Yeasts are different from other fungi in that they are unicellular fungi. Baking yeast is in the Saccharomycetaceae
family of microorganisms. They are used to make baked goods, wine and beer. This page does not cover non-food yeasts which cause human infections.
Nutritional yeast is the same species, Saccharomyces cerevisiae
, but it has been cultured, heated and dried, so is essentially deactivated.
The main allergen in this specific yeast is an enolase protein
An allergy to yeast has been linked to anaphylaxis after a Hepatitis B vaccination (shot) as it contains trace amounts of yeast. This is an incredibly rare event, but something to mention to your health provider if you are allergic to yeast and need this specific vaccination.
Yeast is a low FODMAP food. FODMAP
stands for F
olyols. Foods high in FODMAPs can cause symptoms of food intolerance, affecting the gastro intestinal system and this can be mistaken for a true IgE food allergy.
You can read more about Food Intolerances
on the dedicated Food Intolerance Page.
Baking yeast is an inhalant allergen as well as a food allergen and is associated with Bakers Asthma, which is an occupational allergic syndrome.
Yeast can also be linked to rhinitis and atopic dermatitis.
Diets high in yeast are linked to irritable bowel disease, ulcerative colitis and Chron's Disease. Reducing the amount eaten can be beneficial to those suffering from these conditions.
Enolase proteins are also found in various species of fish including carp, cod and salmon and in poultry meat like chicken or turkey.
Note that this food list is not exhaustive, you can find the most up to date information on the Cross Reactivity Tool.
Allergen Encyclopdeia - Yeast
Science Direct - Saccharomyces cerivisiae
Articles and Journals
Allergic Reactions to Vaccines in Children: From Constituents to Specific Vaccines, 2023
Sensitisation to molecular components of fungi in atopic dermatitis patients, the relation to the occurrence of food hypersensitivity reactions, 2022
Anaphylaxis to a particular brew of beer due to specific strains of Saccharomyces cerevisiae, 2022
Anaphylaxis to additives in vaccines, 2022
Consumption of Yeast-Fermented Wheat and Rye Breads Increases Colitis and Mortality in a Mouse Model of Colitis, 2022
Atopic Dermatitis and Sensitisation to Molecular Components of Alternaria, Cladosporium, Penicillium, Aspergillus, and Malassezia—Results of Allergy Explorer ALEX 2, 2021
Occupational rhinitis and asthma in bakers: a cross-sectional study in the former Katanga province of DR Congo, 2021
Beer, Cider, and Wine Allergy, 2017
Clustered sensitivity to fungi: anaphylactic reactions caused by ingestive allergy to yeasts, 2006
Looking for immunotolerance: a case of allergy to baker's yeast (Saccharomyces cerevisiae), 2005
Yeast metabolic products, yeast antigens and yeasts as possible triggers for irritable bowel syndrome, 2005
Skin prick test response to enzyme enolase of the baker's yeast (Saccharomyces cerevisiae) in diagnosis of respiratory allergy, 2001
Skin prick test reactions to brewer's yeast (Saccharomyces cerevisiae) in adult atopic dermatitis patients, 1993
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