Crohn’s and Colitis, Diet and Supplements: What Was Measured, and What About Azathioprine (Imuran) and Mesalamine (Pentasa)

Inflammatory bowel disease (IBD), meaning Crohn’s disease and ulcerative colitis, is chronic immune-mediated inflammation, and “diet” and “supplements” are among the first searches after diagnosis; online, medicinal mushrooms like reishi (Ganoderma lucidum, lingzhi) and lion’s mane (Hericium erinaceus) are offered. The honest answer: none of our four mushrooms has been tested in people with Crohn’s or colitis, nor alongside azathioprine (Imuran), mesalamine (Pentasa) or a biologic. In the one trial of another mushroom’s extract, symptoms moved, calprotectin did not.

The kinds of evidence that do exist, from closest to a person to furthest away: on the disease — one registered human trial of an Agaricus extract we do not grow (two disease groups, three publications), one pilot without placebo, and dozens of studies in mice whose colitis was induced with a chemical; on the drugs — reviews of azathioprine and of mesalamine, a Cochrane review in which cordyceps was given instead of azathioprine rather than alongside it, and one study in 24 rats; on the symptom — meta-analyses of fatigue, sleep and anemia in IBD, and a reishi fatigue trial in a different population; and on what we do not sell — randomized trials of diet and of curcumin, two of them Israeli. This page is written around what you are actually asking, and says of every item what it is and what it is not. The wider picture across all autoimmune conditions is on the medicinal mushrooms and autoimmune disease page.

Is there a supplement or natural treatment for Crohn’s and colitis — and what was tested on medicinal mushrooms?

On reishi, lion’s mane, cordyceps and turkey tail — zero trials in people with Crohn’s disease or ulcerative colitis. A PubMed search for a randomized trial of any of them in these diseases returns 0. What exists is mice with chemically induced colitis, and one small trial (two disease groups, three publications) of an extract from a different mushroom — Agaricus — in which the symptoms moved and the laboratory marker of inflammation did not.

To understand what the question really is, you need to know how inflammatory bowel disease is measured. There are two kinds of measure: what the patient feels and reports — number of bowel movements, pain, blood, fatigue — and what is happening in the lining itself, measured by colonoscopy, by CRP in the blood and by fecal calprotectin, a protein released by inflammatory cells in the gut. The two do not always move together, and that is exactly where supplements fall down. A supplement that “helped Crohn’s” would have to show a change in the second kind — not only a better feeling in a short trial.

And what does the literature on our mushrooms look like? A search for “reishi and colitis” returns 27 records, “lion’s mane and colitis” — 13, “cordyceps and colitis” — 17, “turkey tail and colitis” — 10. Almost all of them are in mice and rats, and the rest in cells. Not one of them is a trial in a patient. That is why this page is not built around “which mushroom for Crohn’s”, but around what you are actually asking: what was measured in the only mushroom trial, what is permitted alongside Imuran, Pentasa or Remicade, why you are so tired, and what was tested in diet — which we do not sell.

What was measured, in which system — and what came out?

The table sorts the questions by what was measured on them and in which organism. The rows for our mushrooms are empty or in rodents. The only row with IBD patients and a mushroom extract belongs to Agaricus. The drug rows contain “not tested” or “tested as a substitute”. And the rows with randomized trials in the patients themselves belong to diet and curcumin, which we do not sell.

“A medicinal mushroom for colitis” — what was actually measured in the only mushroom trial?

One registered Norwegian trial (NCT01496053), with a colitis group and a Crohn’s group and three publications from 2016, of AndoSan, an extract based on Agaricus — a mushroom we neither grow nor sell. In colitis: the symptom score fell from 5.88 to 4.50 over 21 days, and fatigue from 16.6 to 15.1 — but fecal calprotectin and blood counts did not change at all. In Crohn’s: no significant difference from placebo. Two of the five investigators hold patents on the extract.

What the market claims. “Medicinal mushrooms calm the gut”, “Agaricus for colitis”, “proven in a clinical trial”. The trial exists — and that is exactly why it is worth reading to the end.

What exactly was measured — in colitis. 50 patients with symptomatic ulcerative colitis were randomized to the extract or to placebo, single-blind: the patients did not know what they were given. After 21 days, in the 24 patients on the extract, the symptom score fell from 5.88 to 4.71 at day 14 and to 4.50 at day 21; total fatigue fell from 16.6 to 14.1 at day 14 and came back to 15.1 at day 21. In the 26 patients on placebo — no improvement, and in the between-group comparison (mixed model) — a significant advantage for AndoSan on the self-reported scores; calprotectin — no. Four dimensions of quality of life also improved, and the patients reported no harm. But the important sentence is hidden at the end of the abstract: “there were no changes in general blood samples and fecal calprotectin”. The analysis was per-protocol — only on those who completed — and not on everyone who was randomized.

What exactly was measured — in Crohn’s. The same design, 50 patients, 25 in each group. In the extract group symptoms fell from 5.52 to 4.48 and to 4.08 compared with baseline — but the comparison that matters, against placebo, was not significant (p=0.106). Physical, mental and total fatigue improved similarly in both groups, and quality of life improved on placebo too. Calprotectin — no meaningful change. And the third publication, on blood cytokines in the patients of both groups: in Crohn’s only IL-2 fell versus placebo, in colitis only IL-5, and the authors themselves wrote that the effect was “limited” and supports an anti-inflammatory action “only marginally”.

