H. pylori: A Functional Nutritionist's Guide to Symptoms, Testing and Gut Recovery
Written by Rita Soares, Nutricionista, Ordem dos Nutricionistas 2604N, Institute for Functional Medicine (IFM) member
Helicobacter pylori is a spiral-shaped bacterium that colonises the lining of the stomach, where it survives the acid that kills almost everything else. It is the most common chronic bacterial infection in humans. Most people who carry it never develop an ulcer. A significant minority develop chronic gastritis, nutrient deficiencies, and, over decades, a measurably higher risk of gastric cancer.
This guide covers what the infection does, how it is correctly tested for, why two people with the same positive result can have completely different clinical pictures, and where nutrition genuinely changes the outcome. It is written for people who have just tested positive, who have been treated and still feel unwell, or who suspect H. pylori is behind symptoms that have been dismissed as "just stress".
In this article: what H. pylori is and how it survives · symptoms · why the same infection affects people so differently · iron, B12 and long-term risk · testing and the errors that cause false negatives · why treatment is often not the end of the story · where nutrition makes a difference · what not to do · when to seek medical investigation · how I work with H. pylori ·
FAQ · references
What H. pylori is and how it survives
H. pylori is a gram-negative, spiral bacterium adapted to one of the most hostile environments in the body. It burrows through the gastric mucus layer to sit against the epithelium, where the pH is closer to neutral, and it produces urease, an enzyme that splits urea into ammonia and carbon dioxide, neutralising acid in its immediate surroundings. That urease is also what makes the breath test possible.
It is remarkably common. In the most recent global systematic review, more than half the world's population was infected as of 2015, with wide variation between regions (Hooi et al., 2017, Gastroenterology). Colonisation is usually acquired in childhood, typically within households, and without treatment it persists for life.
The Maastricht VI/Florence consensus, the reference guideline for European practice, now formally classifies H. pylori infection as an infectious disease, whether or not the person has symptoms (Malfertheiner et al., 2022, Gut).
That reclassification matters. It moved the question from "is this causing your symptoms?" to "why is it still there, and what has it already done?"
Symptoms: what H. pylori feels like
Most carriers are asymptomatic. When symptoms do appear, they are usually upper-digestive rather than lower-digestive:
Burning or gnawing pain in the upper abdomen, often worse on an empty stomach
Early satiety, feeling full after a few mouthfuls
Persistent nausea, particularly in the morning
Belching, upper bloating and a sense of food "sitting" in the stomach
Reflux-type symptoms that respond poorly, or only partially, to acid suppression
Bad breath that dental hygiene does not resolve
Unexplained fatigue, which is frequently the iron story rather than the stomach story
The pattern that should raise suspicion is upper-abdominal symptoms combined with an iron deficiency nobody can explain, particularly when a course of iron supplementation has not held.
Note what is not on that list: lower bloating that builds through the day, urgency, alternating stool form. Those point toward the small and large intestine, the territory of SIBO and IBS, and they can coexist with H. pylori without being caused by it. Separating upper from lower symptoms carefully, before deciding what to treat, is one of the most useful things that happens in a first consultation.
Why the same infection affects people so differently
If most carriers never develop disease, the interesting clinical question is not "do you have it" but "why is it causing damage in you".
Several factors determine that:
Strain virulence. CagA-positive and VacA s1/m1 strains provoke substantially more epithelial inflammation than less virulent genotypes.
Mucosal defence. The gastric mucus layer, mucosal blood flow and prostaglandin signalling all determine how much damage a given bacterial load causes. NSAIDs undercut all three, which is why regular NSAID use alongside H. pylori is considerably worse than either alone.
Where it colonises. Antrum versus corpus changes whether the result tends toward high-acid duodenal ulceration or low-acid atrophy: two very different long-term trajectories.
The host inflammatory response. Much of the tissue damage in H. pylori gastritis is driven by the immune response to the organism, not by the organism directly.
Nutritional status. High salt intake, low intake of antioxidant-rich vegetables and poor vitamin C status are all associated with worse gastric mucosal outcomes in infected populations.
Chronic stress and sleep debt. Both alter gastric secretion, mucosal perfusion and immune regulation. This is the part patients recognise immediately and the part conventional care rarely addresses.
None of this is a reason to leave an infection untreated. It is the reason that clearing the organism does not automatically restore the terrain it was living in, and the reason two people need quite different support afterwards.
Beyond the stomach: iron, B12 and long-term risk
This is where H. pylori stops being a stomach problem and becomes a systems problem.
