What are Postbiotics?
Jazmin Anderson
| 3 min read
Key Takeaways
- Postbiotics are non‑living compounds created by microbes during fermentation, such as short‑chain fatty acids, peptides and vitamins, that can be isolated for use in supplements.
- A 2025 review found postbiotics may be a more stable alternative to probiotics, offering antioxidant, anti‑inflammatory, blood‑sugar and immune‑modulating benefits, particularly for immunocompromised or vulnerable patients.
- Eating fermented foods like kefir, tempeh and kimchi can increase the body’s natural postbiotic production, while most supplements are not FDA‑regulated and should be used only under professional guidance.
Gut health is a popular topic, with most conversations focusing on prebiotics and probiotics.
However, there is a third, less-discussed “biotic” called postbiotics. Here's some information about how postbiotics contribute to a healthy digestive system.
What are postbiotics?
Postbiotics are beneficial compounds produced by microbes as they ferment food or carry out normal metabolic activities. They aren’t living organisms but the byproducts of microbial activity.
When they’re artificially produced for use in supplements, manufacturers produce postbiotics through microbial fermentation, a biochemical process in which microbes like bacteria, yeasts and molds break down nutrients in the absence of oxygen. After fermentation, manufacturers recover and process the broth through various chemical and physical processes depending on the desired compounds.
Postbiotics are made up of compounds that work together, such as:
- Short-chain fatty acids (SCFAs)
- Organic acids
- Peptides and bacteriocins
- Enzymes
- Exopolysaccharides and other polysaccharides
- Peptidoglycans
- Teichoic acids
- Cell-wall fragments
- Vitamins and other microbial metabolites
- Gamma-aminobutyric acid (GABA)
What are the benefits of postbiotics
A 2025 review of postbiotics suggests they may serve as a safer alternative to probiotics for immunocompromised people, premature infants or people with impaired gut barriers. Since postbiotics aren’t live organisms, they are described as more stable during processing and storage and potentially easier to standardize.
The review also explores the possible health benefits of postbiotics, which include:
- Antioxidant activity: Postbiotics may help counter oxidative stress through antioxidant enzymes. The review connects this to possible relevance for gut dysbiosis, inflammatory conditions, skin health and oxidative stress-related diseases.
- Anti-inflammatory effects: Some postbiotics have been shown in laboratory and early human studies to influence inflammatory signaling.
- Blood sugar support: Certain postbiotic compounds like SCFAs and GABA are being studied for their potential effects on glucose metabolism and insulin sensitivity.
- Anti-obesity and metabolic effects: Early research suggests postbiotics could possibly influence body weight, cholesterol metabolism, hunger regulation and gut microbiota composition.
- Immunomodulation: The review highlights postbiotics’ potential to influence immunity.
- Antihypertensive and cholesterol-related effects: SCFAs, exopolysaccharides, bacterial cell-wall components and other metabolites have a possible role in blood pressure regulation and bile acid excretion.
- Antimicrobial and antiproliferative effects: Postbiotics may contain compounds with antimicrobial properties.
While postbiotics can be beneficial, more research is needed to establish their efficacy, optimal formulations, dosing and long-term effects in humans.
Another 2025 review on the influence of postbiotics on the human gut microbiome suggests postbiotics may also have beneficial effects in several conditions associated with gut microbiome disruption, including:
- Inflammatory bowel disease (IBD)
- Irritable bowel syndrome (IBS)
- Obesity
- Constipation
Postbiotics vs. probiotics
Since postbiotics are not alive, a 2025 scientific article on probiotics stated they may provide these practical advantages over probiotics:
- Better stability during storage
- Longer shelf life
- More predictable composition
- Reduced risk of infection or bacterial translocation in vulnerable patients
Are supplements a good source of postbiotics?
The popularity of postbiotic supplements, especially Butyrate supplements, is on the rise, according to Stanford Medicine. Low butyrate production is often associated with diets low in fermentable fiber or with disruptions in the gut microbiome. In many cases, increasing dietary fiber may support the body’s natural production of butyrate.
It's also important to consider the safety and efficacy of the supplements. Most supplements are not regulated by the U.S. Food and Drug Administration (FDA), meaning they generally don’t undergo a review for effectiveness. Consider getting your biotic sources from food rather than supplementation, unless your physician or dietitian has recommended it.
Dietary habits in the long-term play a key role in the health of the gut microbiome. As our dietary habits improve, so does the microbiome, adapting and diversifying to create a strong and healthy ecosystem.
How to promote postbiotics production
According to Harvard Health, you can increase the amount of postbiotics in your system by increasing your intake of fermented foods, such as kefir, tempeh and kimchi. Consuming foods that promote a mix of healthy gut bacteria may help improve your overall health.
Photo credit: Getty Images
