A randomised, double-blind, placebo-controlled trial involving 443 people with Irritable Bowel Syndrome (IBS) tested the effects of an oral heat-inactivated Bifidobacterium bifidum MIMBb75 supplement. The results showed that this postbiotic significantly reduced IBS symptoms, including abdominal pain, bloating, and irregular bowel movements, compared to a placebo (source)
What Are Postbiotics?
What Are Postbiotics? A Comprehensive Guide to the New Frontier in Gut Health
In the world of gut health, most people are familiar with probiotics—the “good bacteria” that promote a healthy digestive system—and prebiotics, the fiber-rich foods that nourish these beneficial microbes. But there’s a new player in the gut health game that’s gaining attention for its remarkable potential: postbiotics.
While probiotics have long been the stars of the microbiome conversation, postbiotics are emerging as powerful compounds that may offer many of the same benefits—without some of the limitations associated with live bacteria. But what exactly are postbiotics? How do they work? And why are they considered the next big thing in health and wellness?
This blog will dive deep into the world of postbiotics, exploring:
- What postbiotics are
- How they differ from probiotics and prebiotics
- The science behind their health benefits
- Sources of postbiotics
- Potential applications in health and disease
- Safety considerations and future prospects
- Recommended products
What Are Postbiotics?
Simply put, postbiotics are the bioactive compounds produced by beneficial bacteria after they’ve consumed prebiotics and completed their life cycle. Unlike probiotics, which are live microorganisms, postbiotics are the metabolic byproducts or “waste” products of these microbes—but don’t be fooled by the term “waste.” These compounds are far from useless; in fact, they play critical roles in promoting health (source).
Postbiotics can include:
- Supernatants: Certain probiotic bacteria, like Lactobacillus acidophilus and Lactobacillus casei, produce substances that help reduce inflammation and protect cells from damage. These beneficial compounds:
- Lower inflammation by reducing levels of TNF-α, a pro-inflammatory chemical.
- Boost anti-inflammatory responses by increasing IL-10, which helps calm the immune system.
- Act as antioxidants, helping to protect gut cells from oxidative stress.
- Additionally, compounds from L. casei and Lactobacillus rhamnosus GG have been shown to prevent the invasion of colon cancer cells. Since these probiotic-derived substances can both reduce oxidative stress and directly fight cancer cells, they may have potential in cancer prevention and gut health.
- Short-chain fatty acids (SCFAs) like butyrate, acetate, and propionate. Read our blog all about butyrate here.
- Enzymes
- Peptides
- Cell wall fragments (like lipoteichoic acids from bacteria)
- Polysaccharides
- Vitamins (such as B vitamins and vitamin K)
- Organic acids
- Antioxidants
The International Scientific Association for Probiotics and Prebiotics (ISAPP) defines postbiotics as (source):
“A preparation of inanimate microorganisms and/or their components that confers a health benefit on the host.”
This definition highlights an important point—postbiotics are not live bacteria. They are the beneficial compounds produced by bacteria, which can still provide health benefits even though the bacteria themselves are no longer alive (source).
Postbiotics vs. Probiotics vs. Prebiotics: What’s the Difference?
To fully understand postbiotics, it’s helpful to see how they fit into the broader landscape of gut health:
- Probiotics = Live microorganisms (like certain strains of Lactobacillus or Bifidobacterium) that, when consumed in adequate amounts, offer health benefits.
- Prebiotics = Non-digestible fibers (like inulin and fructooligosaccharides) that serve as food for probiotics, helping them grow and thrive.
- Postbiotics = Non-living byproducts created when probiotics consume prebiotics. These compounds can have direct health benefits on their own.
Think of it like this:
- Prebiotics are the ingredients (like flour, sugar, and eggs),
- Probiotics are the chefs who use these ingredients,
- Postbiotics are the finished dish—the final product that nourishes your body.
How Do Postbiotics Work? The Science Behind the Benefits
Three underlying mechanisms driving the efficacy of postbiotics include protective modulation against pathogens, enhancement of the epithelial barrier and the modulation of inflammatory and immune responses, respectively. (source)
Here are some of the key mechanisms:
🔬 1. Strengthening the Gut Barrier
The intestinal barrier acts as a gatekeeper, allowing nutrients to pass into the bloodstream while keeping harmful substances out. Postbiotics like butyrate (a type of short-chain fatty acid) help (source):
- Tighten the junctions between gut cells, reducing “leaky gut”
- Promote the growth of mucus-secreting cells that protect the gut lining
- Support the health of colonocytes (cells that line the colon)
🦠 2. Modulating the Immune System
They can influence immune function (source) by:
- Reducing inflammation through the suppression of pro-inflammatory cytokines
- Stimulating the production of regulatory T cells that keep the immune system balanced
- Enhancing the activity of antimicrobial peptides that defend against harmful pathogens
⚡ 3. Anti-Microbial Properties
Some postbiotics produce substances like bacteriocins—natural compounds that help fight off harmful bacteria, viruses, and fungi. These antimicrobial effects can prevent infections and support a healthy microbial balance (source).