Iron. Chronic H. pylori gastritis is associated with iron deficiency anaemia, with a pooled odds ratio of 1.72 across observational studies. More usefully: randomised trials show that treating the infection alongside iron supplementation raises ferritin more than iron supplementation alone (Hudak et al., 2017, Helicobacter). If your ferritin will not climb despite supplementing, an untreated stomach infection is one of the explanations worth excluding.
Stomach acid and B12. The infection alters acid secretion, and long-standing infection can progress to atrophic gastritis, in which acid-producing parietal cells are lost. Adequate stomach acid is required to liberate B12 from food protein and to reduce dietary iron into its absorbable form. This is the mechanism that connects a stomach infection to fatigue, stubbornly low ferritin and, over longer periods, B12 depletion, and it is also why low stomach acid appears on the root-cause list for small intestinal bacterial overgrowth.
Long-term risk. H. pylori is the most important modifiable risk factor for gastric cancer, and gastric cancer prevention is one of the central reasons the Maastricht VI consensus recommends treating the infection wherever it is found (Malfertheiner et al., 2022, Gut). The clearest evidence comes from a randomised trial in first-degree relatives of gastric cancer patients: among those in whom the infection was successfully cleared, gastric cancer incidence was 0.27 times that of those with persistent infection (95% CI, 0.10-0.70) (Choi et al., 2020, New England Journal of Medicine).
That trial is the reason I do not treat H. pylori as optional, and the reason this article does not offer a herbal protocol as an alternative to proper medical treatment.
Testing: which test, when, and the errors that cause false negatives
There are four ways to test, and they are not interchangeable.
Test | What it detects | Best used for | Main limitation |
Urea breath test | Active infection (urease activity) | First-line diagnosis and confirming clearance | Invalidated by recent PPIs or antibiotics |
Stool antigen test | Active infection (bacterial antigen) | First-line diagnosis and confirmation | Same medication interference |
Endoscopy with biopsy | Active infection, tissue damage, antibiotic susceptibility | Alarm symptoms, previous treatment failure, staging atrophy | Invasive, requires referral |
Serology (blood antibodies) | Past or present exposure | Epidemiology, rarely clinical | Cannot distinguish current from cleared infection |
Serology is the test most often misused. A positive antibody result tells you that you have encountered H. pylori at some point. It cannot tell you whether you are infected today, and antibodies can remain positive long after an infection has cleared. If a blood test is all you have had, you have not yet been properly assessed.
The preparation errors that produce false negatives are entirely avoidable and extremely common:
Proton pump inhibitors must be stopped for at least two weeks before a breath or stool test. PPIs suppress urease activity and bacterial load, and testing while taking them is the single most frequent cause of a falsely reassuring result.
Antibiotics and bismuth must be stopped for at least four weeks before testing.
Confirmation of clearance must be done at least four weeks after finishing treatment, using a breath or stool test, never serology.
That last point deserves emphasis, because it is where most people are let down. Clearance is not confirmed by symptoms improving. It is confirmed by a negative breath or stool test, taken at the right interval. If nobody retested you, you do not actually know whether your treatment worked.
Why treatment is often not the end of the story
Medical treatment for H. pylori is prescribed and supervised by a doctor, and when it works, it works definitively. It should be the backbone of care. But patients arrive in my clinic regularly having been treated and still feeling unwell, and there are four usual reasons.
The infection was never confirmed cleared. Confirmation testing is skipped so often that a meaningful number of people believe they have cleared an infection they still have.
The nutrient debt was never repaid. Years of gastritis and altered acid production deplete iron and B12 quietly. Clearing the organism stops the depletion; it does not reverse it. Nobody feels well at a ferritin of 12 µg/L simply because their breath test came back negative.
The gut took collateral damage. Combination antibiotic regimens do not act only on the stomach. Reduced bacterial diversity, loose stools, new bloating and new food reactivity are common in the weeks afterwards, and are the reason some people feel worse after successful treatment than before it.
Something else was there all along. In a condition this common, attributing every symptom to H. pylori is how a second diagnosis gets missed for years. Persistent lower-digestive symptoms after confirmed clearance usually point somewhere else entirely.
Where nutrition actually makes a difference
Search for "H. pylori diet" and you will find long lists of foods that supposedly "fight" or "eliminate" the bacterium. Almost none of that content distinguishes between a compound that inhibits H. pylori in a petri dish and one that changes an outcome in a person. That distinction is the whole point, and it is worth being honest about where the evidence actually sits.
