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Primary topic: FUT2 gene gut microbiome

FUT2 Gene and Metabolism: What It Means for Your Body

FUT2 shapes how certain glycans are expressed in the gut environment, which can influence microbiome behavior and downstream nutrient handling.

What is the FUT2 gene?

FUT2 affects secretor status, which changes the sugars presented on mucosal surfaces. Those sugars influence which microbes colonize more easily and how the gut environment supports microbial balance.

How FUT2 affects metabolism

When FUT2-related signals reduce secretor activity, microbiome composition can shift. That may indirectly affect nutrient extraction, gut resilience, immune signaling, and tolerance to certain foods or supplements.

What happens when FUT2 is altered

Altered FUT2 activity does not automatically mean gut problems, but it can explain why microbiome support, digestive resilience, or nutrient tolerance behaves differently from generic expectations.

Curated SNP evidence for FUT2

These SNPs come from the approved study-level evidence model. Each claim is scored from curated study rows, then gated before it can influence pathway scoring.

B12 transport Histamine

Evidence-backed report connection

FUT2 currently has 3 curated SNPs, 7 claim-level scores, and 1 claims eligible for pathway scoring.

Open the sample report
rs492602FUT2 204G>A B12 locus1 claims · 3 study rows

biomarker tendency · A

plasma vitamin B12 tendency

Moderate

rs492602 A at FUT2 is associated with lower circulating vitamin B12 biomarker tendency.

FUT2 rs492602 A is staged as a lower total plasma vitamin B12 tendency allele with supporting holo-haptocorrin/secretor biology.

Likely effectLower biomarker tendency
Signal sizeSmall signal
Evidence supportStrong support
Report useIncluded in pathway scoring
Show study evidence
PMID 18776911gwas · directThe checked GWAS record supports rs492602 at FUT2 as a genome-wide plasma vitamin B12 locus, with the A allele reported in follow-up summaries as the lower-B12 allele.PMCID PMC3243448biomarker association · directThe checked plasma B12 study reports FUT2 204G>A / rs492602 among B12-related SNPs strongly associated with lower plasma B12 concentrations and includes holo-haptocorrin measurements.PMCID PMC5886113biomarker association · close proxyThe checked FUT2 secretor-variant source supports a mechanism in which FUT2 genotype influences haptocorrin-bound B12 and haptocorrin glycosylation, providing close transport/status support for the rs492602 plasma B12 signal.
rs601338Secretor-status signal3 claims · 6 study rows

enzyme activity · AA

FUT2 enzyme activity

Not used for pathway scoring

rs601338 AA is associated with reduced FUT2 enzyme activity.

This SNP is scored as a strong lower FUT2 activity tendency for AA, consistent with the common non-secretor genotype; AG and GG are scored as secretor-range for this SNP.

Likely effectLower enzyme activity signal
Signal sizeSmall signal
Evidence supportModerate support
Report useEvidence only, not scored
Show study evidence
Evidence 1identity only · unknownNCBI dbSNP lists rs601338 in FUT2 as NM_000511.6:c.461G>A, producing p.Trp154Ter, a stop-gained change in galactoside alpha-(1,2)-fucosyltransferase 2.PMC6171556other · loose proxyThe ALSPAC FUT2 secretor-status study defines rs601338 G as the wild-type secretor allele and A as the nonsense non-secretor allele. It treats the A allele as recessive, grouping GA and GG as secretors and comparing them with AA non-secretors.

enzyme activity · AG

FUT2 enzyme activity

Not used for pathway scoring

rs601338 AG has no scored directional claim for FUT2 enzyme activity.

This SNP is scored as a strong lower FUT2 activity tendency for AA, consistent with the common non-secretor genotype; AG and GG are scored as secretor-range for this SNP.

Likely effectNo clear enzyme signal
Signal sizeMinimal signal
Evidence supportVery limited support
Report useEvidence only, not scored
Show study evidence
Evidence 1identity only · unknownNCBI dbSNP lists rs601338 in FUT2 as NM_000511.6:c.461G>A, producing p.Trp154Ter, a stop-gained change in galactoside alpha-(1,2)-fucosyltransferase 2.PMC6171556other · loose proxyThe ALSPAC FUT2 secretor-status study defines rs601338 G as the wild-type secretor allele and A as the nonsense non-secretor allele. It treats the A allele as recessive, grouping GA and GG as secretors and comparing them with AA non-secretors.

enzyme activity · GG

FUT2 enzyme activity

Not used for pathway scoring

rs601338 GG has no scored directional claim for FUT2 enzyme activity.

This SNP is scored as a strong lower FUT2 activity tendency for AA, consistent with the common non-secretor genotype; AG and GG are scored as secretor-range for this SNP.

Likely effectNo clear enzyme signal
Signal sizeMinimal signal
Evidence supportVery limited support
Report useEvidence only, not scored
Show study evidence
Evidence 1identity only · unknownNCBI dbSNP lists rs601338 in FUT2 as NM_000511.6:c.461G>A, producing p.Trp154Ter, a stop-gained change in galactoside alpha-(1,2)-fucosyltransferase 2.PMC6171556other · loose proxyThe ALSPAC FUT2 secretor-status study defines rs601338 G as the wild-type secretor allele and A as the nonsense non-secretor allele. It treats the A allele as recessive, grouping GA and GG as secretors and comparing them with AA non-secretors.
rs602662FUT2 supporting signal3 claims · 9 study rows

biomarker tendency · AA

FUT2 biomarker tendency

Not used for pathway scoring

rs602662 AA is associated with increased FUT2 biomarker tendency.

