Thorne Sacro-B Review
Thorne's Sacro-B provides substantial support to the health of the gastrointestinal tract. Each capsule provides a minimum of 5 billion CFUs of Saccharomyces boulardii, a clinically studied species of yeast that has demonstrated its ability to increase the production of secretory IgA, the first-line defense immunoglobin in the GI tract. The page lists its benefits as supporting healthy immune function in the gut, supporting the growth of beneficial intestinal flora, helping to mitigate occasional bouts of diarrhea, and providing probiotic support during travel. Its listed features are 5 billion CFUs per capsule up until time of expiration, an easy to take one capsule serving size, and shelf stability with no refrigeration required. The page describes who may benefit as individuals who need to rebuild healthy gut flora, such as after a course of meds, people who will be traveling, particularly to foreign places, people who are currently taking a med, because as a yeast it is not destroyed by a med, and people who experience occasional diarrhea. The product is listed as third party tested and certified to verify that what is in the package matches the label and to confirm it contains no unsafe levels of contaminants such as heavy metals, pesticides, and microorganisms. The Warnings section states that the product is contraindicated in an individual with a history of hypersensitivity to any of its ingredients, that it contains a product derived from yeast, and that anyone who is pregnant should consult a health-care practitioner before using it. The page reports no known adverse interactions or contraindications at publication date. It also advises that the Sacro-B powder should not be removed from the capsule, because the capsule is inherent to the product's intended delivery mechanism. The product is sold at $43 for 60 capsules, or $38.70 with a subscription that gives 10% off, with subscription frequencies ranging from every 2 weeks to every 4 months and free shipping on subscriptions. The page also notes that the product is HSA and FSA eligible.
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Study, Trial or Testing Result Summary
Members Only31 human studies · 25 improved
This product gives 750 mg a day of the probiotic yeast Saccharomyces boulardii, above the 500 mg a day that worked in studies. Most of the strong evidence comes from people taking meds for a stomach infection. Across 19 studies of 5,036 such people, adding this yeast cut the risk of bloating by about half and constipation by about 60%, and also reduced diarrhea and nausea, though not abdominal pain [1]. In 15 trials of 2,156 children on the same treatment, side effects fell from 29.2% to 9.2%, with less constipation, abdominal pain and swelling [2], and another review of 29 trials in children ranked this yeast best for reducing bloating [3]. In 160 adults, 500 mg a day for 2 weeks alongside meds led to less bloating and abdominal discomfort [4]. In irritable bowel syndrome, a review of 42 trials with 3,856 people found better relief of abdominal pain, with no more side effects than controls [5]. Not every result is positive: in 15 trials of 1,087 children with long-term constipation, probiotics did not improve weekly bowel movements, and this yeast did worse than mixed probiotics or a laxative for stool consistency [6]. Animal and cell studies are never counted.
See all 31 studies →Hide the studies
- Across 19 studies of 5,036 people treated for Helicobacter pylori, adding Saccharomyces boulardii to standard therapy cut the risk of bloating by about half and constipation by about 60%, and also reduced diarrhea and nausea, though not abdominal pain.Efficacy and safety of Saccharomyces boulardii as an adjuvant therapy for the eradication of Helicobacter pylori: a meta…
- In 23 trials of 3,938 children taking meds, probiotics cut a med-associated diarrhea from 19% to 8%, and Saccharomyces boulardii was among the strains judged appropriate; gas and bloating appeared only as rare side effects.Read the study on PubMed (26695080) →
- In 42 trials of 3,856 people with irritable bowel syndrome, Saccharomyces boulardii CNCM I-745 improved abdominal pain relief compared with controls (risk ratio 1.5), with no more side effects than controls.Strain-specific and outcome-specific efficacy of probiotics for the treatment of irritable bowel syndrome: A systematic …
- In 29 trials of 3,122 children treated for Helicobacter pylori, probiotics added to standard therapy reduced side effects, and Saccharomyces boulardii ranked best for reducing bloating.Efficacy and safety of probiotic-supplemented triple therapy for eradication of Helicobacter pylori in children: a syste…
- In 15 trials of 2,156 children treated for Helicobacter pylori, adding Saccharomyces boulardii lowered total side effects (9.2% vs 29.2%) and diarrhea, and also reduced constipation, abdominal pain and abdominal distention.The effect of Saccharomyces boulardii supplementation on Helicobacter pylori eradication in children: a systematic revie…
- In 15 trials of 1,087 children with functional constipation, no significant difference in weekly bowel movements was found between probiotics and placebo, and Saccharomyces boulardii was less effective than mixed probiotics or lactulose for stool consistency (very low to low certainty).Efficacy and Safety of Probiotics, Prebiotics and Synbiotics for the Treatment of Functional Constipation in Children: S…
- Latin American experts reviewing the literature recommended Saccharomyces boulardii for treating acute diarrhea and preventing a med-associated and traveler's diarrhea in children, but not for irritable bowel symptoms.The use of probiotics in pediatric gastroenterology: a review of the literature and recommendations by Latin-American ex…
- A review of 249 trials found strong evidence that Saccharomyces boulardii I-745 helps prevent a med-associated diarrhea, with two probiotic types showing strong efficacy for irritable bowel disease.Choosing an appropriate probiotic product for your patient: An evidence-based practical guide.
