Provisional scaffold. This page was created automatically on 2026-06-02 so that an ingested source could route to it. Aliases, category, and the contamination profile have not yet been populated. Content below is minimal until a synthesis pass consolidates the literature for this ingredient.
Reason: ingest of bezrodnykh2023-crayfish-chitosan-residual-metals declared chitosan which did not exist
Triggering source: A Walkway from Crayfish to Oligochitosan
Literature scope
Reported measurements from source notes are below. No typical or upper-tail value is calculated here, and no certification limit is stated. The contamination profile in the page frontmatter is unchanged.
Reported measurements
The 2023 note reports residual metals in laboratory chitosan made from crayfish shell. Chitosan iron was 3.7 ppm. Oligochitosan hydrochloride iron was 2.8 ppm. Chromium and nickel are not measured as a chitosan concentration (the table prints them as not found, and the note prints no numeric detection limit for those cells). Cadmium, lead, mercury, and arsenic are not measured as a chitosan concentration (the note says preliminary ICP-MS did not find them in crude waste, and it prints no number). Crude shell waste iron 23.0 ppm is the starting waste, not chitosan, and is not repeated here as a chitosan result. Chromium at 0.4 ppm and nickel at 0.3 ppm in that waste are not measured as a chitosan concentration. Chitin rows are not chitosan and are not repeated here. The authors’ comparators are USP 34-NF29 acceptance limits, and chromium, nickel, lead, cadmium, mercury, and arsenic in those limits are not measured as a chitosan concentration: iron at or below 10 ppm, chromium at or below 1 ppm, nickel at or below 1 ppm, lead at or below 0.5 ppm, cadmium at or below 0.2 ppm, mercury at or below 0.2 ppm, and arsenic at or below 0.5 ppm. A Walkway from Crayfish to Oligochitosan
Chitosan iron and the iron-microbiota review
The measurement behind this section is residual iron in laboratory chitosan from crayfish shell, not a gut endpoint. The iron and gut microbiota review cited below reports other human studies and does not add a food concentration. A chitosan manufacturer can cite it for the direction of iron status in other human studies. It does not characterize chitosan, shell waste, or oligochitosan.
Bao et al. 2024, per WikiBiome source summary, DOI 10.3390/ijms25020727, is a review of iron homeostasis and gut microbiota. The note states that iron deficiency anemia was associated with lower Bacillota and higher Bacteroidota, Pseudomonadota, and Patescibacteria, and that iron-deficient women had lower fecal Lactobacillus. It also states that iron supplementation increased Enterobacteriaceae and decreased Lactobacillus in infants, and that iron fortification increased Bacteroidetes in African children. Sample sizes are not in the note. The direction summarized is iron status toward gut microbiota. The review does not test this ingredient.
Study table
| Study | Model | Metal and dose | Main finding | Limitation |
|---|---|---|---|---|
| Bao et al. 2024 | Review of human studies | Iron deficiency and supplementation; doses not in the note | Deficiency and supplementation shifted fecal taxa, including Lactobacillus | Per WikiBiome source summary; not this ingredient |
What remains uncertain
The review note does not print sample sizes or doses. It does not mention chitosan, chitin, or shellfish processing. Chromium and nickel that appear as comparator limits on the chitosan page were not measured as chitosan concentrations in the source note, and they are not given gut findings here.
References
Works cited in this page’s text, in first-appearance order. See Sources for this page’s source inventory. Each title links to a source record with bibliographic details, reported findings, and document provenance.
- A Walkway from Crayfish to OligochitosanPeer-reviewed
- Mechanism of Iron Ion Homeostasis in Intestinal Immunity and Gut Microbiota RemodelingPeer-reviewed
Sources
Source records associated with this topic. Inclusion does not establish that every finding applies to this product or ingredient. References above identify works cited in the text.
| # | Citation | Year | Type | Used on this page for |
|---|---|---|---|---|
| 1 | Bezrodnykh et al. 2023. A Walkway from Crayfish to Oligochitosan, Applied Sciences | 2023 | Peer-reviewed | RU Fe, Cr, Ni, Pb, Cd, tHg, tAs, Al occurrence in One laboratory processing batch from 4 kg fresh-frozen narrow-toed crayfish (Actacus leptodactylus) bought on a local market and… (n=1) |
Update history
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