What is secretor status?
Secretor status says whether your body puts ABO blood-group sugars, rich in fucose, into your saliva, mucus and gut lining. It depends on one gene, FUT2. With at least one working copy you are a secretor; with two non-working copies you are a non-secretor. In people of European ancestry this is almost always the W143X variant (rs601338). It is a different gene from your blood group: an O secretor and an A non-secretor are both possible.
| Secretor | Non-secretor | |
|---|---|---|
| How common (European ancestry) | about 80% | about 20% |
| Fucose sugars on the gut lining | Present | Absent |
| Gut bacteria | More bifidobacteria on average in several studies | A different mix, often fewer bifidobacteria |
| Blood vitamin B12 | Slightly lower on average | Slightly higher on average |
| Most common norovirus strains | Susceptible | Much less susceptible |
How we read it from your DNA file
23andMe and AncestryDNA files contain the main FUT2 variant, rs601338. MyHeritage files lack it, so we read rs492602, which is inherited with it: on the real files we checked, the two gave the same answer every time (49 of 49). The check runs entirely in your browser; your file is not sent anywhere.
Secretor status and the blood type diet
Secretor status is popular among followers of the blood type diet, and some companies sell secretor tests for 150 to 175 US dollars as part of such programs. A Canadian study of 1,455 people found that the benefits of blood type diets had nothing to do with the person's blood group. Secretor status does matter for the gut: in a German study of 8,956 people, blood group and secretor status together were linked with some gut bacteria. That is a reason to understand it, not a diet rule.
Limits
- This check is built for people of European ancestry. In East Asian populations, secretor status often depends on other FUT2 variants (such as rs1047781) that it does not read.
- It is educational information, not a medical test, and it does not tell you which bacteria live in your gut. What DNA can and cannot say about your microbiome
Read more: Non-secretor: what it means for your gut bacteria, vitamin B12 and norovirus · How to choose a gut microbiome test
Frequently asked questions
What is a non-secretor?
Someone with two non-working copies of the FUT2 gene. Their saliva, mucus and gut lining lack the fucose-rich sugars of the ABO blood-group system. It is not a disease.
How common is being a non-secretor?
About 1 in 5 people of European ancestry. Frequencies differ in other populations.
Can I find my secretor status with 23andMe or AncestryDNA?
Yes. Both read rs601338, the main FUT2 variant. Download your raw data file and drop it in this free tool. MyHeritage files lack that marker, so we read a linked one, rs492602.
Is secretor status the same as blood type?
No. Blood type comes from the ABO gene, secretor status from FUT2. You can have any blood type and be either a secretor or a non-secretor.
Should non-secretors follow a special diet?
No specific diet has been proven. A varied, fiber-rich diet that feeds bifidobacteria is a sensible choice, and vitamin B12 needs depend on diet, age and medicines, not on FUT2.
Is my DNA file uploaded?
No. The file is read in your browser and nothing is sent to our server. Only the answers to the optional survey are.