- In 240 children treated with meds for a stomach infection, adding 500 mg a day of this probiotic yeast for 2 weeks significantly lowered mouth sores, constipation and diarrhea compared with meds alone, with no significant change in nausea, vomiting or abdominal pain or in infection clearance.[Clinical effect of triple therapy combined with Saccharomyces boulardii in the treatment of Helicobacter pylori infecti…
- In 160 adults treated for a stomach infection, taking 500 mg a day of this probiotic yeast for 2 weeks alongside meds led to less nausea, diarrhea, abdominal discomfort and bloating in the first two weeks than meds alone, though infection clearance did not differ significantly.The efficacy and safety of adding the probiotic Saccharomyces boulardiito standard triple therapy for eradication of H.p…
- In 156 patients treated for a stomach infection, adding this probiotic yeast for 2 weeks to meds made nausea, diarrhea, headache, abdominal pain and anxiety significantly less likely than with placebo, with no significant difference in infection clearance.Investigating the effect of quadruple therapy with Saccharomyces boulardii or Lactobacillus reuteri strain (DSMZ 17648) …
- In 150 adults taking vonoprazan and amoxicillin for Helicobacter pylori, adding Saccharomyces boulardii 250 mg twice daily for 10 days did not improve eradication but lowered the rate of side effects, especially abdominal pain.Effects of supplementing with Saccharomyces boulardii on vonoprazan-amoxicillin dual therapy for naive Helicobacter pylo…
- In 124 patients taking meds for a stomach infection for 2 weeks, this probiotic yeast cut diarrhea (14.5% vs 30.6%) and upper stomach discomfort (14.5% vs 43.5%) versus placebo and improved dyspepsia scores, while abdominal gas was similar in both groups.Efficacy and safety of Saccharomyces boulardii in the 14-day triple anti-Helicobacter pylori therapy: a prospective rand…
- In 85 children with amebic diarrhea, adding S. boulardii to metronidazole did not shorten diarrhea compared with metronidazole alone.Efficacy and safety of Saccharomyces boulardii in amebiasis-associated diarrhea in children.
- In 72 people with diarrhea-predominant irritable bowel syndrome, 750 mg per day of S. boulardii for 6 weeks lowered inflammatory signals and improved quality of life more than placebo.Cytokine and clinical response to Saccharomyces boulardii therapy in diarrhea-dominant irritable bowel syndrome: a rando…
- In 70 people with diarrhea-predominant irritable bowel syndrome, 250 mg of S. boulardii twice daily for one month produced no difference from placebo.Role of Saccharomyces boulardii in diarrhea predominant irritable bowel syndrome.
- In 67 adults with diarrhea-predominant or mixed irritable bowel syndrome, 4 weeks of Saccharomyces boulardii improved quality of life more than placebo, but it did not beat placebo for individual symptoms.A randomized, double-blind, placebo-controlled multicenter trial of saccharomyces boulardii in irritable bowel syndrome:…
- In 60 children with diarrhea-predominant irritable bowel syndrome, 14 days of Saccharomyces boulardii lowered symptom severity scores and normalized stool form.Saccharomyces boulardii's impact on pediatric diarrhea-predominant irritable bowel syndrome: animal model findings.
