Mar 02 2015

Blood groups, secretor status and the microbiome

Published by at 5:56 am
Under Environmental Genomics | Microbiome | Polymorphisms

It was known early in the century that ABO blood group substances occur in human tissues and secretions in two forms, water-soluble and alcohol-soluble, and that persons with these substances in saliva (secretors) have more water-soluble substances in their tissues than those lacking the substance in their saliva (non-secretors). One of the primary differences in physiology between secretors and non-secretors has to do with qualitative and quantitative differences in blood type antigen components of their saliva, mucus, and other body secretions. Two alleles, Se, and se control ABH secretion. Se is dominant and se is recessive (or amorphic). Approximately 80% of people are secretors (SeSe or Sese).


It's often not what you are eating, but what is eating you.


Secretor status and Candida albicans

ABH non-secretors are much more likely to be carriers of Candida species and to have problems with persistent Candida infections. Blood group O non-secretors are the most affected of the non-secretor blood types. One of the innate defenses against superficial infections by Candida species appears to be the ability of an individual to secrete the water-soluble form of his ABO blood group antigens into body fluids. The protective effect afforded by the secretor gene might be due to the ability of glycocompounds in the body fluids of secretors to inhibit adhesins (attachment lectins) on the surface of the yeast. In attachment studies, preincubation of certain bacterial spores with boiled secretor saliva significantly reduced their ability to bind to epithelial cells. ABH non-secretor saliva did not reduce the binding and often enhanced the numbers of attached yeasts. (2,3) In one study, among individuals with Type II diabetes, 44% of ABH non-secretors were oral carriers of this yeast. (4)

Although non-secretors make up only about 26% of the population, they are significantly over represented among individuals with either oral or vaginal Candida infections, making up almost 50% of affected individuals. (5) The inability to secrete blood group antigens in saliva also appears to be a risk factor in the development or persistence of chronic hyperplastic candidosis. In one study, the proportion of non-secretors of blood group antigens among patients with chronic hyperplastic candidosis was 68%. (6)

Women with recurrent idiopathic vulvovaginal candidosis are much more likely to be ABH non-secretors. Combining both ABH non-secretor phenotype and absence of the Lewis gene, Lewis (a- b-), the relative risk of chronic recurring vulvovaginal candidosis is between 2.41-4.39, depending on the analysis technique and control group. (7)

Oral carriage of Candida is also significantly associated with blood group O (p < 0.001) and independently, with non-secretion of blood group antigens (p < 0.001), with the trend towards carriage being greatest in group O non-secretors. (8)

Blood Groups and Microbiome

This is especially interesting in light of the fact that many of the fucosyltransferase enzymes convey blood group and/or secretor status. (9) Human feces contain enzymes produced by enteric bacteria that degrade the A, B, and H blood group antigens of gut mucin glycoproteins. The autosomal dominant ABH secretor gene together with the ABO blood group gene controls the presence and specificity of A, B, and H blood group antigens in human gut mucin glycoproteins. There is evidence that the host’s ABO blood group and secretor status affects the specificity of blood group-degrading enzymes produced by his fecal bacteria in vitro. (10) Comparatively small populations of fecal bacteria produce blood group-degrading enzymes but their presence is highly correlated with the ABO /secretor phenotype of the host: Fecal populations of B-degrading bacteria were stable over time, and their population density averaged 50,000-fold greater in blood group B secretors than in other subjects. In fact, the large populations of fecal anaerobes may be an additional source of blood group antigen substrate for blood group antigen degrading bacteria: antigens cross-reacting with blood group antigens were detected on cell walls of anaerobic bacteria from three of 10 cultures inoculated. (11)

  1. Henderson J, Seagroatt V, Goldacre M. Ovarian cancer and ABO blood groups. J Epidemiol Community Health. 1993 Aug; 47(4):287-9.
  2. Toft AD, Blackwell CC, Saadi AT, et al. Secretor status and infection in patients with Graves” disease. Autoimmunity 1990; 7(4):279-89.

8 responses so far

8 Responses to “Blood groups, secretor status and the microbiome”

  1. Randy Pifer says:

    Dr Peter D’Adamo, I read your article, but its really hard to understand for me! I’m a type O and I’m doing your type O basic pack! Could you please explain this to me, and help me to understand if its a problem for me and what I can do about it?…………….Thank You!………..,Randy Pifer

    • Lola says:

      come join us at……
      the community will help you decipher all your doubts and guide you to more written articles by Dr D.
      see you there!

  2. Jolanda Bassi says:



    How would a person test for that?

    What would be the visual clues?

    Could one make healthful changes to prevent it?

    If present orally would it be present throughout like vaginally or expressed in eczema?

    Is BTD/GENO nutrition enough to avert/prevent or is there a need for intervention?

    How soon might it return after intervention with sups (or Diflucan/Fluconazole)?

    • Andrea AWsec says:

      Hi Jolanda, first thing is to know your blood type then to do a secretor test. Knowing secretor status you can then work on a diet that is tailored to your needs. You can purchase kits for these things at this link.
      Once you have this information you can begin one of the diets. Dr. D’Adamo has written extensively on diet and health. He has a book just for diabetes which might interest you. The diets will help a great deal with candida, but the supplements will give you greater support. Taking things that are blood type specific increases your chances of success.

      Using conventional medication will treat the candida for the short term. Looking to work on the intestinal biome by increasing the good bacteria so they crowd out the bad is a much better approach. Just be aware that you may feel worse before you feel better as your body has an internal battle that it must fight. I encourage you to read all you can that Dr. D’Adamo has written his website is
      We have an active forum with loads of wonderful people.
      Andrea AWsec

  3. […] This post was mentioned on Twitter by Gisèle Frenette. Gisèle Frenette said: RT @peterdadamo: It's not just what we eat, but what is eating us: […]

  4. Linda Michaels says:

    Hi! I am a nonsecretor Blood Type 0+. Is the phenotype related to the secretor status. I understand the nonsecretor is sensitive to sugars which I am. A naturopath told me I am sensitive to sugars and carbs and he told me which foods I am sensitive to; it turns out ot be the foods the nonsecretor is most sensitive to. I notice i do the best on meats. I know meat helps the intestines produce a specific enzyme needed for the nonsecretor who is generally low in this, it is alkaline phosphatase.


  5. Marilyn Putney says:

    Nonprofessional but careful reader, I’ve referred my son and his partner to this article to inform their interest in the recently much-publicized fecal bacteriotherapy, exciting news to them. He’s O with apparent healthy digestion, she’s B with persistent systemic candidosis, neither’s secretor status is known; they’re courageous DIYers, and you know what they’re contemplating! I’ve said yikes, you’d better know what you’re doing so you don’t end up making it worse.

    Doubtless they’re not the only ones. In that light, updates and elaboration of the information in this article would be most welcome.

    Thanks, Dr. D’Adamo, for your beautiful and loving work. I’ll keep watch.