And the other side — which has to be written. In 2011, before the randomized trials, the same group gave the extract to 11 Crohn’s patients and 10 colitis patients for 12 days, with no placebo group — and there calprotectin actually fell in the colitis patients. In other words: in a pilot without a control, the marker moved; once a placebo was added — it did not. That is a very familiar pattern in research, and it is precisely why a placebo is added.

Why it does not carry over automatically to our mushrooms. Agaricus is a different mushroom, with a different composition. But even if it had been reishi — a three-week, single-blind trial in which only self-report improved is not evidence that the inflammation in the gut went down. What can be known today: that in IBD the difference between “I feel better” and “the lining has calmed down” is real and measurable. What to ask the doctor: not “does Agaricus help” — but “when do we test calprotectin again, and what will it tell us”.

Can you take medicinal mushrooms with azathioprine (Imuran)?

Not tested. We found no study that examined a mushroom alongside azathioprine or 6-MP in IBD — a dedicated search returns 0. The studies that do exist, in kidney-transplant recipients, gave cordyceps instead of azathioprine, not alongside it. The wording we can stand behind: “not measured in humans — a question for the gastroenterologist and the pharmacist”, because azathioprine is a drug monitored with blood and liver tests.

What the market claims. Two opposite claims, both without measurement: “mushrooms strengthen the immune system and Imuran suppresses it — so they cancel each other out”, and “it’s natural, no problem”. The first assumes an interaction that was never measured; the second ignores the fact that azathioprine is a drug whose toxicity depends on its metabolism, which is why it is monitored with blood tests.

What is known about the drug. A 2021 review notes that thiopurines — azathioprine and 6-MP — have been in use for more than 50 years, and that their main safety concerns are bone-marrow suppression and life-threatening lymphoproliferative disorders. The risk of toxicity depends on genetics (the enzyme TPMT, and in Asia NUDT15) and on age, and in some patients the drug injures the liver. And what does a documented interaction look like? Allopurinol — a gout drug — changes thiopurine breakdown so much that gastroenterologists combine it deliberately, with azathioprine at a reduced dose, and use the pairing even when azathioprine has injured the liver. That is the bar: an interaction known well enough to build a protocol on.

What is known about the mushrooms. A 2015 Cochrane review gathered 5 studies in 447 kidney-transplant recipients. In 4 of them, with 265 participants, cordyceps was given as a substitute for azathioprine: anemia, white-cell counts and liver function were better, and graft survival did not differ — but Cochrane judged the risk of bias “unclear” in every study, the follow-up short (up to one year), and the results to be “interpreted with caution”; the phrase “limited low quality evidence” refers there to secondary outcomes of the fifth study, with cyclosporine. On taking cordyceps together with azathioprine — no data. And in the same field, in a trial of 202 transplant recipients on cyclosporine, those who received cordyceps in addition to their treatment were given lower doses, and their blood levels of the drug were lower. The authors wrote that cordyceps “may allow” reduced cyclosporine dosing without more rejection — the doses were set by the clinicians, and no mechanism was measured.

Why it does not carry over automatically. A kidney-transplant recipient is not a Crohn’s patient, and “instead of” is not “together with”. What can be known today: that any change in the picture — a new supplement, a new drug — is a variable in the blood tests you already have because of the Imuran. And since reishi also appears in case reports of liver injury — a 47-year-old man who took reishi powder with alcohol and recovered within two weeks — it is worth reading the medicinal mushrooms and the liver page. What to ask the doctor: “I am considering a supplement — should we bring my next blood count and liver-function test forward?”

And with mesalamine (Pentasa)?

Here too — not tested in humans. Our PubMed search found one study that puts reishi next to mesalamine: 24 rats with colitis induced by acetic acid, in four groups, and the combined group showed the lowest levels of inflammation in the tissue. That does not mean reishi “boosts” Pentasa — drug levels were not measured, and these were rats.

What is known about the drug. Mesalamine (5-ASA) is the foundation of treatment in mild-to-moderate colitis, and in Israeli Google searches it appears mostly under the name Pentasa — as tablets, suppositories and enemas. The side effect worth knowing about is renal: a 2007 systematic review found that renal toxicity from 5-ASA is “exceptional” — on average 0.26% per patient-year — with 46 patients in case reports, mostly interstitial nephritis whose signs are non-specific. It usually appears in the first year, but also after years, and it has no clear relation to dose. In other words, the pathway on which mesalamine is sensitive is the kidney — not the liver enzymes that most interaction discussions deal with.

What is known about the mushrooms. The 2022 rat study compared four groups: untreated colitis, mesalazine, reishi, and the combination. Mesalazine alone and reishi alone lowered inflammatory cytokines and CRP in the intestinal tissue, and the combination lowered them further and damaged the lining less. Acetic acid in a rat’s gut is acute chemical injury over days; ulcerative colitis in a person is a disease of years. The route and dose of reishi do not appear in the abstract. What can be known today: that there is not a single human data point — neither on the effectiveness of the combination nor on its safety. What to ask the doctor: “When did we last check creatinine?” — a question worth asking in any case, with a supplement or without one.

And with infliximab (Remicade), adalimumab (Humira) or another biologic?

Zero studies found. Not on TNF blockers — infliximab (Remicade) and adalimumab (Humira) — and not on other biologics or JAK inhibitors. Biologics are proteins that are broken down in the body differently from chemical drugs, so a liver interaction is theoretically less expected — but theory is not measurement, and “not tested” is not “safe”.