- In 54 adults with acute amebiasis, adding 250 mg of S. boulardii three times daily to meds shortened diarrhea from about 48 to 12 hours and cleared cysts more often by week 4.Read the study on PubMed (12918131) →
- In 48 symptomatic children with Blastocystis hominis, 250 mg of S. boulardii twice daily for 10 days led to clinical cure in 78% by day 15, versus 40% with no treatment.Clinical efficacy of Saccharomyces boulardii or metronidazole in symptomatic children with Blastocystis hominis infectio…
- In 48 adults with irritable bowel syndrome with diarrhea and bacterial overgrowth, taking S. boulardii with diet advice for 15 days reduced gas-breath test readings and diarrhea more than diet advice alone.Impact of Saccharomyces boulardii CNCM I-745 on Bacterial Overgrowth and Composition of Intestinal Microbiota in Diarrhe…
- In 47 adults with irritable bowel syndrome, a two-month blend of probiotics including Saccharomyces boulardii with fiber and fruit extracts improved quality of life more than placebo, though the Saccharomyces boulardii dose was not stated.Effects of a polyphenol-rich extract blend, probiotics, and hydrolyzed fiber on quality of life and gut health markers i…
- In 42 healthy adults taking miglustat, adding Saccharomyces boulardii 500 mg twice daily did not significantly reduce diarrhea days overall, though a post hoc analysis suggested fewer gut side effects.A double-blind, randomized, placebo-controlled trial studying the effects of Saccharomyces boulardii on the gastrointest…
- In 60 adults with type 2 diabetes and H. pylori-linked gastritis, adding S. boulardii yeast to standard H. pylori treatment was reported to reduce side effects such as nausea, diarrhea and abdominal pain, and to raise eradication rates, compared with standard treatment alone.DYNAMICS OF GASTRIN LEVEL IN PATIENTS WITH DIABETES MELLITUS 2 TYPE AND CHRONIC GASTRITIS AFTER HELICOBACTER PYLORI ERAD…
- In 53 adults with diarrhea-predominant irritable bowel syndrome, 200 mg of Saccharomyces boulardii three times daily for 30 days lowered symptom scores, though it helped less than mesalazine alone.Treatment of diarrhea-predominant irritable bowel syndrome with mesalazine and/or Saccharomyces boulardii.
- In 40 people with systemic sclerosis and bacterial overgrowth, S. boulardii alone or with metronidazole for 2 months reduced diarrhea, abdominal pain and gas, while metronidazole alone did not.Effectiveness of Saccharomyces boulardii and Metronidazole for Small Intestinal Bacterial Overgrowth in Systemic Scleros…
- In 39 airline pilots with chronic stomach inflammation, a four-week course of a Saccharomyces boulardii and Enterococcus faecium capsule reduced stomach pain and bloating more than watchful waiting did.Probiotic Supplementation With Saccharomyces boulardii and Enterococcus faecium Improves Gastric Pain and Bloating in Ai…
- In 26 people with irritable bowel syndrome, a four-strain probiotic capsule including Saccharomyces boulardii taken for 30 days reduced symptom scores, with the largest benefit in those who also had bacterial overgrowth in the small intestine.Effect of a Preparation of Four Probiotics on Symptoms of Patients with Irritable Bowel Syndrome: Association with Intes…
- In 25 adults with acute diarrhea, 5 billion CFU of Saccharomyces boulardii strain Unique 28 twice daily for 10 days cut diarrhea duration, stool frequency and abdominal pain, with no safety concerns.Oral consumption of potential probiotic Saccharomyces boulardii strain Unique 28 in patients with acute diarrhoea: a cli…
- In a large European registry of about 70,000 Helicobacter pylori treatments, adding Saccharomyces boulardii was linked to fewer side effects, including diarrhea, and to better eradication when combined with clarithromycin, amoxicillin and metronidazole.Real-World Effectiveness and Safety of Saccharomyces boulardii CNCM I-745 as Adjunct Therapy for Helicobacter pylori Era…
- In 141 patients with a med-related gut imbalance, a 10 to 14 day course of Saccharomyces boulardii was followed by fewer stools, less flatulence and less abdominal pain in 92.9% of them.Read the study on PubMed (34459767) →
Review Totals and Summary
Members Only1,601 reviews · 92% positive