This SNP is scored as a modest tendency toward higher serum vitamin B12 for A-containing genotypes, based on association evidence.

Likely effectHigher biomarker tendency
Signal sizeSmall signal
Evidence supportLimited support
Report useEvidence only, not scored
Show study evidence
Evidence 1identity only · unknownNCBI dbSNP lists rs602662 in FUT2 as NM_000511.6:c.772G>A, producing p.Gly258Ser in galactoside alpha-(1,2)-fucosyltransferase 2.PMC2667971gwas · close proxyA genome-wide association study of circulating B-vitamin concentrations identified rs602662 in FUT2 as associated with vitamin B12 serum levels and reported that the A allele was associated with higher vitamin B12 concentrations.PMC6171556biomarker association · close proxyThe ALSPAC FUT2 study reported high correlation between rs602662 and rs601338 and little change in secretor-status classification when rs602662 was added. It is retained as proxy context, not independent directional vitamin B12 evidence.

biomarker tendency · AG

FUT2 biomarker tendency

Not used for pathway scoring

rs602662 AG is associated with increased FUT2 biomarker tendency.

This SNP is scored as a modest tendency toward higher serum vitamin B12 for A-containing genotypes, based on association evidence.

Likely effectHigher biomarker tendency
Signal sizeMinimal signal
Evidence supportLimited support
Report useEvidence only, not scored
Show study evidence
Evidence 1identity only · unknownNCBI dbSNP lists rs602662 in FUT2 as NM_000511.6:c.772G>A, producing p.Gly258Ser in galactoside alpha-(1,2)-fucosyltransferase 2.PMC2667971gwas · close proxyA genome-wide association study of circulating B-vitamin concentrations identified rs602662 in FUT2 as associated with vitamin B12 serum levels and reported that the A allele was associated with higher vitamin B12 concentrations.PMC6171556biomarker association · close proxyThe ALSPAC FUT2 study reported high correlation between rs602662 and rs601338 and little change in secretor-status classification when rs602662 was added. It is retained as proxy context, not independent directional vitamin B12 evidence.

biomarker tendency · GG

FUT2 biomarker tendency

Not used for pathway scoring

rs602662 GG has no scored directional claim for FUT2 biomarker tendency.

This SNP is scored as a modest tendency toward higher serum vitamin B12 for A-containing genotypes, based on association evidence.

Likely effectNo clear biomarker tendency
Signal sizeMinimal signal
Evidence supportVery limited support
Report useEvidence only, not scored
Show study evidence
Evidence 1identity only · unknownNCBI dbSNP lists rs602662 in FUT2 as NM_000511.6:c.772G>A, producing p.Gly258Ser in galactoside alpha-(1,2)-fucosyltransferase 2.PMC2667971gwas · close proxyA genome-wide association study of circulating B-vitamin concentrations identified rs602662 in FUT2 as associated with vitamin B12 serum levels and reported that the A allele was associated with higher vitamin B12 concentrations.PMC6171556biomarker association · close proxyThe ALSPAC FUT2 study reported high correlation between rs602662 and rs601338 and little change in secretor-status classification when rs602662 was added. It is retained as proxy context, not independent directional vitamin B12 evidence.

Common symptoms people report

  • digestive variability without a clear pattern
  • bloating or poor tolerance to some foods
  • gut issues that seem linked to immunity or inflammation
  • uncertain response to probiotic or fiber interventions

Biomarkers to validate

Stool microbiome profile

Can add directional context for microbial balance when symptoms justify testing.

Vitamin B12

Useful where gut status and nutrient handling overlap.

Inflammatory markers such as hs-CRP

Helpful if gut disruption and systemic load appear linked.

Where DNA analysis helps

DNA can flag gut-environment pathways that might deserve more structured follow-up when symptoms are messy. It helps narrow hypotheses before broad supplement experimentation.

Example Insight

Your gut-environment pathway may create more variability in microbiome-related responses than expected.

Suggested validation: stool profile plus hs-CRP if symptoms justify it.

What to do next

  • Use symptoms and biomarkers together instead of over-reading one gene.
  • Compare FUT2 with DAO and histamine-related patterns if food tolerance is inconsistent.
  • Treat microbiome interventions as testable follow-up, not automatic fixes.

Upload your DNA file and receive a structured metabolic pathway analysis with prioritized insights and suggested validation markers.

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Related pages

DAO

DAO gene histamine metabolism

HNMT

HNMT gene histamine metabolism

DAO activity

DAO activity and histamine clearance

Ferritin and inflammatory context

Ferritin and inflammatory context DNA follow-up

Inflammation and immune signaling pathway

inflammation immune signaling pathway

B12 transport and recycling pathway

B12 transport and recycling pathway

Can DNA predict metabolism?

can DNA predict metabolism

DNA nutrition analysis report

DNA nutrition analysis report

Related symptom angle

Histamine intolerance genetics

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