“Remicade or Humira” and “Crohn’s biologic treatment” are among the searches Google completes — people who arrive here are often on such a treatment. A search of medicinal mushrooms against infliximab, adalimumab, vedolizumab or ustekinumab returns just one record, and it is an unrelated eye report. For JAK inhibitors there is one mechanistic link: they are broken down through the enzyme CYP3A4, and reishi inhibited CYP3A in rat liver microsomes — but that was not measured in humans, so it is purely theoretical.

And the real question about biologics is not chemical but immunological: the drug is designed to quiet a specific inflammatory pathway, and a supplement that raises immune markers sits in the opposite direction on paper. Whether that changes anything in a real patient — not tested. More on that in the chapter after fatigue. What to ask the doctor: “I am on a biologic — is there a reason not to add a supplement that affects the immune system, and how would we know if something changed?”

Why are Crohn’s and colitis so exhausting — and what was measured on the fatigue?

Because fatigue is one of the most common symptoms of IBD: in a meta-analysis of 20 studies, 47% of adults with IBD reported fatigue — 72% during active disease and 47% even in remission. The common risk factors: sleep disturbance, anxiety, depression and anemia. On our mushrooms in IBD fatigue — zero studies.

What was measured on the complaint itself. The 2022 meta-analysis screened 4,524 records and included 20 good-quality studies. The pooled prevalence — 47% — varies with the definition: 28% for chronic fatigue, 48% for “high fatigue”. And what matters to you: even in remission, almost half of patients are tired. In other words, if you are tired while the disease is “quiet” — you are not imagining it, and it is not necessarily a sign of a flare.

Anemia — the cause worth ruling out first. A 2021 Cochrane review writes that iron-deficiency anemia can occur in up to 90% of IBD patients, and that it must not be assumed to be “a normal part of the disease”. It gathered 11 trials in 1,670 participants; intravenous iron produced more responders than oral iron, with fewer withdrawals because of side effects — at low certainty. This is not a matter for a supplement off the shelf; it is a matter for a blood test and a doctor.

What was measured on reishi in fatigue. The largest and cleanest trial, from 2005: 132 neurasthenia patients, reishi polysaccharide 1,800 mg three times a day, 8 weeks, double-blind. The sense of fatigue fell by 28.3% — and on placebo by 20.1%. The real difference is about eight percentage points, not 28. On clinical assessment, 51.6% in the reishi group were rated “more than minimally improved” versus 24.6% on placebo. Neurasthenia is not a bowel disease. And in the AndoSan trial in Crohn’s, fatigue improved just as much on placebo. Another trial, in 64 women with fibromyalgia, found an improvement in fitness — against carob, not against placebo; we laid it out on the fibromyalgia page.

What can be known today. A 2020 meta-analysis of 11 studies of non-drug interventions for fatigue in IBD — psychological therapies, exercise with omega-3, acupuncture, and AndoSan as well — found a small pooled effect. That is a pooling of very different things, and it cannot be attributed to the mushroom. The right order: iron, sleep, disease activity and mood — before any supplement.

What happened when reishi was tested in a population with chronic fatigue?

At the high dose, symptom severity was higher than on placebo (p=0.012); at the low dose — no change (p=0.603). That was in 2021, in a placebo-controlled, pseudo-randomized crossover trial in 29 men with Gulf War illness. That is not a bowel disease and not an “autoimmune flare” — but it is a fatigued population in which reishi was measured against placebo on symptoms.

Gulf War illness is a multi-system condition of chronic fatigue, pain and a neuro-inflammatory component, in soldiers who served in the Gulf War. It has no direct connection to Crohn’s or colitis. We bring it because it overlaps exactly with the complaint of the previous chapter — persistent fatigue against an inflammatory background — and because it is one of the few times reishi was tested in people with chronic fatigue in a controlled trial. The design: a baseline period, placebo, a low dose and a high dose. The authors’ conclusion, word for word: “reishi may exaggerate symptoms in some GWI sufferers”. And in the same breath: “the results come from a small sample and are preliminary”.

What this does and does not mean for you. It does not mean reishi worsens Crohn’s — that was not tested. It means the sentence “medicinal mushrooms can’t hurt; at worst they won’t help” does not stand up to the data: in one of the two controlled trials that measured symptoms in a fatigued population, the direction was reversed and dose-dependent. If you start a supplement — any supplement — and feel worse, that is a data point you are measuring on yourself. Stop, and tell your doctor.

Mushrooms stimulate the immune system — and you are on a drug that calms it?

That is the honest question, and the answer is “unknown”. In healthy adults, purified beta-glucan from reishi raised CD3, CD4, CD8 and NK cells against placebo over 84 days; in cancer patients, Cochrane found a 3.91% rise in CD3. That is measurable stimulation. What it does to gut inflammation in someone taking Imuran or a biologic — nobody has measured. And there is no case report of a flare after any of them either.

