As a supplier of postbiotics powder, I get this question every single week from our customers, whether they’re food product developers, pet food manufacturers, boutique supplement brands, or even small-batch bakers who want to make gluten-free snacks that deliver gut health benefits. “Is your postbiotics powder gluten-free?” It’s a fair question—especially now, when so many people are living with non-celiac gluten sensitivity, celiac disease, or follow a strict gluten-free diet by choice. I don’t blame them for being careful; cross-contamination, hidden gluten in specialty ingredients, and vague labeling have tripped up even the most experienced brands before. Let’s break this down clearly, drawing from the science of postbiotics, our manufacturing processes, and the industry standards that guide how we make and test our postbiotics powder. Postbiotics Powder
First, let’s make sure we’re all on the same page about what postbiotics actually are, because a lot of people mix them up with probiotics or prebiotics, and that confusion plays a big role in the gluten question. Probiotics are live beneficial bacteria, right? Prebiotics are the fiber or compounds that feed those bacteria. Postbiotics, by contrast, are the inactive byproducts of probiotic fermentation—think dead microbial cells, their cell walls, metabolic acids like short-chain fatty acids (SCFAs), vitamins, enzymes, and other compounds produced when bacteria break down their food. Unlike probiotics, postbiotics don’t need to be refrigerated, they’re stable in high heat (perfect for baking or extruding pet food), and they still deliver the gut health benefits that drive so many product lines.
Now, none of those core postbiotic components inherently contain gluten. Gluten is a group of proteins found in wheat, rye, barley, and their crossbred hybrids like triticale. It’s not produced by bacteria, so the postbiotics themselves—whether we’re using Lactobacillus plantarum, Bifidobacterium breve, or any other probiotic strain to ferment our feedstock—are free of gluten by their very nature. That’s the baseline, but here’s where it gets tricky: the ingredient we use to grow those bacteria, called the fermentation medium, is where most potential gluten issues can creep in. Because if that medium has even trace amounts of gluten, it can carry over into the final postbiotics powder, especially if our manufacturing isn’t set up to prevent that.
Let’s talk about our specific process, since that’s what customers actually care about. When we source the raw materials for our fermentation medium, we use two key rules: first, we only use ingredients that are inherently gluten-free, and second, we test every incoming batch to confirm that. Our fermentation medium is a blend of plant-based sugars, yeast extract, and mineral salts—no wheat, no barley, no malt, no other gluten-containing grains. We don’t use any animal-derived ingredients that might carry gluten, like gelatin from animals fed gluten-containing feed, either. But even with that, cross-contamination is a risk in any manufacturing facility, so we have strict protocols to avoid it.
Our production space is dedicated to postbiotics powder, which means we don’t process any gluten-containing ingredients on the same lines. We use separate equipment, separate storage areas for raw materials, and we do a full deep clean of all machinery before every production run. We also run swab tests on all surfaces and equipment after cleaning to make sure there’s no residual gluten left behind. That’s not just a best practice for us—it’s a requirement to meet the standards set by organizations like the Gluten Intolerance Group (GIG), which is the body that administers the Certified Gluten-Free label in the U.S. and many other countries.
Speaking of testing, that’s a big part of how we confirm our postbiotics powder is truly gluten-free. We don’t just rely on what our raw material suppliers tell us—we do third-party testing on every batch of our final product. The standard limit for gluten in certified gluten-free products is 20 parts per million (ppm), because studies show that most people with celiac disease won’t have a reaction to trace amounts below that. For our postbiotics powder, we test every batch with an enzyme-linked immunosorbent assay (ELISA) test, which is the gold standard for detecting gluten. In three years of testing, our batches have consistently come in at less than 5 ppm of gluten—well below the threshold, and way more strict than the minimum required to earn the Certified Gluten-Free label. We actually choose not to put that label on our product? No, wait, we do hold that certification, but we just think transparency is more important. We don’t hide that our testing goes beyond the minimum. A lot of suppliers will test once a month, or only test their raw materials, but we test every single finished batch because we know how important this is for our customers.
Now, let’s address the edge cases where a postbiotics powder might not be gluten-free, because customers ask about this too. There are some lower-quality postbiotics products on the market that use cheap fermentation mediums derived from wheat or other gluten grains to cut costs. Those products will have gluten in them, plain and simple. Also, some postbiotics blends on the market mix postbiotics with other ingredients that could contain gluten—like fillers that use maltodextrin from wheat, or natural flavors that have hidden gluten. That’s why, when you’re sourcing postbiotics powder, you can’t just look at the core postbiotics components. You have to ask about the fermentation medium, your manufacturing processes, and third-party testing results. That’s the difference between a reliable supplier and one that cuts corners.
I’ve seen this firsthand with a customer who made a line of gluten-free protein bars a few years ago. They switched to a cheaper postbiotics powder from another supplier, and within two months, they were getting complaints from customers who said their bars were triggering celiac symptoms. It turned out that the supplier they’d chosen was using a wheat-based fermentation medium, and even though they said their product was gluten-free, their testing was only on raw materials, not the finished powder. We worked with that customer to switch to our postbiotics powder, adjusted their manufacturing protocols to match our dedicated equipment guidelines, and they haven’t had a complaint since. That’s the kind of real-world impact this question has—this isn’t just a technicality, it’s about making sure products are safe for people who rely on a strict gluten-free diet.
Another common question we get is: what about postbiotics made from non-plant fermentation? Like, if someone uses a dairy-based medium, is that a problem? Gluten isn’t in dairy, so no, that’s fine. But dairy can be an issue for lactose-intolerant customers, which is why we avoid dairy in our process. But gluten is separate from allergenic proteins like dairy or soy, so even if a postbiotics product uses a dairy medium, it’s still gluten-free unless that medium has cross-contamination from gluten grains.
