Put simply, FUT2 makes a natural prebiotic in secretions: gut, saliva, vagina, urinary tract. Without it, your microbiome will always be prone to problems, because your body simply can’t sustain – on its own – a healthy microbiome.
These microbiome disruptions are likely to occur primarily in the gut but also anywhere that has these secretions – vagina, urinary tract, mouth, and respiratory tract – leading to infections that may never seem to resolve fully.
The results may include gut problems such as irritable bowel syndrome (IBS), inflammatory bowel disease, urinary tract infections (UTIs), bacterial vaginosis (BV), B12 deficiency, autoimmune disease, allergies, and mouth infections.
The FUT2 gene plays a crucial role in the interplay between genetics, immunity, and the microbiome. Mutations leading to non-secretor status can influence susceptibility to infections, chronic diseases, and poor microbiome health.
FUT2 function
The FUT2 gene encodes an enzyme called α(1,2)-fucosyltransferase. This enzyme adds fucose, a prebiotic sugar, to precursor molecules, creating H antigen on epithelial cell surfaces and in secretions.
FUT2 activity determines whether an individual is a secretor or non-secretor.
Secretors vs non-secretors
A FUT2 secretor has functional FUT2; H antigen is present in secretions (e.g., saliva, mucus), acting as a natural prebiotic.
Non-secretors have inactive or less functional FUT2 (due to genetic mutations), and H antigen is absent in secretions.
FUT2 genetic mutations
The most common mutation associated with non-secretor status is G428A (rs601338), leading to a premature stop codon and loss of enzyme activity. Around 20-25% of people of European descent are non-secretors, but the frequency varies by population.
Health implications of FUT2 genetic mutations and non-secretors
The FUT2 gene plays a pivotal role in shaping the human microbiome, influencing health in profound ways.
FUT2 and the gut microbiome
Secretor status, determined by FUT2 functionality, directly impacts the composition of the gut microbiome. Secretors, with their functional FUT2 gene, typically harbour higher levels of beneficial bacteria such as Bifidobacteria.
In contrast, non-secretors often exhibit altered microbial communities, potentially affecting immunity and digestion.
FUT2 and infection susceptiblity
This genetic variation also modulates susceptibility to infections. Non-secretors are notably less vulnerable to certain strains of norovirus, as the virus relies on H antigen for attachment—a molecule absent in non-secretors.
However, this same genetic trait may heighten susceptibility to Helicobacter pylori, linking FUT2 mutations to an increased likelihood of these infections.
FUT2 and autoimmune and inflammatory disease
Beyond infections, FUT2 mutations are associated with autoimmune and inflammatory diseases. Non-secretor status has been linked to a higher risk of Crohn’s disease, particularly in the ileum, as well as celiac disease and type 1 diabetes.
These conditions may, in part, arise from the altered microbiome composition characteristic of non-secretors.
How FUT2 impacts vitamin B12 absorption
The gene also influences vitamin B12 absorption, as FUT2 plays a role in regulating intrinsic factor, a critical component of B12 uptake. Non-secretors, therefore, are more prone to low serum B12 levels, which can have cascading effects on overall health.
FUT2 and UTIs and BV
Non-secretors may have increased susceptibility to urinary tract infections (UTIs) and vaginal infections like bacterial vaginosis due to changes in epithelial cell surface markers.
FUT2 and allergies, eczema, periodontal disease
Allergic conditions such as asthma and eczema also appear more prevalent among non-secretors, suggesting an intricate interplay between genetics and immune function. Non-secretors also have a heightened risk of periodontal disease.
FUT2 and fertility
Finally, FUT2 expression in vaginal and uterine epithelia underscores its significance in fertility and reproductive health. Alterations in this pathway may affect susceptibility to infections and influence reproductive outcomes, making FUT2 a critical factor in the broader context of human health.