The question is legitimate, and it must be turned into neither an alarm nor a reassurance. On one side, in 2023 researchers gave beta-1,3;1,6-glucan from reishi to healthy adults aged 18–55 for 84 days, double-blind, and found a significant rise in CD3, CD4, CD8, the CD4/CD8 ratio and NK cells, and a significant difference in IgA whose direction the abstract does not state — with no change in kidney and liver function. A 2016 Cochrane review found, in cancer patients, a rise of 3.91% in CD3, 3.05% in CD4 and 2.02% in CD8, with study quality “insufficient”. The direction measured is up — not a two-way “balance”. We expanded on this on the reishi and the immune system page. And in the only trial of reishi (together with a herbal formula) in an autoimmune disease — 65 rheumatoid arthritis patients, 24 weeks — no change in immune cells was measured, in either direction.

On the other side, in the search we ran, not a single case report was found of an autoimmune flare after reishi, lion’s mane, cordyceps or turkey tail. The closest precedent is three patients from 2004 whose autoimmune skin disease began or flared around the time they took echinacea and spirulina — other supplements, not mushrooms. And in 2025 a scoping review from the University of Pennsylvania (with one of the authors of that 2004 report) screened 469 studies and listed reishi among 15 herbs and supplements with the strongest evidence of immune stimulation — ones that “may trigger or exacerbate autoimmune skin diseases” — on the basis of mechanism (toll-like receptor activation, NF-κB and inflammatory cytokines), not of a documented case with a mushroom. And the absence of reports is not proof of safety: adverse-event reporting for supplements is far thinner than for drugs, and a gastroenterologist whose patient flared usually will not suspect a supplement. “Not tested” is not “safe” and not “dangerous”. It is a data void, and whoever writes otherwise in either direction — is inventing.

“Reishi and lion’s mane calm gut inflammation” — what was measured in mice and in the test tube?

A lot, and none of it in humans. Ganoderic acid from reishi, polysaccharides from reishi spores and a lion’s mane polysaccharide eased colitis in mice given DSS — a chemical that induces acute damage in the gut. Another reishi molecule lowered cytokines in biopsies from children with Crohn’s — in a dish. None of them was tested in a patient, and none is a whole fruiting-body extract.

What the market claims. “Lion’s mane repairs the gut lining”, “reishi balances the microbiome”, “medicinal mushrooms for Crohn’s”. These are sentences built out of the following studies — without saying what they are.

What exactly was measured. In 2018, a polysaccharide isolated from lion’s mane was given to mice with DSS-induced colitis: clinical symptoms improved, markers of oxidative stress and inflammatory cytokines (IL-6, IL-1β, TNF-α) fell, and the composition of the gut bacteria returned to normal. In 2024, ganoderic acid A — an isolated triterpene from reishi — reduced DSS colitis in mice, preserved the mucus layer, and acted through the gut bacteria; a fecal transplant from the treated mice transferred the effect. In 2025, sporoderm-broken reishi spore polysaccharides lowered IL-17 and raised FOXP3 in the same model. In 2011, an extract of the culture medium of reishi mycelium eased TNBS-induced colitis — a Crohn’s-like model. And in 2015, another reishi triterpene, isolated as a component of a Chinese herbal formula, lowered TNF-α, IFN-γ and IL-17A in inflamed intestinal biopsies from children with Crohn’s — in a dish. The authors wrote that the finding “warrants clinical study”. No such clinical study has been published.

Why it does not carry over automatically to a person. DSS and TNBS induce acute chemical damage within days; Crohn’s and colitis are diseases of years, with their own genetics and microbiome. The molecules tested are isolated — one ganoderic acid, one polysaccharide of a defined size — not an extract; the materials came from spores and mycelium, not from the fruiting body; and a per-kilogram dose in a mouse has never been translated into a person’s cup. What can be known today: that there are interesting mechanisms that have never been tested in a single patient. What to ask the doctor: “Is there an open clinical trial I could take part in?” — that is how a mouse becomes evidence.

Reishi for sleep with Crohn’s or colitis — is there research on it?

No. There is not a single randomized trial in humans of reishi and sleep — not in IBD and not at all; a dedicated search returned one result, and it is a fitness study in fibromyalgia. And that matters precisely here: in a meta-analysis of 36 studies and 24,209 people with IBD, 56% reported poor sleep.

What the market claims. Six of Google’s fifteen completions for “reishi for…” are about sleep. What exactly was measured. In the 2005 fatigue trial, fatigue and well-being were measured — not sleep. For lion’s mane, a trial of 30 women explicitly measured a sleep-quality index, and did not report it as a significant outcome. And what was measured on your sleep. The 2022 meta-analysis found that poor sleep is more common with age and with objective disease activity — in other words, often the bad night is a sign from the gut, not a separate problem. The authors write that it is not yet known whether improving sleep improves the disease. Everything that was and was not tested on reishi and sleep is gathered on the reishi for sleep page.

What was actually measured in diet and supplements for Crohn’s and colitis — and we do not sell?

Three randomized trials worth knowing, two of them Israeli. Curcumin 3 grams a day alongside mesalamine: remission in 53.8% versus 0 on placebo, in one month. CDED nutrition with formula in children with Crohn’s: 75.6% in remission at week 12 versus 45.1%. And in adults — a restrictive diet (SCD) was not superior to a Mediterranean diet. We sell none of them.

