Among the dietary interventions discussed in hidradenitis suppurativa (HS) communities, brewer’s yeast (Saccharomyces cerevisiae) elimination has the strongest specific evidence base — modest by absolute standards, but the most consistent and mechanistically coherent of the lot. Unlike dairy elimination, where the rationale rests on indirect metabolic pathways, the brewer’s yeast hypothesis has a direct immunological framework: many HS patients have elevated antibodies against Saccharomyces cerevisiae, the same antibody pattern characteristically elevated in Crohn’s disease (which itself has a known comorbidity association with HS).
This article reviews the evidence for brewer’s yeast in HS, explains the proposed immunological mechanism, covers what “yeast-free” actually means in practice (more restrictive than it sounds), and addresses how to think about an elimination trial.
Educational content only. Dietary elimination of a major food category should be discussed with a registered dietitian or treating clinician. Patients with any history of disordered eating should not undertake elimination diets without specific clinical oversight.
Key takeaways
- The evidence for brewer’s yeast elimination in HS is the strongest of any single-food intervention, including multiple case series with reported improvement in around 70% of patients and rapid symptom recurrence on re-exposure.
- The proposed mechanism involves elevated anti-Saccharomyces cerevisiae antibodies (ASCA), which are documented in a substantial subset of HS patients and correlate with disease severity.
- “Yeast-free” goes well beyond avoiding bread — it requires eliminating beer, wine, fermented foods, many sauces, soy sauce, vinegars, malt extracts, and a wide range of processed foods.
- A reasonable trial period is 8 to 12 weeks with structured assessment, followed by deliberate reintroduction to confirm individual responsiveness.
- The intervention is unlikely to be a cure but may reduce flare frequency and severity in responsive patients, particularly those with elevated ASCA or coexisting inflammatory bowel disease.
The actual evidence
The published evidence for brewer’s yeast elimination in HS, in approximate strength:
The Cannistra series (Cannistra et al. 2013, 2016, 2020). A series of clinical observations from a single Italian centre, culminating in a 6-year follow-up published in Surgery in 2020. Of 185 HS patients evaluated, 37 followed a structured yeast-exclusion diet protocol combined with surgical treatment. 70% reported improvement in HS symptomatology, 81% of whom within 6 months. Strikingly, 87% reported immediate recurrence of skin lesions within a week of consuming a yeast-containing food — a pattern consistent with a specific food trigger rather than coincidence.
The Cannistra studies have limitations: single-centre observational design, no control group, patient-reported outcomes, possible selection bias toward motivated patients. But the consistency of the findings across multiple publications from the same team, and the specific pattern of rapid re-exposure recurrence, is more compelling than typical anecdotal evidence.
The Assan immunological study (Assan et al. 2020, Journal of Allergy and Clinical Immunology). Examined ASCA (anti-Saccharomyces cerevisiae antibodies) in HS patients versus controls. Found that both IgG and IgA ASCA were significantly elevated in HS patients compared to controls, and that elevation correlated with systemic inflammation markers and advanced disease severity. This study did not test dietary elimination as an intervention but established the immunological basis for the yeast-HS hypothesis.
Systematic reviews. The Sivanand et al. 2019 systematic review of dietary interventions in HS identified brewer’s yeast elimination as one of two specific dietary interventions (along with dairy elimination) with consistent positive case-series evidence. The 2024 Vural et al. review similarly identified brewer’s yeast elimination as warranting further investigation.
The broader context. ASCA elevation is the characteristic serological marker of Crohn’s disease. HS has a well-documented comorbidity association with inflammatory bowel disease (IBD), with elevated rates of both Crohn’s disease and ulcerative colitis in HS populations. The shared ASCA pattern across HS and Crohn’s disease provides an immunologically coherent framework: a subset of HS patients have an aberrant immune response to Saccharomyces cerevisiae or its components, which contributes to inflammatory disease in skin and (in some patients) gut.
