giving you a false negative.

Glucose is more physiologically relevant since it’s a normal food component. But it’s also more problematic for SIBO testing specifically. Glucose is readily absorbed in the proximal small intestine under normal conditions. Very little makes it past the duodenum and jejunum. If your small intestine is functioning normally, bacteria don’t see much glucose. They only see it if you have rapid transit, severely compromised absorptive capacity, or bacteria have colonized the duodenum and proximal jejunum.

So a negative glucose breath test might just mean your dysbiosis isn’t severe enough to prevent glucose absorption, not that you don’t have bacterial overgrowth.

Meanwhile, in real life, bacteria in your small intestine are fermenting resistant starch, fiber, oligosaccharides, amino acids, bile acids, mucus glycoproteins, and sloughed epithelial cells. None of these are measured by the breath test. You could have thriving bacterial colonies fermenting your actual food, producing copious gas from your actual diet, while the breath test substrate never reaches them or they can’t ferment it efficiently.

The Fourth Problem: Absorption and Excretion Variables

Here’s something almost never discussed in SIBO patient communities. Hydrogen and methane don’t simply appear in your breath because bacteria produced them. They must cross the intestinal wall, survive in the bloodstream, reach the lungs, cross the alveolar-capillary membrane, and be exhaled in sufficient concentration to measure.

Each of these steps introduces variability that has nothing to do with whether bacteria are actually in your small intestine.

Consider these scenarios: People with compromised intestinal barrier function might absorb more gas across the barrier due to increased permeability, creating a false positive. People with portal hypertension or hepatic dysfunction might absorb gas normally but not transport it efficiently to the lungs, causing a false negative.

People with respiratory dysfunction or chronic hyperventilation might not exhale gas efficiently even if it’s in their bloodstream. People with anemia or iron dysmetabolism might have altered gas-carrying capacity.

The breath test assumes a healthy respiratory, circulatory, and barrier system. People with dysbiosis often have none of these. The test becomes a proxy not just for small intestinal bacteria but for your entire integrated physiology.

The Fifth Problem: Hydrogen Sulfide and Other Non-Measured Gases

Here’s a critical issue that breath tests completely miss: hydrogen sulfide is a major product of dysbiotic fermentation, and it is completely invisible to standard breath testing.

Hydrogen sulfide is highly soluble in blood, unlike hydrogen which is barely soluble. It’s rapidly metabolized in the bloodstream and tissues through sulfide oxidation pathways. It’s strongly protein-bound, attaching to hemoglobin, myoglobin, and other proteins. It’s neurotoxic and potent even in tiny concentrations.

Hydrogen sulfide is produced abundantly by sulfate-reducing bacteria like Desulfovibrio and Desulfobacter. These bacteria are increasingly prevalent in dysbiotic guts, especially in people with chronic fatigue syndrome, long COVID, mold exposure, post-antibiotic dysbiosis, and high-stress backgrounds.

If your dysbiosis is dominated by hydrogen sulfide producers, you will have a negative or low-positive breath test because most of the gas being produced is hydrogen sulfide, not hydrogen or methane. But you’ll experience severe neurological symptoms including brain fog, headache, and cognitive dysfunction. You’ll have severe GI symptoms including cramping, urgency, and mucus stools. You’ll have fatigue and post-exertional malaise and immune activation including elevated mast cell mediators.

The breath test will tell you that you don’t have SIBO. The reality will tell you that you have a devastating dysbiosis powered by hydrogen sulfide-producing bacteria, and you need an entirely different diagnostic and treatment approach.

The Sixth Problem: The Timing of Symptom Onset vs. Breath Peak

Here’s something that reveals the fundamental flaw: people with actual small intestinal dysbiosis often experience bloating and gas within 30 to 45 minutes of eating a problematic meal. But the SIBO breath test is looking for a rise in hydrogen or methane that appears within 2 to 3 hours after ingesting a specific substrate under controlled conditions.

If you have severe dysbiosis with rapid gas production, you should see symptoms appear when bacteria encounter the substrate. Your symptoms should correlate with the breath measurements. But they often don’t.