In Hebrew, “Crohn’s diet”, “Crohn’s what not to eat” and “colitis what can I eat” are leading searches — which is why this chapter exists. Curcumin. In 2015 a team led by the gastroenterology department at Sheba, with partners in Hong Kong and Cyprus, published a double-blind trial in 50 patients with mild-to-moderate colitis who had not responded to two weeks of maximal-dose mesalamine. They received curcumin 3 grams a day (26 patients) or placebo (24), on top of the mesalamine, for one month. Clinical remission: 53.8% versus zero. Clinical response: 65.3% versus 12.5%. And the important part — endoscopic remission, meaning the lining itself: 8 of the 22 who were examined (38%) versus zero of 16. Side effects rare and similar. The caveats: one month, 50 patients, and very wide confidence intervals. And this, incidentally, is the only human trial we found in which a supplement was deliberately given alongside mesalamine and measured — something never done with a mushroom.

CDED — a trial led by Wolfson. In 2019, researchers from Wolfson and other hospitals in Israel and Canada published a randomized trial in 78 children with mild-to-moderate Crohn’s: CDED nutrition — whole food with defined restrictions, alongside formula that supplied 50% of calories and later 25% — versus formula alone (EEN) for 6 weeks followed by a free diet with 25% formula. 97.5% of the children tolerated CDED versus 73.6%. At week 6 remission did not differ significantly (75% versus 59%), and at week 12 — 75.6% versus 45.1%. And here, unlike AndoSan, remission was accompanied by a fall in CRP and calprotectin. Mediterranean diet. In 2021, in the DINE-CD trial, 194 adults with mild-to-moderate Crohn’s were assigned to a restrictive diet (SCD) or to a Mediterranean diet, with prepared meals for 6 weeks. Symptomatic remission: 46.5% versus 43.5% — no difference. Calprotectin response, among those tested: 34.8% versus 30.8% (8 of 23 and 4 of 13). CRP response was rare in both groups: 5.4% and 3.6%. The same gap between symptom and marker, this time with no supplement at all. We bring these numbers because they are what was measured — not to recommend; diet and supplements in IBD belong with a gastroenterologist and a dietitian.

Can a mushroom extract upset the gut — or confuse a stool test?

Digestive side effects have been reported, at a low rate. In the 49-week lion’s mane trial, four subjects withdrew because of abdominal discomfort, nausea and rash. With reishi, nausea and insomnia were reported. And in one case, reishi spores in the stool of a patient with chronic diarrhea were mistaken for parasite eggs — the diarrhea resolved when the supplement was stopped.

For anyone whose gut is the disease, this is a practical chapter. Lion’s mane: in a 2020 double-blind trial, with an erinacine A-enriched mycelium, four subjects dropped out because of abdominal discomfort, nausea and skin rash, and apart from them no adverse events were reported. Reishi: Cochrane 2016 lists nausea and insomnia; Cochrane 2015 found a 1.67-fold risk of any side effect — not significant and not serious. And the case worth knowing: in 2006, a 49-year-old lymphoma patient with chronic watery diarrhea was described, in whose stool test many reishi spores were found — and they were suspected of being worm eggs or a parasite. The diarrhea resolved and the spores disappeared when he stopped the supplement. If you have repeated stool tests — your doctor and the lab should know about every supplement. And if it seems to you that your gut is reacting to a supplement before you have even worked out whether it helps — the IBS and medicinal mushrooms page sets out what was measured on mushrooms and on gut symptoms without inflammation, and the side effects page gathers the rest. One last thing: a liquid extract contains alcohol — in our extracts 32% — a figure relevant to any medication list and to any sensitive gut.

What we actually measure in our bottle

After a whole page that says “not measured”, you deserve to know what was measured — and about what exactly. We grow the mushrooms ourselves, on a farm in the Galilee: fresh fruiting body, not mycelium grown on grain — like some of the materials tested in mice in the previous chapters — and not imported powder whose name on the sack cannot be verified. The mushroom goes from harvest straight to extraction, with no drying step in between; as far as we know, we are among the few in the world who work this way. The extraction is triple, and its alcohol stage runs for 7 weeks. Extraction ratios on a fresh-mushroom basis: reishi 1:3, lion’s mane 1:2 and cordyceps 1:2.5. Alcohol in the finished extract: 32% — a figure worth bringing to your doctor together with your medication list.

And the numbers are not ours to set. We sent the finished extracts for testing at TÜV Austria, and what came back is the beta-glucan percentage on a dry-matter basis — and alongside it alpha-glucan, meaning starch, which was not detected in any of them. Alpha-glucan not detected is the chemical proof that there is no grain in the bottle. To understand why that matters, it helps to know the market’s three-step ladder: mycelium grown on grain, where beta-glucan is usually below 7% and most of the weight is the grain’s starch; imported dried fruiting body, whose quality depends on who dried it and when; and fresh fruiting body from the farm, which is what we do. And on a page that talks about calprotectin, it should also be said: we have not measured what our extract does to anyone’s gut, and nobody else has either — so we will not write that it is “gentle on the gut”. Why beta-glucan and not “total polysaccharides” — we explained separately.

All our tests are public, and anyone who wants to read the report themselves will find our explanation of how to read a COA. Kosher certification — Mateh Yehuda Rabbinate, Rabbi Gad Atias. That is what we know how to measure and prove about what is in the bottle. What it will do for Crohn’s or colitis was not measured — so it is not written.