Thorne Sacro-B capsules are very well liked across the stores that sell them, with about 676 ratings in total and almost no criticism. Buyers mostly use it for gut problems, yeast overgrowth and recovery after meds. I left out reviews of other forms of the product and covered the capsules only. **What buyers say it did for them:** The strongest reports are about digestion. One person with long-standing IBS-D, who had been taking Imodium almost daily, said "my symptoms have almost disappeared" after a few weeks of one capsule a day. Another uses it for loose stools and says it "always helps my digestion get back on track." Others describe help with leaky gut, and one simply said "I have my life back." Yeast and candida come up often. One reviewer said "No more yeast buildup and discomfort," and another reported great improvement in oral thrush. One Vitacost reviewer said it helped stop a stomach bug within a day or two. **meds and travel:** Recovery after meds is a common theme. One buyer took meds for almost a month and "did not develop intestinal problems or a yeast infection." Another said it was effective in getting their digestion back on track. Some use it when traveling, calling it "an extra layer of protection" for unfamiliar food and water. **Convenience, taste and form:** The main practical point is that it needs no refrigeration, which buyers value for shipping, summer heat and trips. Vitacost reviewers say the capsules are easy to swallow and easy to take, and one called the packaging and ease of use excellent. Nobody mentions taste or smell, and no store page reports problems with capsule size. **What buyers complain about:** Nothing substantive. The store summaries say no reviewer complained about the capsules, taste, price, bottle or side effects. The only sign of any lower rating is on the Thorne page, where the star breakdown shows three three-star ratings and one four-star alongside 26 five-star ratings, but no written complaint explains them. The review texts also come from a small sample of the total ratings, and several are one-liners, so detail is limited. **Value for money:** Price gets little attention. One four-star reviewer called it a "Solid product. Decent price. Usually in stock." No one calls it overpriced. Some buyers say they trust Thorne's reputation, and one said they would stay a customer "for as long as Thorne produces it." **Who it seems to suit:** It appears to suit people dealing with IBS-type symptoms, loose stools, suspected leaky gut, candida or yeast problems, and those taking meds. It also suits travelers and anyone who wants a probiotic that doesn't need the fridge. Several buyers took it on the advice of a nutritionist, naturopath or functional doctor. Vitacost reviewers also mention urinary tract infections and small intestinal bacterial overgrowth. No group is reported as unsuited to it, though results are individual and reviewers hoped their improvements would last.
Biohacker Summary
Members Only3 of 10 recommend it
Four of the ten panelists spoke about Saccharomyces boulardii, the main ingredient, and most of them recommend or use it. They take it mainly to crowd out yeast overgrowth, break down the protective film around candida, calm the gut, and raise gut immune defenses, and two also mention it for diarrhea and for clearing unwanted gut bugs. Several advise taking it daily during a course of meds and for a few weeks afterward, because it holds up well and helps limit gut changes. One panelist pairs it with another gut product and another suggests adding it to certain probiotics. No one gave a dose or reported stopping, and the one panelist whose latest view is neutral simply called it a good fungus.
See all 4 biohackers →Hide the biohackers
Dr. Mark Hyman · Saccharomyces boulardii · recommends
- Recommends Saccharomyces boulardii as especially important when meds are being taken because it helps reduce yeast overgrowth and rebuild the gut.
- Recommends Saccharomyces boulardii, a specific probiotic, to help lower levels of beta glucuronidase and the bacteria producing it in the gut, which can contribute to endometriosis.
- Recommends Saccharomyces boulardii, a yeast that acts like a peacekeeper in the gut, regulating the colony, getting rid of candida, and bringing balance to the gut, especially to the anaerobes. It also gets rid of bad parasites and H. pylori, and has been used with babies and children for 50 years to stop diarrhea.
- Uses Saccharomyces boulardii, a yeast against yeast, to help with yeast overgrowth.
- Recommends utilizing Saccharomyces boulardii, a beneficial yeast, to raise secretory IgA response, which can make one more resilient to stress, help overcome food sensitivities, and clear pathogens from the gut.
- Recommends Saccharomyces boulardii, a powerful yeast against yeast, as a very effective supplement, specifically mentioning a product called Biome-Ohm because it also has compounds that help break up the biofilm where yeasts live in the gut.
- Mentions that Saccharomyces boulardii is a bacterial species that is often in low concentration in patients with inflammatory bowel disease, and replacing it provides huge benefits.
- Mentions Saccharomyces boulardii as a bacterial species that is often missing or in low concentration in patients with inflammatory bowel disease, and replacing it can lead to huge benefits.
- Recommends Saccharomyces boulardii for killing yeast in the gut, noting it does a brutal job and can cause symptoms as toxins are released.