The honest picture: stronger than for most dietary interventions in HS, but still observational and small-scale. Compelling enough that a structured trial in interested patients is reasonable, particularly those with elevated ASCA or coexisting IBD.
The mechanism: why this is biologically plausible
The immunological framework for the yeast-HS connection:
Anti-Saccharomyces cerevisiae antibodies (ASCA) are antibodies directed against mannan, a cell wall component of the yeast Saccharomyces cerevisiae. They have been recognized for decades as a serological marker associated with Crohn’s disease, where they appear in approximately 50% to 80% of patients. ASCA positivity correlates with more severe Crohn’s disease, ileal involvement, and earlier disease onset.
In HS, ASCA elevation appears at intermediate rates between healthy controls and Crohn’s disease patients. The Assan 2020 study found elevated IgG and IgA ASCA in HS, correlating with disease severity. This suggests a partial immunological overlap between HS and inflammatory bowel disease.
The implication of these antibodies in disease pathogenesis is not fully resolved. They may indicate:
- An aberrant immune response to yeast antigens, possibly cross-reactive with self-antigens (molecular mimicry)
- Increased intestinal permeability allowing inappropriate exposure of immune cells to yeast antigens that are normally tolerated
- A genetic predisposition to recognize and respond to yeast antigens as foreign
- Reflection of broader dysregulation of innate immunity against commensal organisms
Regardless of the precise mechanism, the empirical observation is that ASCA elevation tracks with chronic inflammatory disease in the gut (Crohn’s) and skin (HS), and that dietary elimination of the yeast source produces clinical benefit in a substantial proportion of patients in the available case series. The mechanistic story is more coherent than for most dietary hypotheses in dermatology.
A separate consideration: the yeast in question is specifically Saccharomyces cerevisiae, used in baking and brewing. Candida species (the yeasts implicated in mucocutaneous candidiasis) are different organisms, and elimination diets aimed at “Candida” — popular in some alternative medicine circles — are not the same intervention and do not have the same evidence base. The HS-relevant evidence is specifically about Saccharomyces, not yeast generically.
What “yeast-free” actually means
This is where the practical difficulty of the intervention becomes apparent. “Yeast-free” goes well beyond avoiding obvious yeast-leavened bread.
Direct yeast sources to eliminate:
- Yeast-leavened breads (most conventional bread, baguettes, rolls, bagels, pizza dough)
- Beer (almost all beer contains live or processed yeast)
- Wine (most wines, though distinction depends on processing)
- Champagne and sparkling wines
- Cider (alcoholic)
- Yeast extract (Marmite, Vegemite, many “savoury” flavour additives)
- Brewer’s yeast supplements
- Nutritional yeast
Foods that frequently contain yeast or yeast derivatives:
- Many sauces, marinades, and gravies (yeast extract as a savoury flavouring)
- Soy sauce and tamari (traditionally fermented; modern versions vary)
- Worcestershire sauce
- Many processed meats and stock cubes (yeast extract is a common flavour enhancer)
- Vinegars (most are fermented; distinguish from synthetic alternatives if strictness matters)
- Mature cheeses (some involve yeast in production)
- Sourdough bread (uses wild yeast and lactobacillus rather than commercial yeast, but still contains yeast)
- Soft drinks with caramel colouring (some processing involves yeast)
- Many vitamin supplements containing B vitamins derived from yeast
Foods generally acceptable on a yeast-free diet:
- Unleavened flatbreads (pita made without yeast, tortillas, chapati, matzo)
- Baking-powder-leavened products (some quick breads, biscuits, pancakes)
- Sourdough — actually contains yeast, so eliminated despite the different starter
- Spirits (distilled, so yeast is removed in the process — vodka, gin, whisky)
- Tea, coffee, water
- Fresh meat, fish, eggs (unless processed with yeast-containing additives)
- Most fresh vegetables and fruits
- Plain dairy products
The practical implication: a genuinely yeast-free diet is more restrictive than most patients initially realize. Reading ingredient labels closely is essential. Eating out becomes difficult because restaurant sauces, dressings, and prepared dishes frequently contain yeast extract. Travel becomes more complicated. Social meals require planning.