What this page does not say — and what we do not claim

We do not claim that reishi, lion’s mane, cordyceps or turkey tail calm gut inflammation, lower calprotectin, prolong remission or replace Imuran, Pentasa or a biologic — at any dose and in any form; none of them has been measured in people with Crohn’s or colitis. We do not claim that the AndoSan trial teaches anything about our mushrooms — it is a different mushroom, and the inflammation in it did not go down. We do not claim that mushrooms interfere with azathioprine or mesalamine — that was not measured; and we do not claim that they do not interfere — that was not measured either. We do not claim that they are dangerous in autoimmune disease, nor that they are safe in it. We do not claim that reishi eases fatigue or improves sleep in Crohn’s — the fatigue trial was done in a different population, and on sleep there is no trial at all. We do not claim that curcumin or a particular diet is right for you — they were tested in defined populations, for a short time, and we do not sell them. And we do not deal here with disability benefits, disability ratings, life expectancy, pregnancy or surgery — we have no expertise in those and no sources on them. What we do say: Crohn’s and colitis are diagnosed and monitored by a gastroenterologist; anyone taking Imuran, Pentasa, Remicade, Humira or steroids — talks to the doctor or pharmacist before any supplement, including ours. Under DSHEA, a dietary supplement may not claim to diagnose, treat, cure or prevent any disease. We sell mushroom extracts, and we are telling you explicitly not to buy them for your gut.

The bottom line

None of our four mushrooms has been tested in people with Crohn’s disease or ulcerative colitis; what exists on them is mice with induced colitis and isolated molecules in a dish. The only human trial of a mushroom extract we found was done on Agaricus, which we do not sell — and in it symptoms and fatigue moved in colitis, calprotectin did not, and in Crohn’s there was no difference from placebo. On combining with Imuran, Pentasa or biologics — not a single human data point; cordyceps was tested only instead of azathioprine, and reishi next to mesalamine — only in rats. The fatigue is real and measured, and before any supplement it is worth ruling out anemia, poor sleep and disease activity; and in a different fatigued population, at a high dose of reishi, symptom severity was higher than on placebo. What was tested in patients — curcumin alongside mesalamine and CDED nutrition — we do not sell. And if someone sells you a mushroom “for inflammatory bowel disease” — send them this page, and go to a gastroenterologist.

Frequently asked questions

Is there a natural treatment for Crohn’s or colitis?

No supplement has been tested as a substitute for drug treatment. What was tested in randomized trials in the patients themselves is mainly diet — CDED with formula in children with Crohn’s, and a Mediterranean diet in adults — and curcumin alongside mesalamine in colitis, for one month. None of our four mushrooms has been tested in people with inflammatory bowel disease — only in mice and in the test tube; an Agaricus extract was tested, and its calprotectin did not move.

Can I take reishi with azathioprine (Imuran)?

Not tested — we found no study that examined a mushroom alongside azathioprine. In kidney-transplant recipients, cordyceps was tested instead of azathioprine, not alongside it. Azathioprine is a drug monitored with blood counts and liver-function tests, and reishi has case reports of liver injury. It is a question for the gastroenterologist: whether to bring the tests forward if you start a new supplement.

Can I take medicinal mushrooms with mesalamine (Pentasa)?

Not tested in humans. The only study that put reishi next to mesalamine was done in 24 rats with colitis induced by acetic acid, and it did not measure drug levels. Mesalamine is sensitive mainly through the kidney — a review found exceptional renal toxicity of 0.26% per patient-year — so the question for the doctor is also when creatinine was last checked.

Does Agaricus help colitis?

In one trial of 50 patients over 21 days, the Agaricus-based extract AndoSan lowered the symptom score from 5.88 to 4.50 and improved fatigue — but fecal calprotectin did not change, the trial was single-blind, and two of the investigators hold patents. In Crohn’s there was no significant difference from placebo. Agaricus is not a mushroom we grow or sell.

Why am I tired even when the disease is in remission?

It is common and measured: in a meta-analysis of 20 studies, 47% of adults with IBD reported fatigue even in remission, and 72% during active disease. The common risk factors are sleep disturbance, anxiety, depression and anemia, and Cochrane stresses that iron-deficiency anemia is not “normal” in the disease. A blood test and a conversation with your doctor come before any supplement.

Mushrooms boost immunity — is that dangerous with a biologic?

Unknown. In healthy adults purified beta-glucan from reishi raised CD3, CD4, CD8 and NK cells — measurable stimulation. What that does to a patient on Remicade, Humira or Imuran — nobody has measured, and no case report of a flare from mushrooms was found either. “Not tested” is not “safe” and not “dangerous”; it is a question for the gastroenterologist before you start.

Does turmeric help colitis?

In a double-blind trial of 50 patients led by Sheba, curcumin 3 grams a day alongside mesalamine brought clinical remission in 53.8% versus zero on placebo, and endoscopic remission in 38% versus zero — after one month. It is a small, short trial with wide confidence intervals. We do not sell turmeric, and the decision is made with your gastroenterologist.

Is there a recommended diet for Crohn’s?

In children with mild-to-moderate Crohn’s, CDED nutrition with formula, in a trial led by Wolfson Medical Center, brought 75.6% remission at week 12 versus 45.1% in the group given formula alone for 6 weeks and then a free diet with 25% formula, with a fall in CRP and calprotectin. In adults, a Mediterranean diet and a restrictive diet produced similar symptomatic remission, 43.5% and 46.5%. The menu is built with a dietitian and a gastroenterologist.