During treatment, nutritional support measurably improves outcomes. A meta-analysis of randomised trials found that adding appropriate probiotic support to eradication therapy improved treatment success and roughly halved the rate of diarrhoea, with total adverse effects falling substantially (Tong et al., 2007, Alimentary Pharmacology & Therapeutics). That matters for a practical reason as much as a biological one: people who tolerate a course finish it, and abandoned courses are how resistance develops. Which strains, at what dose, and how they are timed around the medication is where the clinical detail lives, and it is not one-size-fits-all.
Some foods genuinely reduce bacterial load, and are still not a cure. In a randomised trial, adults eating sulforaphane-rich broccoli sprouts daily for eight weeks showed falls in urea breath test values, stool antigen levels and markers of gastric inflammation. The effects reversed two months after the sprouts stopped (Yanaka et al., 2009, Cancer Prevention Research). That study is the best evidence in this category and it makes the point precisely: the infection was suppressed and the gastritis calmed, but the organism was not eradicated and the benefit disappeared when the intervention stopped. That is what a genuine adjunct looks like: useful, and not a substitute.
Some things clearly make it worse. High salt intake, heavy alcohol, smoking and routine NSAID use all worsen gastric mucosal outcomes in infected people. Reducing these is not a soft suggestion.
And the repair work is where most of the remaining symptoms live. Once the organism is confirmed gone, the questions worth asking are whether digestive capacity has recovered, whether microbial diversity is being rebuilt at a pace the gut can tolerate, whether iron and B12 are actually being absorbed again, and whether the mucosa is being given what it needs to heal. Each of those is assessable, and each needs a different answer depending on how long the infection was present, what the treatment was, and what the person's baseline looked like. That sequencing is the work: doing it in the wrong order is why well-intentioned protocols so often stall.
For most people the underlying eating pattern is not exotic: vegetables, olive oil, oily fish and legumes, salt kept genuinely low, cruciferous vegetables several times a week. A Mediterranean pattern has the best supporting evidence for gastric mucosal health. What it does not do is replace an individualised plan when there is real damage to repair.
What not to do
Do not use a natural protocol as a substitute for medical treatment. This is the most consequential error in the wellness content on this topic. Given what is known about persistent infection and gastric cancer risk, delaying treatment in favour of herbs is a trade that does not make sense, and I will not design one.
Do not stay on a PPI indefinitely without a plan. Acid suppression manages symptoms while leaving both the infection and the underlying acid dynamics unaddressed, and it will invalidate your test results.
Do not skip the confirmation test because you feel better.
Do not self-prescribe from the internet. The supplements most often recommended for H. pylori are the ones most likely to interfere with testing, mask symptoms, or be taken at the wrong point in the sequence.
When to seek medical investigation
See a doctor without delay if any of the following are present. These require endoscopy, not nutrition:
Difficulty swallowing, or food sticking
Unintentional weight loss
Vomiting blood, or black, tarry stools
Persistent vomiting
A palpable abdominal mass or unexplained anaemia
New-onset upper-digestive symptoms after age 50
A first-degree relative with gastric cancer
How I work with H. pylori in practice
Full history and timeline. When symptoms began, what was tried, which tests were run, on what medication, and what the results actually showed rather than what was reported.
Close the testing gaps. Establishing whether the infection is present now, whether clearance was ever confirmed, and whether nutrient status has ever been properly measured.
Coordinate rather than compete. Eradication is prescribed and supervised medically. I work alongside it: on tolerance, on nutrient repletion, and on protecting the rest of the gut.
Rebuild in the right order. Digestive capacity, mucosal repair, microbial diversity and nutrient status, sequenced rather than attempted all at once.
Reassess at three months. If symptoms persist despite confirmed clearance, we investigate what else is there instead of repeating something that already worked.
This is the structure of my Gut Health Reset Program, and mapping it out for your particular history is what a consultation is for.
Working through a positive H. pylori result, or still unwell after treatment? I see patients in person in Lisbon and online, in English and Portuguese. Book a consultation
Key takeaways
H. pylori is carried by more than half the world's population, and most carriers have no symptoms, a positive result does not by itself explain everything you are feeling.
It is now formally classified as an infectious disease, symptomatic or not.
Serology cannot tell you whether you are currently infected. Breath or stool testing can, and only if PPIs and antibiotics have been stopped for long enough beforehand.
Confirmation testing four weeks after treatment is the step most often skipped and the one that matters most.