Testing for FUT2 Mutations
- Specific genetic testing (e.g., SNP testing) can identify FUT2 mutations
- Common genealogy genetic testing tests for several FUT2 SNPs (Ancestry, 23andme, MyHeritage, etc.) (your My Vagina practitioner can easily use the raw data to find these, and many other, mutations)
- Commonly tested SNPs include rs601338 (G428A) and rs602662
Practical solutions for non-secretors
For individuals with FUT2 non-secretor status, practical strategies can help mitigate the associated health challenges and optimize well-being. These approaches focus on supporting the microbiome, enhancing nutrient absorption, and reducing susceptibility to infections.
Probiotics and probiotic foods
One of the most effective interventions for non-secretors is the targeted use of probiotics, particularly strains of Bifidobacteria.
Since non-secretors often have reduced levels of these beneficial microbes due to the lack of fucose in their secretions, supplementing with specific probiotic strains can help restore balance.
Probiotic supplementation supports digestion, strengthens the immune system, and fosters resilience against pathogenic bacteria. Selecting high-quality probiotics tailored to individual needs can significantly enhance gut health and overall microbiome diversity.
Vitamin B12 supplementation
Maintaining adequate vitamin B12 levels is another critical consideration. The reduced availability of intrinsic factor in non-secretors can impair B12 absorption, increasing the risk of deficiencies that affect energy, cognitive function, and overall health.
Regular monitoring of serum B12 levels, combined with supplementation if necessary, ensures that this vital nutrient is consistently available to the body. Injections of methyl or hydroxy B12 may be more useful than oral supplements, since this bypasses the gut completely.
Preventing infections
Given their heightened susceptibility to certain infections, non-secretors should adopt proactive measures for infection prevention.
Vigilance is particularly important for gut and urinary tract infections, as altered epithelial surface markers and microbiome imbalances may create opportunities for pathogens to thrive.
Practices such as maintaining hydration, ensuring proper hygiene, and incorporating antimicrobial dietary elements like cranberry and garlic can reduce infection risks.
Eating the right prebiotic foods
Dietary choices play a foundational role in supporting a healthy microbiome for non-secretors. Prebiotic fibres, such as inulin and resistant starches, are particularly beneficial.
These fibres nourish beneficial bacteria like Bifidobacteria and Akkermansia muciniphila, promoting their growth even without fucose.
Diets rich in vegetables, whole grains, and fermented foods not only enhance microbial diversity but also contribute to overall digestive and immune health.
Non-secretors may also consider functional foods and supplements specifically designed to boost mucosal health and support a balanced microbiome.
Can’t we just take FUT2 or fucose as a supplement?
Yes, but you’ll usually need a practitioner to prescribe these. Book here.
Rebuilding the microbiome and keeping it healthy
Using these strategies, FUT2 non-secretors can use diet, supplementation, and proactive health practices to achieve a resilient and thriving microbiome, improved immunity, and overall better health.
Getting support for FUT2 mutations
My Vagina naturopaths can help you navigate the issues with a FUT2 genetic mutation that is causing you microbiome issues, providing targeted treatments and advice.
References1–4
- 1.Ferrer-Admetlla A, Sikora M, Laayouni H, et al. A Natural History of FUT2 Polymorphism in Humans. Molecular Biology and Evolution. Published online June 1, 2009:1993-2003. doi:10.1093/molbev/msp108
- 2.Kaur P, Gupta M, Sagar V. FUT2 gene as a genetic susceptible marker of infectious diseases: A Review. Int J Mol Epidemiol Genet. 2022;13(1):1-14. https://www.ncbi.nlm.nih.gov/pubmed/35892094
- 3.McGovern DPB, Jones MR, Taylor KD, et al. Fucosyltransferase 2 (FUT2) non-secretor status is associated with Crohn’s disease. Human Molecular Genetics. Published online June 22, 2010:3468-3476. doi:10.1093/hmg/ddq248
- 4.Galeev A, Suwandi A, Cepic A, Basu M, Baines JF, Grassl GA. The role of the blood group-related glycosyltransferases FUT2 and B4GALNT2 in susceptibility to infectious disease. International Journal of Medical Microbiology. Published online April 2021:151487. doi:10.1016/j.ijmm.2021.151487
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