- Recommends Saccharomyces boulardii as a yeast that kills other yeasts, stating it's a potent killer and can be found at health food stores. He notes that if it causes negative symptoms, it means it's working.
Dr. Eric Berg · Saccharomyces boulardii · recommends
- Recommends Saccharomyces boulardii to destroy biofilms associated with candida overgrowth.
- Recommends Saccharomyces boulardii as the single most powerful thing to start dismantling the Candida biofilm, as it produces powerful enzymes that break down this protective barrier.
- Recommends Saccharomyces boulardii as a friendly yeast that can be added to certain probiotics.
Dave Asprey · Saccharomyces boulardii · uses
- Notes that the guest is taking Saccharomyces Boulardii, a probiotic yeast that feeds on candida, which he used for years.
- Notes that Saccharomyces Boulardii is a species of yeast that eats bad yeast like candida, reduces autoimmunity, and is something he has used in home fermentation and taken orally to help with leaky gut.
- Recommends taking Saccharomyces boulardii daily during and for a few weeks after a course of meds to help relieve diarrhea and mitigate negative microbiome changes.
- Notes that the member is taking Saccharomyces boulardii, a probiotic yeast that feeds on candida, which Dave Asprey used for years as a sign of treating candida.
Ben Greenfield · Saccharomyces boulardii · neutral
- Mentions that Saccharomyces boulardii is a good fungus.
- Uses Saccharomyces boulardii when a patient is getting a med.
- Mentions that a colleague had better results combining Saccharomyces boulardii with Atrantil, and research shows it can increase secretory IgA, making it a helpful combination.
- Uses Saccharomyces boulardii (a yeast) to kill bad bugs and ensure only good bugs grow in a healthy gut environment.
- Recommends taking a probiotic supplement that specifically contains saccharomyces boulardii, as this strain can better withstand meds and should be continued after a med course.
- Recommends adding Designs for Health Saccharomyces boulardii, abbreviated S-boulardii, to a probiotic regimen, especially for those who have been on meds or had their appendix removed.
RAL Summary
Members OnlyTier 2 for Digestion and Bloating
Large human reviews show this yeast clearly reduces bloating and constipation during a med treatment and eases abdominal pain in irritable bowel syndrome [1][5], and 92% of 1,605 reviews are positive, which meets the tier 2 rule.
Where the evidence disagrees: 4 of the 31 human studies found no effect.
More Details
Members OnlyBody systems · Combine with · Possible side effects
Body systems: Digestive system, Immune system
Combine with: Sacro-B pairs Saccharomyces boulardii, a beneficial probiotic yeast, with Bacillus subtilis, a spore-forming probiotic, to support gut flora balance, stool consistency, and digestive comfort. It stacks well with a prebiotic fiber such as partially hydrolyzed guar gum or acacia fiber to feed beneficial bacteria. A Lactobacillus/Bifidobacterium multi-strain probiotic adds complementary strain diversity. A broad-spectrum digestive enzyme blend with meals may reduce occasional gas and bloating from poorly digested food. L-glutamine, zinc carnosine, or aloe/DGL can support the integrity of the gut lining. Peppermint oil capsules (enteric-coated) may ease occasional cramping and bloating, and magnesium can help with irregularity. Take S. boulardii consistently, and separate it from antifungal medications. Consult a clinician if symptoms are persistent, severe, or if you are immunocompromised.
Possible side effects: No major side effects reported; in irritable bowel syndrome trials side effects were no more common than with controls.
Supplement Facts
Saccharomyces boulardii 250 mg
| Saccharomyces boulardii | 250 mg | † |
Other ingredients: Beet Fiber, Hydroxypropyl Methylcellulose, Pectin, Water, Calcium Laurate, Medium Chain Triglycerides.
Directions: Suggested use: Take 1 capsule one to three times daily between meals or as recommended by your health-care practitioner.
Barcode (UPC) 693749757030 · Label source: NIH label database · Report a label change
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- How to Improve Gut Health Naturally: Fiber, Foods and the Probiotic Strains With Human TrialsArticle · Sep 15, 2026
- Best Probiotic for Bloating: The Strains With Human Trials, and How to Choose OneArticle · Oct 27, 2026
Graded November 5, 2026 by the Reverse Age Lab evidence engine, from human studies, real reviews and our biohacker panel. How we grade. Is this medical advice? No. Rala organizes the published evidence; go over any change with your doctor, especially if you take meds.
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