Why? Because you’re in a controlled lab setting with less stress. You’ve fasted beforehand, which changes your microbiome composition and fermentation patterns. You’re not eating other foods, so bacteria aren’t competing for substrates. You’re not moving your gut, which stimulates motility and gas emission. Your symptom response to gas is suppressed because it’s an artificial scenario.

People frequently report that their symptoms are much worse at home than they were during the breath test. They say they always bloat after eating, but the breath test was negative. This is not because the breath test is occasionally inaccurate. It’s because the breath test measures something that bears an uncertain relationship to your actual symptom-producing dysbiosis.

The Seventh Problem: What the Thresholds Actually Represent

The SIBO breath test diagnosis relies on specific cutoff thresholds. Classic interpretation uses hydrogen above 20 ppm or methane above 10 ppm. Some labs use hydrogen above 12 ppm. Others use combined hydrogen plus methane above 15 ppm.

These thresholds were derived from studies comparing small populations of healthy controls versus small populations of patients with defined SIBO. The problem is that these studies were done in academic medical centers on relatively homogeneous populations, often excluding people with significant comorbidities.

But the people taking SIBO breath tests today are post-antibiotic dysbiosis patients, long COVID patients, people with MCAS or EDS or other systemic conditions, and people with stress-induced or medication-induced dysbiosis. These populations likely have different baseline breath measurements and different relationships between breath gas and symptoms than the reference populations used to set the thresholds.

Moreover, the threshold is a population threshold, not an individual one. Just because healthy people on average have less than 20 ppm hydrogen doesn’t mean your normal baseline is less than 20 ppm. You might be a natural hydrogen producer or a naturally low producer. The test doesn’t tell you your individual baseline; it compares you to a population average.

Part 2: How to Actually Identify What’s Happening

The breath test is unreliable. So what do you do?

You gather real, mechanistic data about your own gut using methods that correlate directly with your symptoms and your actual physiology.

The Foundation: Symptom-Timing Mapping

Before anything else, you need to understand the temporal relationship between eating and your symptoms.

For 2 to 4 weeks, track the following:

Immediately upon eating (0 to 5 minutes), note whether you feel immediate bloating or distension in your upper abdomen, whether you feel a warm or reactive sensation in your GI tract, and whether your appetite disappears even though you just started eating. These suggest rapid fermentation, possibly with bacterial overgrowth in the upper small intestine or proximal duodenum.

Between 15 to 45 minutes after eating, track when bloating typically peaks, whether it’s localized (right upper quadrant, epigastrium, left lower quadrant) or diffuse, whether you feel pain versus distension versus pressure versus bloating, whether you have an urge to defecate or pass gas, and whether you burp and if so how many times and whether the burps smell putrid, sulfurous, or neutral. Peak bloating in this window suggests small intestinal fermentation, likely from dysbiosis in the jejunum.

Between 2 to 4 hours after eating, note whether bloating continues or worsens, whether it shifts location from upper to lower abdomen, whether you pass gas and how much and what the smell is, and whether you have urgency for defecation. This window suggests colonic fermentation or delayed small intestinal transit.

At 4 or more hours after eating, note whether you’re still bloated from that meal, whether symptoms improve after passing stool, and whether symptoms improve after passing gas. This indicates significant dysbiosis or reduced absorptive capacity.

Key pattern recognition: Rapid onset (0 to 15 minutes) plus rapid resolution (within 2 hours) suggests likely upper small intestinal dysbiosis. Delayed onset (1 to 3 hours) plus sustained symptoms suggests likely jejunal or ileal dysbiosis or slow transit. Worsening after 2 to 3 hours suggests colonic involvement or very slow transit. Symptoms that don’t resolve with gas passage suggest possibly not dysbiosis-driven issues; could be malabsorption, inflammation, or barrier dysfunction.

The Substrate Challenge Test: Self-Directed Fermentation Mapping

Since the standard breath test uses artificial substrates, you’re going to test your own small intestine using actual foods and track what happens.

The principle is simple: different foods will provoke different symptom responses depending on what bacteria are fermenting them and what gas they produce.

