For most of the last two decades, microbiome research and heavy-metal toxicology were studied as if they were unrelated fields. One asked which bacteria are present in disease. The other asked how much lead or cadmium is too much. Almost nobody asked the question that sits between them:
What happens to the microbiome when you change the metals available to it?
That question is the entire premise of microbial metallomics—the framework I've spent years developing—and it's the reason I built WikiBiome: an open encyclopedia dedicated to documenting how metals, both essential and toxic, shape the composition and behavior of human-associated microbial communities.
Metals Are Not Passive Cofactors
The standard mental model treats trace metals as nutritional footnotes—iron for hemoglobin, zinc for immune function, and a list of toxic metals to avoid. That model is wrong in a way that matters.
Metals are selection pressure. Every microbe in your gut competes for the metals it needs to run its enzymes, and many of the most dangerous pathogens depend on specific metals to power their virulence. I laid out the mechanism in detail in Microbial Metallomics: The Missing Link in Heavy Metal Contamination—nickel-dependent enzyme systems, for instance, are central to the survival of an unusually large share of the world's priority pathogens, while human cells don't require nickel at all. That asymmetry is not a coincidence. It's a target.
Change the metal environment and you change who wins. A diet, a supplement, a contaminated water supply, or a course of fertilizer-laden produce doesn't just add a toxin—it tilts an ecological playing field. This is why I argued that nickel can act as a catalytic driver of necrotizing enterocolitis in vulnerable infants: the metal activates virulence systems that would otherwise stay dormant.
Once you see the microbiome this way, you need somewhere to put the knowledge. A framework explains the principle. An encyclopedia holds the cases.
What WikiBiome Documents
WikiBiome is structured the way the problem actually decomposes—across organisms, metals, mechanisms, and diseases. It currently holds hundreds of articles spanning:
- Microorganisms — profiles of bacteria and archaea documenting their metal dependencies, acquisition strategies, and ecological roles.
- Metals — both essential metals (iron, zinc, manganese) and toxic ones (lead, cadmium, mercury, arsenic), and how each interacts with microbial physiology.
- Mechanisms — the biological processes through which metals exert their effects: detoxification systems, virulence factors, competition, and defense.
- Disease signatures — conditions mapped across multiple evidence layers, from Alzheimer's and autism spectrum disorder to cardiovascular disease, diabetes, and several cancers.
The disease-signature pages are the heart of it. Each one integrates five layers of evidence: the metallomic profile, the taxonomic changes, the host immune response, the ecological conditions, and the virulence factors at play. That structure forces the question past "these bacteria are associated with this disease" and toward "here is the metal-driven mechanism that could explain why."
Open, On Purpose
WikiBiome is a project of the Paleo Foundation, and it is deliberately open—"advancing microbiome medicine through open scientific education." That openness isn't incidental to the mission. It's the mechanism.
The fields this work draws on—metallomics, microbiology, toxicology, clinical research—don't talk to each other often enough, and when they do, the findings are locked behind paywalls and specialist vocabulary. An encyclopedia that anyone can read is how you get a toxicologist and a gastroenterologist looking at the same disease signature and recognizing the same metal. I've argued that progress here is blocked by causal reductionism—the habit of collapsing complex, multi-factor phenomena into single-cause explanations: knowledge that can't cross disciplinary lines can't be translated into care.
How It Fits the Rest of the Work
WikiBiome doesn't stand alone. It's the educational and reference layer of a connected system:
- Microbiome Medicine formalizes disease-associated microbiome patterns into clinically actionable signatures and intervention frameworks.
- The Journal of Food Metallomics advances the primary research integrating trace-metal analysis with microbiome and food-safety science.
- WikiBiome makes the synthesis of all of it openly accessible—turning primary research and clinical formalization into something a student, clinician, or curious reader can actually navigate.
Where my Heavy Metal Index traces metals from food back to the evidence, WikiBiome traces them forward—into the microbial communities they reshape and the diseases that follow. They're two halves of the same map: one external (what's in the food), one internal (what the metal does once it's inside you).
Why This Will Matter More, Not Less
Chronic disease keeps outrunning single-cause explanations. We've spent decades blaming individual nutrients, individual genes, individual pathogens—and the reductionist framing keeps failing because the body is an ecology, not a switchboard. Metals are one of the most underappreciated forces acting on that ecology, precisely because they operate at the level beneath the organisms we usually study.
WikiBiome is my bet that the next generation of microbiome medicine will be written in the language of metallomics—and that the field will move faster if the encyclopedia is open while it's being built, rather than assembled behind a wall and revealed when it's already too late to participate.
Read it, argue with it, and build on it: wikibiome.com.
WikiBiome is an open-access project of the Paleo Foundation. For the underlying framework, see Microbial Metallomics.