🧠 4. Gut-Brain Axis Communication
Emerging research suggests they may influence the gut-brain axis, the complex communication network between the gut and the brain. Certain postbiotic metabolites can:
- Affect mood and behaviour
- Regulate neurotransmitter production (like serotonin)
- Reduce anxiety and depression-related symptoms
🏃 5. Metabolic Benefits
They play a role in:
- Regulating blood sugar levels
- Improving insulin sensitivity
- Reducing cholesterol levels
Health Benefits of Postbiotics
Postbiotics are being studied for their potential to support a wide range of health conditions (source):
✅ 1. Digestive Health
- Irritable Bowel Syndrome (IBS): Postbiotics can reduce symptoms like bloating, gas, and diarrhoea.
- Inflammatory Bowel Diseases (IBD): By reducing gut inflammation, postbiotics may help manage conditions like ulcerative colitis and Crohn’s disease.
- Diarrhoea: Some postbiotics have been shown to shorten the duration of infectious diarrhoea, especially in children.
❤️ 2. Immune Support
- Enhanced immune response against pathogens
- Reduced allergic reactions
- Potential to help in managing autoimmune conditions
Postbiotics could play a role in preventing and managing SARS-CoV-2 (COVID-19) since the gut microbiome’s composition and activity may influence biomarkers linked to severe COVID-19 outcomes. Maintaining a healthy gut environment with postbiotics may help support immune function and reduce the risk of complications (source).
🍎 3. Metabolic Health
- Improved glucose metabolism
- Lower cholesterol and triglyceride levels
- Support for healthy weight management
🧠 4. Mental Health
- Potential to reduce symptoms of anxiety and depression
- Support for cognitive function through gut-brain axis modulation
👶 5. Infant and Child Health
- Prevention and management of necrotising enterocolitis (a serious condition in premature infants)
- Support for healthy immune development (source).
Sources of Postbiotics
They can be obtained from:
- Fermented Foods:
- Yogurt
- Kefir
- Sauerkraut
- Kimchi
- Miso
- Tempeh
- Kombucha
These foods contain both live probiotics and the postbiotic compounds produced during fermentation.
- Postbiotic Supplements:
- Some products contain purified postbiotic extracts (like heat-killed bacteria or isolated short-chain fatty acids) without live microbes.
- Naturally Produced in the Gut:
- When you consume fiber-rich prebiotics, your gut bacteria naturally produce postbiotics as part of their metabolic process. For example the prebiotic PHGG supports butyrate production, a postbiotic.
Are Postbiotics Safer Than Probiotics?
One of the key advantages is their safety profile, especially for individuals who may be at risk from live probiotics, such as:
- Immunocompromised individuals
- Those with critical illnesses
- People with leaky gut or severe inflammation
Since postbiotics don’t contain live bacteria, there’s no risk of infection or overgrowth, making them a promising option for vulnerable populations.
Postbiotics in Clinical Research
Research on postbiotics is still in its early stages, but clinical trials are showing promising results:
- A 2024 study found that supplementation significantly reduced symptoms of IBS (source).
- A 2022 study found a postbiotic product of oat gruel fermented with Lactobacillus plantarum 299v helped with leaky gut (source).
- In infants, they have been used to prevent diarrhoea and improve immune responses with fewer side effects than traditional probiotics.
- Ongoing research is exploring postbiotics for conditions like obesity, diabetes, eczema, and even neurological disorders.
Potential Side Effects and Considerations
While they are generally considered safe, potential side effects can include:
- Digestive discomfort (such as gas or bloating) when starting supplements
- Allergic reactions in rare cases, depending on the source
Always consult with a healthcare professional before starting any new supplement, especially if you have a medical condition or are pregnant or breastfeeding.
The Future of Postbiotics
The future looks promising, with potential applications in:
- Personalised medicine, tailoring postbiotic therapies to individual microbiome profiles
- Functional foods fortified with postbiotic compounds
- Targeted therapies for chronic diseases, including metabolic and autoimmune disorders
As science continues to uncover the complex relationship between the microbiome and human health, they may become a cornerstone of future health strategies.
Recommended Products
- Butyrate – a short chain fatty acid shown to support the gut microbiome and gut lining.
- PHGG – a prebiotic that supports butyrate production.
- Daily Microbiome Booster – combines precision prebiotics, next generation postbiotics and bioactive collagen peptides.
Key Takeaways
- Postbiotics are the beneficial compounds produced by probiotics during fermentation.
- They include substances like short-chain fatty acids, enzymes, and cell wall fragments that can support gut health, immunity, and more.
- Unlike probiotics, they are non-living, making them safer for certain populations.
- They’re found naturally in fermented foods and are available as supplements.
- While research is still evolving, they hold great promise for a variety of health conditions.
If you’re looking to support your gut health but are hesitant about probiotics—or if you simply want to explore new options—they might be the next big thing to add to your wellness routine.