Your toolkit includes H2S-sensitive test strips, which you can buy online as chemistry lab supplies for around $15 to $30 per pack. You will breathe into a bag and test your breath for hydrogen sulfide. This is crude but informative. You’ll also need a food diary with precise timing and symptom logging and a transit marker.

Test these challenge foods individually, 2 to 3 days apart, in controlled settings (morning, fasted, at home where you can monitor):

For high resistant starch foods that feed butyrate producers and hydrogen producers, try cooled white rice (1 cup), green banana (1 medium), or cooked potato (1 medium, cooled).

For high fructose and oligosaccharide foods that feed dysbiotic gas producers, try apple (1 medium), onion (1/2 cup raw), wheat bread (2 slices), or garlic (2 cloves).

For high sulfur compound foods that feed hydrogen sulfide producers, try egg (1 whole), cruciferous vegetables like broccoli (1 cup) or cabbage (1 cup raw), garlic (2 cloves), or chicken or beef (4 ounces).

For pure sugar with minimal substrate competition, try white sugar (2 tablespoons mixed in water) or pure glucose (1 tablespoon, if you can get it).

For each challenge, consume food on an empty stomach with plain water at hour zero. Log every 15 minutes from hour 0 to 4: bloating severity (0 to 10 scale), bloating location, gas (yes or no, frequency, odor), bowel urge (yes or no, urgency level), burps (yes or no, count, smell), abdominal pain or cramping, neurological symptoms (brain fog, headache, mood change), skin responses (flushing, itching), and other symptoms.

From hour 4 to 24, note whether symptoms resolve or persist.

Pattern interpretation: Rapid, severe response to resistant starch suggests hydrogen-producing bacteria in upper small intestine. Severe response to fructose and oligosaccharides suggests dysbiotic fermenters (likely dysbiosis, not normal). Severe response to sulfur compounds suggests hydrogen sulfide producers (possibly sulfate-reducing bacteria overgrowth). Severe response to protein suggests proteolytic bacteria overgrowth or amino acid fermenters. Minimal response to all foods suggests either your dysbiosis is very mild or it’s not fermentation-driven (could be malabsorption, barrier dysfunction, or motility disorder).

Special note: People with hydrogen sulfide-dominant dysbiosis will often feel systemically worse after sulfur-containing foods (brain fog, headache, mood changes, anxiety) without necessarily dramatic bloating. This is hydrogen sulfide toxicity, not just fermentation. This pattern is a strong signal for sulfate-reducing bacteria overgrowth.

The Transit Time Marker Test

This is simple and reveals critical information.

Using the charcoal method: Take 2 to 3 activated charcoal capsules with breakfast. They’re inert, not absorbed. Note the exact time. Watch for black stool and record the time when stool turns black, which gives you approximate small intestinal transit time. Record the time when stool returns to normal color, which gives you total GI transit time.

Expected normal: First black stool 3 to 5 hours after ingestion; return to normal stool 24 hours after ingestion.

What it means if abnormal: If stool turns black in less than 2 hours, you have rapid small intestinal transit, likely due to dysbiosis, MCAS activation, or autonomic dysfunction. Your SIBO test would come back falsely negative because substrate doesn’t stay in the small intestine long enough.

If stool turns black more than 6 hours after ingestion, you have slow small intestinal transit. Your substrate might still be in your small intestine when the test ends, giving misleading results.

If stool doesn’t turn black for 8 or more hours or stool is inconsistently colored, you have severely dysregulated or patchy transit. This is a sign of serious dysbiosis or motility disorder.

This single test often explains why your breath test results don’t match your symptoms.

The Symptom-to-Stool Correlation Test

Your stool is a direct readout of your colonic microbiota. You’re going to use it as a biomarker.

Log daily for 3 weeks: stool consistency (Bristol Scale 1 to 7, with 1 being hard pellets and 7 being liquid), color (yellow, brown, tan, green, black, or gray), smell (neutral, slightly sulfurous, intensely sulfurous, fecal, sour, or unpleasant), frequency (number of stools per day), straining (yes or no, effort level), urgency (none, mild, moderate, or severe), blood or mucus (yes or no), floating or sinking (floaters suggest gas-producing dysbiosis or undigested fat), and undigested food particles (yes or no).