This is not as comprehensive an elimination as AIP, but it is more restrictive than dairy-free or sugar-restricted eating.
A reasonable trial elimination
If you want to test whether brewer’s yeast affects your HS, structured approach matters.
Document baseline. As with any elimination trial, the value of the test depends on knowing what you are starting from. Track flare frequency, lesion counts by location, pain levels, and photographs for at least 4 weeks before starting elimination.
Commit to thoroughness. Partial elimination of obvious yeast sources (bread, beer) without addressing yeast extract in processed foods is likely to give an unreliable answer. The Cannistra protocol involved comprehensive elimination including yeast extract in sauces and processed foods. Half-measures produce ambiguous results.
Commit to a fair trial period. 8 to 12 weeks is typical. The Cannistra data suggest that improvement, when it occurs, typically appears within 6 months in most responders, with many seeing improvement earlier.
Address nutritional gaps. Brewer’s yeast is a source of B vitamins, particularly B1, B2, B3, and B6. If you also avoid yeast-derived supplements during the trial, B vitamin intake from other sources (whole grains, leafy greens, fish, eggs, meat) needs attention. Plain dietary patterns will usually cover this, but patients with restricted other diets should pay attention.
Plan socially. Yeast elimination is harder than it sounds for restaurant meals, social gatherings, and travel. Having a plan — bringing safe foods, knowing acceptable restaurant options, scripting interactions with hosts — makes the trial sustainable.
Assess at the end of the trial period. Compare disease activity to baseline systematically. Has flare frequency decreased? Pain level? Lesion counts? The Cannistra protocol suggests that responders typically show clear improvement within the trial window. If no improvement is apparent at 12 weeks, the elimination has not produced detectable benefit for you and further restriction is not justified.
Consider deliberate reintroduction. The most striking finding in the Cannistra cohort was the 87% rate of rapid symptom return on re-exposure to yeast-containing foods. If you have experienced improvement, a deliberate reintroduction (a meal with clearly yeast-containing food, then several days of careful observation) will tell you whether the effect is genuinely yeast-specific. This is uncomfortable to consider but is the strongest individual evidence available.
If you respond and confirm, plan for long-term sustainable eating. A genuine yeast-responsive patient may benefit from long-term avoidance. The pattern should be sustainable rather than perfect — occasional unavoidable exposure followed by flares may be tolerable depending on individual severity.
What this is and isn’t
Honest framing of what brewer’s yeast elimination represents.
It is a potential adjunct intervention with intermediate evidence quality. The case series are stronger than for most dietary interventions in HS, but still observational. A trial in an interested patient is reasonable; presenting it as established treatment is not.
It is not a cure. Even in the Cannistra series, 30% of patients did not respond. Responders typically experienced improvement, not full disease resolution. Continued medical management remained appropriate.
It is not a substitute for medical management. Patients who eliminate yeast in lieu of dermatology care, biologic therapy, or other evidence-based treatment make a decision unsupported by the strength of the evidence.
It may be particularly relevant for specific subsets. Patients with elevated ASCA, patients with coexisting Crohn’s disease or other inflammatory bowel disease, and patients who report symptom patterns consistent with food triggers may be particularly likely to benefit. ASCA testing is not routine in HS care but can be requested if dietary elimination is being seriously considered.
It carries real costs. Social impact, expense (yeast-free alternatives for bread and similar staples are typically more expensive than conventional products), time investment in reading labels and meal planning, and the broader cost of restrictive eating.
FAQ
Can I just avoid beer and bread and see if that helps?