Symptoms that persist after confirmed clearance usually come from the nutrient debt, the disrupted microbiome, or a second condition, not from residual infection.
Nutrition does not eradicate H. pylori. It improves tolerance of treatment, and it is what repairs the damage the infection left behind.
Frequently asked questions
Can H. pylori be cured naturally without antibiotics? There is no human evidence that any dietary or herbal protocol reliably eradicates H. pylori. Some compounds reduce bacterial load or gastric inflammation, which is useful support, but given the established link between persistent infection and gastric cancer, using them in place of medical treatment is not a reasonable trade.
How do I know if my H. pylori treatment actually worked? Only a urea breath test or stool antigen test, performed at least four weeks after the last antibiotic dose and off PPIs for two weeks, can confirm clearance. Symptom improvement is not confirmation, and a blood antibody test cannot tell you: antibodies persist long after an infection has cleared.
Why do I still have symptoms after H. pylori was treated? Usually one of four things: the infection was never confirmed cleared, iron or B12 were never repleted, the antibiotics disrupted the wider gut microbiome, or a second condition such as small intestinal bacterial overgrowth was unmasked. Each is investigated differently, which is why the order matters.
Can H. pylori cause fatigue? Indirectly, yes. Chronic gastritis is associated with iron deficiency anaemia, and impaired acid production reduces both iron and B12 absorption. Fatigue with an iron deficiency that will not correct on supplementation is a recognised presentation and is worth investigating.
Is H. pylori linked to bloating? It more typically causes upper-abdominal fullness, early satiety and belching than the lower bloating associated with SIBO or IBS. The two can coexist, which is why upper and lower symptoms should be separated carefully before deciding what to treat.
Should my family be tested if I am positive? Transmission is largely within households, so testing close family members is often reasonable, and it becomes considerably more important where there is a family history of gastric cancer, since that is the group in which clearing the infection has shown the clearest preventive benefit.
Does H. pylori come back after treatment? True reinfection is relatively uncommon in adults in high-income settings, though it does happen. More often, an apparent recurrence is a treatment failure that was never detected, because confirmation testing was skipped.
Scientific references
Hooi JKY, Lai WY, Ng WK, et al. Global Prevalence of Helicobacter pylori Infection: Systematic Review and Meta-Analysis. Gastroenterology. 2017;153(2):420-429. https://doi.org/10.1053/j.gastro.2017.04.022
Malfertheiner P, Megraud F, Rokkas T, et al. Management of Helicobacter pylori infection: the Maastricht VI/Florence consensus report. Gut. 2022;71(9):1724-1762. https://doi.org/10.1136/gutjnl-2022-327745
Hudak L, Jaraisy A, Haj S, Muhsen K. An updated systematic review and meta-analysis on the association between Helicobacter pylori infection and iron deficiency anemia. Helicobacter. 2017;22(1):e12330. https://doi.org/10.1111/hel.12330
Choi IJ, Kim CG, Lee JY, et al. Family History of Gastric Cancer and Helicobacter pylori Treatment. New England Journal of Medicine. 2020;382(5):427-436. https://doi.org/10.1056/NEJMoa1909666
Tong JL, Ran ZH, Shen J, Zhang CX, Xiao SD. Meta-analysis: the effect of supplementation with probiotics on eradication rates and adverse events during Helicobacter pylori eradication therapy. Alimentary Pharmacology & Therapeutics. 2007;25(2):155-168. https://doi.org/10.1111/j.1365-2036.2006.03179.x
Yanaka A, Fahey JW, Fukumoto A, et al. Dietary Sulforaphane-Rich Broccoli Sprouts Reduce Colonization and Attenuate Gastritis in Helicobacter pylori-Infected Mice and Humans. Cancer Prevention Research. 2009;2(4):353-360. https://doi.org/10.1158/1940-6207.CAPR-08-0192
About the author
Rita Soares is a functional medicine nutritionist based in Lisbon, registered with the Ordem dos Nutricionistas (2604N) and a member of the Institute for Functional Medicine (IFM), with over 11 years of clinical experience. She works in English and Portuguese, seeing patients in person in Lisbon and online. Her clinical focus is gut health: SIBO, IBS, H. pylori, gastritis and the microbiome, using a root-cause, systems-biology approach.
Related reading
Disclaimer
This article is for educational purposes and does not constitute medical advice, diagnosis or treatment. H. pylori eradication is a medical treatment that must be prescribed and supervised by a physician. Always consult a qualified healthcare professional before changing your diet, supplements or medication.
Comments