Correlation to dysbiosis: Loose, frequent stools (Bristol 6 to 7) with strong sulfur smell suggests hydrogen sulfide-producing bacteria, likely sulfate-reducing bacteria overgrowth. Loose stools with floating appearance suggests gas-producing bacteria plus dysbiosis-driven diarrhea. Alternating constipation and diarrhea suggests dysbiosis-driven motility dysfunction. Mucus-heavy stools suggest intestinal inflammation or dysbiosis-driven mucus hypersecretion. Stools that float initially then sink suggest dysbiosis with mixed gas production. Green or pale stools with sulfur smell suggest possible bile acid dysmetabolism plus hydrogen sulfide production.

Critical insight: If your stool pattern is abnormal, you have dysbiosis. Full stop. The breath test may or may not confirm it, but your stool is the most direct evidence of your colonic microbiota’s dysfunction.

The Symptom Provocation Plus Breath Test

This is where you actually functionally test whether you have small intestinal dysbiosis using your own physiology.

The protocol: Eat a high-FODMAP, fermentable meal based on the foods that trigger your worst symptoms from your substrate challenge tests. Track all symptoms hourly for 4 hours. Capture your breath into a bag at hours 1, 2, 3, and 4 (you can do this with a ziplock bag, closing it around your mouth). Test the breath with hydrogen sulfide strips and smell the breath.

What you’re looking for: Mouth or breath smells like rotten eggs or sulfur suggesting hydrogen sulfide is being produced and systemically absorbed (very clear sign of dysbiosis). Mouth or breath smells like overripe fruit or fermented suggesting some other volatile organic compounds from dysbiotic fermentation. Breath is neutral suggesting either you don’t have dysbiosis, or it’s not being provoked by this food, or the gas isn’t crossing your gut barrier.

Timing correlation: If symptoms appear at 30 minutes but breath smell appears at 90 minutes, your dysbiosis is producing systemic toxins that are slower to appear in breath than local GI symptoms. If breath smell appears before GI symptoms, you have very efficient gas absorption across a permeable barrier (possible barrier dysfunction).

This simple test often provides clearer evidence of dysbiosis than the breath test.

The Elimination Challenge: The Gold Standard for Dysbiosis Identification

Here’s the real test: Can you improve your symptoms by removing dysbiosis-feeding foods and adding dysbiosis-suppressing foods?

For 2 to 4 weeks, follow this protocol:

Eliminate: all high-FODMAP foods, all processed foods, all sugar and sweeteners, all vegetable oils and PUFAs (use olive oil, butter, or ghee only), and any food that provoked severe symptoms in your substrate challenges.

Add: bone broth (2 to 3 cups daily), well-cooked, safe starches (white rice, white potato), easily digestible proteins (eggs, well-cooked fish, grass-fed beef), low-FODMAP vegetables (carrot, spinach, zucchini, cucumber), fermented foods if tolerated (sauerkraut, kimchi, miso soup), and gut-supportive supplements including L-glutamine (10 grams daily), zinc carnosine (150 milligrams 2 times daily), bone broth collagen, and butyrate-producing foods (cooked then cooled white rice, if tolerated).

Track: bloating (daily 0 to 10 rating), stool consistency and frequency, symptom improvement timeline, breath odor (still testing with your nose), energy level, and mental clarity.

Interpretation: Significant improvement (more than 50 percent) within 2 to 3 weeks means your symptoms were largely dysbiosis-driven. You almost certainly have small intestinal dysbiosis, possibly with colonic involvement. Minimal improvement means either your dysbiosis is very advanced and entrenched, or your symptoms are driven by something else (barrier dysfunction, MCAS, malabsorption, motility disorder, or an organic disease). Worsening could indicate a pathogenic die-off reaction or the eliminated foods were actually supporting a beneficial microbiota and you’ve created an even worse dysbiosis (rare but possible).

This is your most important test. If you improve dramatically on this protocol, you have dysbiosis-driven symptoms. The breath test’s failure to confirm this is irrelevant. You have evidence that matters: your symptoms resolved when you changed your microbiota’s environment.

