Proposed perspective: 5fC, deuterium and a dysregulated methylome
This abstract presents a perspective, not tested human results: it argues that 5-formylcytosine (5fC) may be enriched in deuterium and act as a marker of deuterium overload in one-carbon units, with proposed links to aging and disease. [1]
Automatic summary · not editorially reviewed
The key findings
The authors argue that 5fC, an intermediary in TET enzyme modifications, is highly enriched in deuterium due to the high deuterium kinetic isotope effect of TET enzymes. [1]
The authors suggest that, similar to TMAO, 5fC serves as a marker for deuterium overload in one-carbon units. [1]
The authors propose that increased 5fC bases lead to an accelerated rate of aging, associated with increased disease risk. [1]
The source at a glance
- Study type / format
- Perspective (abstract)
- Population / context
- Not specified; the abstract discusses proposed molecular mechanisms rather than a study population.
- Summary based on
- Study abstract
- Publication status
- Preprint · peer-review status not confirmed
- Original publication
- October 8, 2026
Proposed role of 5fC in DNA and nucleosomes
The authors describe the methylation pathway as a major part of epigenetics, controlling which genes are expressed through hypo- and hypermethylation of cytosine bases in DNA. They report that 5-formylcytosine (5fC), a rare and poorly understood modified base, can influence DNA mutations and repair, alter nucleosome structure and introduce DNA-protein cross-links. They argue that 5fC, an intermediary in modifications by ten-eleven translocation (TET) enzymes, is highly enriched in deuterium because of the high deuterium kinetic isotope effect of TET enzymes. A deuteron is said to impede the step converting 5fC to 5-carboxylcytosine (5caC). These are the authors' proposals in an abstract, not established findings.
Supporting source [1]
Proposed deuterium marker and microbiome link
The authors suggest that, similar to trimethylamine oxide (TMAO), 5fC serves as a marker for deuterium overload in the one-carbon units carried by methionine in the methylation pathway and through methyl tetrahydrofolate (CH3-THF) and its derivatives. They state that the gut microbiome strips deuterium out of carriers of one-carbon units via hydrogen gas recycling. Nutrients such as choline, L-carnitine and betaine are said to supply one-carbon units bound to nitrogen atoms that feed into the one-carbon pool via microbial enzymes. Anaerobic archaea are described as essential; when under-represented, deuterium is said to become enriched in one-carbon units. These proposed mechanisms are not tested outcomes in this abstract.
Supporting source [1]
Proposed aging and disease consequences
The authors propose that this ultimately increases the number of 5fC bases in DNA, leading to an accelerated rate of aging, which they associate with increased risk of infection, autoimmune disease, cardiovascular disease and cancer. They further propose that oxidative stress due to deuterium overload in ATPase nanomotors suppresses TET enzyme activity, inducing hypermethylation of promoters of tumor suppressive enzymes and facilitating cancer progression. The abstract presents this as a perspective for a new pathogenesis avenue due to a dysregulated methylome. No study design, sample, follow-up or measured outcome is reported, so these links remain proposals rather than demonstrated causes.
Supporting source [1]
How to interpret this
Abstract only; the full text was not reviewed. This is a perspective with proposed mechanisms; no study design, sample, follow-up or measured outcomes are reported, so the aging and disease links are not demonstrated.
Based on the study abstract; the full paper, tables and supplementary data were not reviewed.
Source & supporting passages
Seneff S, Kyriakopoulos AM. · europepmc.org · October 8, 2026