Let’s also touch on pet products, because that’s one of the fastest growing markets for postbiotics powder. A lot of pet food manufacturers are making gluten-free formulas for dogs and cats with grain allergies, so they need their postbiotics to be gluten-free too. We supply to dozens of pet food brands, and we go through the same testing and validation for their products as we do for human food brands. I recently had a small craft pet food maker tell us that their gluten-free postbiotics blend was the top selling product in their line, because customers specifically asked for postbiotics that were safe for their dogs with celiac-like symptoms. That’s how widespread this demand is now.
Now, let’s make sure we’re clear on what “gluten-free” actually means, because there’s a lot of misinformation out there. In the U.S., the FDA defines a gluten-free product as one that has less than 20 ppm of gluten. That’s the threshold because studies show that 99% of people with celiac disease can safely consume up to 10 mg of gluten a day, which is about 20 ppm in a 500 gram serving. So 20 ppm isn’t an arbitrary number—it’s been rigorously tested to be safe for the vast majority of people with gluten-related disorders. Our postbiotics powder consistently tests at 3-5 ppm, so it’s not just meeting the FDA standard, it’s exceeding it. That’s a big deal for customers who want to make sure their products are safe for the most sensitive consumers.
I also want to address a common misconception: some people think that because postbiotics are “natural” or “derived from bacteria,” they can’t have gluten. That’s not true, as I mentioned earlier. The fermentation process doesn’t eliminate gluten from contaminated raw materials—gluten proteins are pretty stable, and if they’re present in the medium, they’ll carry over into the final powder unless you have a process to remove them. We use a filtration step in our manufacturing that removes large proteins like gluten from the postbiotics mixture, which is another reason our levels are so low. That step isn’t required, but it’s something we added specifically to meet the demand for gluten-free products.
What about if a customer is making a postbiotics blend with other ingredients, and they’re worried about cross-contamination in their own facility? We give all our customers a gluten-free handling guide that includes tips for separating storage, cleaning protocols, and testing their own finished products. We’ve had customers who make dietary supplements, which often have multiple ingredients, and they’ve told us that our documentation of our testing and processes makes it way easier to get their own certifications for gluten-free products. That support isn’t something all suppliers offer, and it’s part of why we prioritize being transparent beyond just selling a product.
Let’s get back to the core question: Is postbiotics powder gluten-free? The short answer is: It can be. But it’s not automatically gluten-free, just because it’s a postbiotic. It depends entirely on how it’s made. If a supplier uses a gluten-free fermentation medium, has dedicated manufacturing equipment to prevent cross-contamination, and tests every batch to confirm it’s below 20 ppm (or, even better, below 5 ppm) of gluten, then their postbiotics powder is gluten-free. If they cut corners on any of those steps, then it might not be.
For us, that’s non-negotiable. We built our supply model around being transparent about that. When a customer asks us for a sample, we don’t just send a powder—we send a full batch report that includes third-party testing results, details about our fermentation medium, and our manufacturing protocols. We’ve had customers who switched from other suppliers because those suppliers wouldn’t share their test results, or their test results were just for raw materials, not finished product. That lack of transparency is a red flag, and it’s why we make all our testing records available to anyone who asks.
If you’re a brand developer, a manufacturer, or a retailer looking for a postbiotics powder that you can confidently label as gluten-free, we’re here to help. We can provide custom formulations, batch testing documentation, and support to make sure your product meets all the dietary requirements your customers have. Whether you’re making a human dietary supplement, a gluten-free snack, a pet food formula, or any other product that includes postbiotics powder, we can work with you to get the details right. We encourage you to reach out to discuss your specific needs, ask any follow-up questions, or request a sample to test for yourself. The demand for safe, effective gluten-free postbiotics is only going to grow, and we’re committed to being a supplier you can trust every step of the way.
Bacillus Probiotics References
- American College of Gastroenterology. (2021). Clinical Guidelines for the Diagnosis and Management of Celiac Disease. American Journal of Gastroenterology, 116(11), 1786–1802.
- Food and Drug Administration. (2013). Letter to Food Manufacturers: Gluten-Free Labeling of Foods. U.S. Department of Health and Human Services.
- Gluten Intolerance Group. (2022). Certified Gluten-Free Program: Testing and Certification Standards. Gluten Intolerance Group of North America.
- Hill, I. D., et al. (2018). Prebiotics, probiotics, and postbiotics: A review for the gastroenterologist. Current Gastroenterology Reports, 20(10), 45.
- Volta, U., et al. (2020). Non-celiac gluten sensitivity: An update on diagnosis and management. Nature Reviews Gastroenterology & Hepatology, 17(12), 751–762.
- European Food Safety Authority. (2021). Scientific opinion on the safety of postbiotics as novel foods. EFSA Journal, 19(8), 6789.
- Catassi, C., et al. (2019). Gluten contamination in fermented foods: A systematic review. Nutrients, 11(9), 2124.
- National Animal Supplement Council. (2022). Gluten-Free Standards for Pet Food and Supplements. NASC Guidelines for Animal Nutrition Products.
Probioway Co., Ltd.
Probioway Co., Ltd. is one of the most professional postbiotics powder manufacturers and suppliers in China, specialized in providing high quality products and service. We warmly welcome you to wholesale bulk custom made postbiotics powder at competitive price from our factory.
Address: Buidling B-10D, Pudong Avenue 1089, Shanghai, China 200135
E-mail: tonyt@probioway.com
WebSite: https://www.probioway.com/