Scientific sources (peer-reviewed)

• AndoSan (Agaricus) in ulcerative colitis — 50 patients, single-blind, 21 days: symptoms 5.88 → 4.71 → 4.50; fatigue 16.6 → 14.1 → 15.1; fecal calprotectin and blood counts — no change. Two authors hold patents — Therkelsen SP, et al. PLoS One, 2016. View on PubMed
• AndoSan in Crohn’s — 50 patients, 21 days: improvement from baseline (5.52 → 4.08), but no significant difference from placebo (p=0.106); fatigue improved similarly in both groups; calprotectin with no meaningful change — Therkelsen SP, et al. PLoS One, 2016. View on PubMed
• Cytokines in the patients of both groups: in Crohn’s only IL-2 fell versus placebo, in colitis only IL-5; the effect “limited”, anti-inflammatory “only marginally” — Therkelsen SP, et al. Scandinavian Journal of Immunology, 2016. View on PubMed
• The pilot without placebo: 11 Crohn’s and 10 colitis patients, 12 days — a fall in cytokines, and calprotectin fell in colitis — Førland DT, et al. Scandinavian Journal of Immunology, 2011. View on PubMed
• 11 studies of non-drug interventions for fatigue in IBD (psychological, exercise and omega-3, acupuncture, AndoSan) — small pooled effect, SMD 0.33 — Davis SP, et al. Complementary Therapies in Clinical Practice, 2020. View on PubMed
• Fatigue in IBD — meta-analysis of 20 studies: 47% pooled; 72% in active disease, 47% in remission; risk factors — sleep, anxiety, depression, anemia — D’Silva A, et al. Clinical Gastroenterology and Hepatology, 2022. View on PubMed
• Poor sleep in IBD — 36 studies, 24,209 people: 56%; rises with age and with objective disease activity — Barnes A, et al. Sleep Advances, 2022. View on PubMed
• Cochrane, iron-deficiency anemia in IBD: up to 90%; 11 trials, 1,670 participants; intravenous iron — more responders than oral, low certainty; “should not be assumed to be a normal finding” — Gordon M, et al. Cochrane Database of Systematic Reviews, 2021. View on PubMed
• Cochrane review of cordyceps in kidney-transplant recipients: 5 studies, 447 participants; in 4 (265 participants) cordyceps was given instead of azathioprine — not alongside it; risk of bias “unclear” in all, “interpret with caution”; “limited low quality evidence” refers to secondary outcomes of the cyclosporine study — Hong T, et al. Cochrane Database of Systematic Reviews, 2015. View on PubMed
• Low-dose azathioprine with allopurinol — “a useful duo”: a documented interaction that is used on purpose — Turbayne AK, Sparrow MP. Digestive Diseases and Sciences, 2022. View on PubMed
• Thiopurines in IBD: bone-marrow suppression and lymphoproliferative disorders; TPMT and NUDT15; allopurinol with a low dose, also in hepatotoxicity — Gargallo-Puyuelo CJ, et al. Frontiers in Medicine, 2021. View on PubMed
• 5-ASA and the kidneys — systematic review: exceptional renal toxicity, 0.26% per patient-year; 46 patients in case reports, mostly interstitial nephritis; no clear relation to dose — Gisbert JP, et al. Inflammatory Bowel Diseases, 2007. View on PubMed
• 24 rats, acetic acid colitis: mesalazine, reishi and the combination — the lowest levels with the combination. The only study of reishi next to mesalamine; not human — Özden H, et al. Annals of Surgical Treatment and Research, 2022. View on PubMed
• Reishi triterpene GAC1 on blood cells and intestinal biopsies from children with Crohn’s — in a dish: TNF-α, IFN-γ, IL-17A fell — Liu C, et al. Inflammatory Bowel Diseases, 2015. View on PubMed
• Ganoderic acid A in DSS colitis in mice: protection of the mucus layer through gut bacteria and AhR; a fecal transplant transferred the effect — Kou RW, et al. Journal of Agricultural and Food Chemistry, 2024. View on PubMed
• Lion’s mane polysaccharide in DSS colitis in C57BL/6 mice: IL-6, IL-1β, TNF-α fell; dysbiosis reversed — Ren Y, et al. The Journal of Nutritional Biochemistry, 2018. View on PubMed
• Sporoderm-broken reishi spore polysaccharides in DSS colitis in mice: IL-17 fell, FOXP3 rose — Qiao H, et al. International Journal of Biological Macromolecules, 2025. View on PubMed
• Extract of the culture medium of reishi mycelium in TNBS colitis in mice: GM-CSF rose, IFN-γ fell — Hanaoka R, et al. Scandinavian Journal of Immunology, 2011. View on PubMed
• Reishi polysaccharide inhibited CYP3A, CYP1A2 and CYP2E1 in rat liver microsomes — not in humans — Wang X, et al. Biological & Pharmaceutical Bulletin, 2007. View on PubMed
• 29 men with Gulf War illness, placebo-controlled, pseudo-randomized crossover: reishi at a low dose — no change (p=0.603); at a high dose — higher symptom severity (p=0.012); “small sample, preliminary” — Younger J, et al. International Journal of Environmental Research and Public Health, 2021. View on PubMed
• 132 neurasthenia patients, reishi polysaccharide 1,800 mg ×3 a day, 8 weeks: fatigue −28.3% versus −20.1% on placebo; “more than minimally improved” 51.6% versus 24.6%. Not IBD — Tang W, et al. Journal of Medicinal Food, 2005. View on PubMed
• Beta-glucan from reishi, healthy adults aged 18–55, 84 days, double-blind: rise in CD3, CD4, CD8, the CD4/CD8 ratio and NK cells; a significant difference in IgA, direction not stated; kidney and liver function unchanged — Chen SN, et al. Foods, 2023. View on PubMed
• Cochrane, reishi in cancer patients: CD3 +3.91%, CD4 +3.05%, CD8 +2.02%; quality “insufficient”; minor side effects — nausea and insomnia — Jin X, et al. Cochrane Database of Systematic Reviews, 2016. View on PubMed
• The only randomized trial of one of our mushrooms in an autoimmune disease: 65 rheumatoid arthritis patients, reishi + San Miao San, 24 weeks — ACR20 15% versus 9.1%, not significant; zero change in immune cells — Li EK, et al. Arthritis and Rheumatism, 2007. View on PubMed
• 202 kidney-transplant recipients: cordyceps 1.0 gram ×3 a day on top of the suppressive regimen — lower cyclosporine doses and trough blood levels in months 2–6; acute rejection 11.83% versus 15.60%, not significant; the authors: cordyceps “may allow” lower dosing — mechanism not measured — Li Y, et al. Transplantation Proceedings, 2009. View on PubMed
• 64 women with fibromyalgia, reishi 6 grams a day for 6 weeks: improvement in fitness — against carob, not against placebo — Collado Mateo D, et al. Nutrición Hospitalaria, 2015. View on PubMed
• 30 women, lion’s mane cookies for 4 weeks: sleep quality was measured and not reported as a significant outcome — Nagano M, et al. Biomedical Research (Tokyo), 2010. View on PubMed
• Three patients whose autoimmune skin disease began or flared around the time of immunostimulatory supplements — echinacea and spirulina, not mushrooms — Lee AN, Werth VP. Archives of Dermatology, 2004. View on PubMed
• Scoping review, 469 studies, 227 immunostimulatory herbal supplements: reishi among the 15 with the strongest evidence, ones that “may trigger or exacerbate autoimmune skin diseases” — on the basis of mechanism, not a case report — Weiner JD, et al. Lupus Science & Medicine, 2025. View on PubMed
• Curcumin 3 grams a day alongside mesalamine, 50 patients with mild-to-moderate colitis, one month, double-blind (Sheba, Hong Kong, Cyprus): remission 53.8% versus 0; response 65.3% versus 12.5%; endoscopic remission 38% versus 0 — Lang A, et al. Clinical Gastroenterology and Hepatology, 2015. View on PubMed
• CDED with partial formula versus formula alone for 6 weeks followed by a free diet with 25% formula, 78 children with Crohn’s: tolerance 97.5% versus 73.6%; remission at week 12 — 75.6% versus 45.1%, with a fall in CRP and calprotectin (Wolfson and partners) — Levine A, et al. Gastroenterology, 2019. View on PubMed
• DINE-CD, 194 adults with Crohn’s: SCD versus Mediterranean diet — symptomatic remission 46.5% versus 43.5%, no difference; calprotectin response 34.8% versus 30.8%; CRP response rare (5.4% and 3.6%) — Lewis JD, et al. Gastroenterology, 2021. View on PubMed
• Lion’s mane, erinacine A-enriched mycelium, 49 weeks: four subjects withdrew because of abdominal discomfort, nausea and rash — Li IC, et al. Frontiers in Aging Neuroscience, 2020. View on PubMed
• A 49-year-old patient with chronic watery diarrhea: reishi spores in the stool were suspected of being parasites; the diarrhea resolved when the supplement was stopped — Wanachiwanawin D, et al. The Southeast Asian Journal of Tropical Medicine and Public Health, 2006. View on PubMed
• Cochrane, reishi for 4 months: risk ratio 1.67 for a side effect — not significant, not serious — Klupp NL, et al. Cochrane Database of Systematic Reviews, 2015. View on PubMed
• Case report: a 47-year-old man, acute hepatitis after reishi powder with alcohol, full recovery within two weeks — Guedikian R, et al. Cureus, 2023. View on PubMed