Partial elimination may be informative if symptoms improve substantially with even this limited change. But if you do not see improvement, you cannot conclude that yeast doesn’t matter for you — you may have continued consuming yeast extract in sauces, processed foods, and other less-obvious sources. A clean test requires comprehensive elimination.
Is sourdough bread acceptable on a yeast-free diet?
No. Sourdough uses a wild-yeast and lactobacillus starter rather than commercial baker’s yeast, but it still contains yeast organisms and yeast metabolic products. From the yeast-elimination perspective, sourdough is yeast-containing.
What about wine and spirits?
Wine is fermented and contains residual yeast products; most yeast-elimination protocols exclude wine. Spirits (vodka, gin, whisky) are distilled, which separates yeast from the final product; they are generally considered acceptable on yeast-free diets. Beer is strictly excluded.
Should I get tested for ASCA antibodies?
ASCA testing can be ordered through standard laboratory pathways and may be informative if you are considering structured yeast elimination. Positive ASCA does not guarantee response to elimination, and negative ASCA does not preclude it, but the test provides some biological information. Discuss with your dermatologist or gastroenterologist.
What if I have Crohn’s disease alongside HS?
The yeast-elimination case is particularly relevant for this subset, given the well-established ASCA elevation in Crohn’s disease and the shared immunological framework. Dietary management of Crohn’s disease itself often involves elimination protocols, and a yeast-free pattern may be relevant to both conditions simultaneously. Coordination between dermatology and gastroenterology care is important.
Will yeast-free eating affect my gut microbiome?
Probably. Removing fermented foods (beer, wine, vinegar, fermented vegetables, sourdough) affects exposure to certain microbial communities. Whether this is beneficial or harmful for HS specifically is unclear. Maintaining microbiome diversity through other fermented foods (yogurt if dairy is acceptable, kefir, kimchi made without yeast cultures) is reasonable where compatible.
Can I take B vitamin supplements that contain yeast-derived B vitamins?
Many B vitamin supplements are derived from Saccharomyces cerevisiae. For strict elimination, yeast-free synthetic B vitamin supplements are preferable. Check the source listed on the supplement label.
Is nutritional yeast acceptable?
No. Nutritional yeast is deactivated Saccharomyces cerevisiae, popular in vegan cooking for its umami flavour. It contains the same antigens as brewing yeast and is excluded on yeast-free diets for HS.
What about brewer’s yeast supplements (taken deliberately for B vitamins)?
These are concentrated Saccharomyces cerevisiae and would not be taken on a yeast-elimination protocol.
My HS is severe and I want to try everything. Should I do yeast elimination and AIP and dairy elimination simultaneously?
Combining multiple eliminations simultaneously produces high cumulative cost and low informational value — if you improve, you do not know which intervention was responsible. Sequential or single-intervention trials produce more useful information for less cost. If you want to try multiple dietary interventions, the order can be: easier and best-evidenced first (Mediterranean pattern, then brewer’s yeast, then dairy if needed), with broader restrictive eating only if simpler interventions are insufficient.
References
- Cannistra C et al. Treatment of hidradenitis suppurativa: Surgery and yeast (Saccharomyces cerevisiae)-exclusion diet. Results after 6 years. Surgery, 2020.
- Cannistra C, Finocchi V, Trivisonno A, Tambasco D. New perspectives in the treatment of hidradenitis suppurativa: Surgery and brewer’s yeast-exclusion diet. Surgery, 2013.
- Assan F et al. Anti-Saccharomyces cerevisiae IgG and IgA antibodies are associated with systemic inflammation and advanced disease in hidradenitis suppurativa. Journal of Allergy and Clinical Immunology, 2020.
- Sivanand A et al. Weight Loss and Dietary Interventions for Hidradenitis Suppurativa: A Systematic Review. Journal of Cutaneous Medicine and Surgery, 2019.
- Vural S et al. Evaluating dietary considerations in hidradenitis suppurativa: a critical examination of existing knowledge. International Journal of Dermatology, 2024.
