The brain fog investigation.
A clinical investigation guide for adults with cognitive symptoms — slow recall, word-finding, mental fatigue — and a structurally normal workup. Four pathways by which an unsuspected H. pylori infection can shift cognition without showing up on a scan.
A workup for the cognition that won't sharpen.
This guide is written for the patient whose mind feels half a step behind — whose neurology consult was clean, whose MRI was unremarkable, and whose energy keeps leaking out before the day ends. It maps four pathways by which an unsuspected H. pylori infection can shift cognition without showing up on a standard scan.
It is not a treatment protocol. It is the diagnostic conversation, written down, so the next appointment is more specific than the last.
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i.
The clinical signature of non-structural brain fogHow the symptom pattern differs from depression, ADHD, perimenopause, and post-viral cognitive presentations.
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ii.
Four pathways the cognitive workup missesB12 / methylation, non-anaemic iron, systemic inflammation, gut–brain axis — with the evidence tier for each.
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iii.
Why 'normal' B12 isn't enoughFunctional B12, methylmalonic acid, holotranscobalamin — what wide reference ranges hide.
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iv.
Labs to request beyond a basic panelMMA, homocysteine, hs-CRP, ferritin with sTfR — read together, not in isolation.
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v.
Testing options for H. pyloriStool antigen, urea breath test, biopsy — trade-offs, costs, and what each rules in or out.
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vi.
What positivity changesEradication, re-testing cognition with a structured battery, follow-up timeline.
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vii.
A conversation script for the next appointmentThree questions, phrased clinically, that route the workup toward the gastric pathway without overstating the case.
How an unsuspected infection blunts cognition.
Brain fog in the presence of H. pylori rarely runs through a single pathway. The guide treats each as testable, and grades the evidence transparently.
B12 / methylation
H. pylori-driven atrophic gastritis reduces intrinsic factor secretion. B12 deficiency presents cognitively before it presents haematologically — recall, word-finding, executive load.
Iron–brain pathway
Functional iron deficiency affects dopaminergic signalling and cerebral energy availability. Measurable cognitive decrement before haemoglobin moves.
Systemic inflammation
Sustained low-grade IL-6 / TNF-α load from gastric immune activity correlates with subjective cognitive symptoms in multiple cohorts.
Gut–brain axis
H. pylori-associated gastric dysbiosis shifts vagal signalling and downstream serotonergic precursors — a quieter pathway, under active investigation.
Sharper questions. Better appointments.
The guide doesn't replace a clinician. It gives you the language, the labs, and the literature — so the visit is a clinical conversation, not a search.
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Recognise the clinical signature of non-structural brain fog and how it differs from depression, ADHD, perimenopause, and post-viral cognitive patterns.
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Name the four pathways — B12, iron–brain, systemic inflammation, gut–brain axis — by which an unsuspected H. pylori infection can shift cognition.
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Request the right secondary labs — MMA, holotranscobalamin, hs-CRP, ferritin with sTfR — and read them in combination, not in isolation.
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Decide between testing options — stool antigen, urea breath test, biopsy — based on cost, accuracy, and your specific clinical context.
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Bring a structured conversation to your physician — three concrete questions that route the workup toward the gastric pathway without overstating the case.
Three tiers. One rubric. No exceptions.
Every claim in this guide is tagged with one of three evidence tiers. The summary below previews the four claims central to the case for investigating H. pylori in non-structural cognitive symptoms. The full reference list — eleven citations — sits at the back of the PDF.
Brain fog · evidence summary
A few honest questions.
Is this medical advice?
No. It is an investigation guide — written to inform the conversation with a clinician. Diagnosis and treatment decisions belong to your physician.
Do I need to buy the testing kit?
No. The guide is content, sold separately from any Welyon product. It covers all three standard testing options — stool antigen, urea breath test, biopsy — and tells you what each costs and how to ask for it through your existing physician or insurer.
What if my labs are 'in range'?
The guide spends a section on this exact situation — what 'in range' obscures, what to look at in combination, and the secondary markers that frequently shift the picture without changing the headline numbers.
Refund policy?
14 days, no questions. If the guide isn't useful, the Lemon Squeezy receipt has a one-click refund link. We track this to keep the guides accountable.
Who wrote it?
The investigation series is authored by Welyon's editorial team and is being reviewed by the scientific advisory board currently in formation. Reviewer names will appear in the front matter of each guide upon confirmation.
Take cognition off the 'normal' shelf. Run the investigation.
34 pages, eleven citations, four pathways, one clear path to a sharper appointment. PDF, instant download.
FDA disclaimer · Commercial interest
These statements have not been evaluated by the Food and Drug Administration. This guide is for informational purposes only and is not intended to diagnose, treat, cure, or prevent any disease. Consult your physician before acting on any information presented here.
Commercial interest disclosure. Welyon produces an at-home H. pylori testing kit and a physician-supervised Foundation Protocol referenced in this guide. The presence of these products is disclosed throughout — including on this page, the guide cover, and in the front matter of the PDF — and does not change the content of the guide. The investigation steps described would apply equally if neither product existed.
Editorial independence. Evidence grading in this guide follows the same three-tier rubric used across the H. Pylori Investigation Series, applied identically regardless of whether the resulting investigation routes a reader toward — or away from — Welyon's products.