Read next

• Medicinal mushrooms and autoimmune disease — the full picture
• IBS and medicinal mushrooms
• Medicinal mushrooms and the liver
• Fibromyalgia and supplements
• Reishi for sleep — what was measured and what was not
• Reishi and the immune system: modulation or boost?
• How mushrooms modulate the immune system
• Does reishi affect the inflammatory response?
• Drug interactions
• Do medicinal mushrooms have side effects?
• Who shouldn’t take reishi
• Medicinal mushrooms by goal — the hub
• Lab results — beta-glucan
• How to read a certificate of analysis (COA)

This page is educational and does not constitute medical advice, diagnosis or a substitute for professional care. Medicinal mushroom extracts are dietary supplements, not drugs, and are not intended to treat Crohn’s disease, ulcerative colitis or any other medical condition. Inflammatory bowel disease requires diagnosis and follow-up by a gastroenterologist, including periodic blood tests and inflammation markers; rectal bleeding, severe abdominal pain, fever or weight loss require medical attention. Do not stop, replace or change the dose of azathioprine, mesalamine, a biologic, steroids or any other medication without your physician’s guidance. It describes what published trials and case reports recorded — and what was not recorded; it is not a prediction of what any individual will experience, and it is not a recommendation to start, stop or combine any supplement with any medication — those decisions belong with your physician, especially if you take regular medication, are pregnant or breastfeeding, have surgery planned, or have liver or kidney disease. *These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.*