Part 3: Putting It Together

By now, you’ve gathered real data.

You likely have SIBO if you have symptoms that appeared 30 to 60 minutes after eating fermentable foods, your transit marker test showed abnormal (too fast or too slow) transit time, your substrate challenge tests provoked severe bloating, gas, or symptoms, your stool is frequently loose, floating, or foul-smelling, your breath smells sulfurous or fermented after eating, your elimination diet led to significant symptom improvement, and your symptoms resolve with gas passage or defecation. This holds even if your breath test was negative.

You might have hydrogen sulfide-predominant dysbiosis (usually missed by standard tests) if your breath test was negative or only mildly positive, you have severe neurological symptoms (brain fog, headache, anxiety), sulfur-containing foods trigger the worst symptoms, your stool smells strongly sulfurous, your breath smells sulfurous after meals, you have fatigue, joint pain, or post-exertional malaise, and you have mast cell activation symptoms that worsen with dysbiosis triggers.

You might have dysbiosis-driven barrier dysfunction if your primary symptoms are not bloating or gas but rather brain fog, headache, joint pain, or systemic inflammation, you have food sensitivities that developed recently or are worsening, your stool contains mucus regularly, you have skin reactions (rashes, flushing) after eating fermentable foods, you have symptoms of mast cell activation, and your elimination diet helps somewhat but improvement plateaus and you still feel unwell on a restricted diet.

You might not primarily have SIBO but rather malabsorption (from dysbiosis but not fermentation-driven bloating), motility disorder (dysbiosis may be secondary), or barrier dysfunction plus MCAS (dysbiosis is contributory but not primary).

What to Do Now

If you’ve confirmed dysbiosis through this self-assessment, you don’t need another breath test. You have evidence-based reason to pursue treatment targeting small intestinal dysbiosis and barrier restoration.

The treatment question is different from the diagnostic question and more nuanced than taking an antibiotic. It involves considerations such as whether you have hydrogen-producing dysbiosis versus hydrogen sulfide-producing dysbiosis (different treatment approaches), your barrier function status (damaged barrier changes the strategy), your motility status (slow transit changes the strategy), your MCAS or immune activation status (changes the strategy), and your nutritional status (informs what your system can actually use to heal).

If you’re still uncertain, work with someone who understands the mechanistic failures of breath testing and can integrate your symptom data, transit data, dietary response data, stool data, and functional history into a coherent diagnostic picture. This is exactly what functional medicine practitioners, integrative gastroenterologists, and systems-biology-trained consultants can do, something the standard SIBO breath test framework fundamentally cannot.

The Bigger Picture

The SIBO breath test became a standard because it was cheap, non-invasive, and objective. These are good things. But they created a false sense of security: the illusion that we could diagnose a complex dysbiotic state with a single three-hour measurement.

We can’t.

What you actually have is a dysbiotic ecosystem inside your small intestine with specific dominant microbial species, specific fermentation patterns, specific consequences for your barrier function and systemic health, and a specific relationship to your symptoms.

The breath test captures one narrow facet of this reality. It’s useful information if positive. But a negative result tells you almost nothing, because it was never designed to measure what you’re actually trying to find out: Is dysbiosis driving your symptoms?

You are. By tracking your own physiology, challenging your own microbiota, measuring your own transit time, and evaluating your own response to dietary intervention.

You have more data than the breath test could ever give you. And unlike the test, your data directly correlates with what actually matters: whether you improve when you change your gut’s microbial environment.

That’s not self-diagnosis. That’s functional diagnosis, the kind that actually predicts treatment response and guides real recovery.

Use it.

If you’ve tested negative on a SIBO breath test but your symptoms persist, you’re not crazy and you don’t have IBS that’s in your head. You have a dysbiotic ecosystem that the breath test wasn’t designed to detect. And now you know exactly how to detect it yourself.

That changes everything.

This article is mechanistic analysis intended to support your understanding of dysbiosis and SIBO. It is not medical diagnosis or treatment advice. Work with a qualified practitioner familiar with small intestinal dysbiosis, barrier function, and functional restoration to develop a treatment plan appropriate to your specific presentation.