What Are Postbiotics? Byproducts of Good Gut Bacteria

Postbiotics are the beneficial compounds, such as short-chain fatty acids, that are produced when probiotic bacteria consume prebiotic fibers in your gut. They are essentially the waste products of probiotics that support gut health.

What Postbiotics means

Postbiotics are the non-living byproducts created by live probiotic organisms in your gut. Unlike probiotics, they are not live bacteria. Instead, they are a mix of beneficial compounds that includes substances like short-chain fatty acids, enzymes, and fragments of microbial cells. These components are thought to be responsible for many of the health benefits associated with a balanced gut microbiome. The concept focuses on the results of bacterial activity rather than on the live bacteria themselves, representing a newer area of interest in nutrition science.

The relationship between prebiotics, probiotics, and postbiotics is a sequence. Prebiotics are types of fiber that act as food for beneficial gut bacteria, which are the probiotics. As these live probiotics break down and ferment prebiotic fibers, they produce postbiotics as a result. You can think of it as a simple chain: prebiotics are the fuel, probiotics are the factories, and postbiotics are the useful products that support your body, particularly the cells lining your gut.

You don’t typically consume postbiotics directly. Instead, you encourage your body to make them by nurturing your gut microbiome. A diet rich in prebiotic fiber from sources like whole grains, fruits, and vegetables provides the necessary fuel for your existing gut bacteria to create postbiotics. Fermented foods, like yogurt and kimchi, are valuable because they can contain both live probiotics and the postbiotics created during the fermentation process.

The science around postbiotics is still an emerging field. While the components of postbiotics, such as the short-chain fatty acid butyrate, are well-studied and known to be beneficial for gut health, the idea of taking a dedicated postbiotic supplement is relatively new. For now, the general focus remains on supporting your body’s natural production of them through a balanced diet rich in fiber and fermented foods. The specific effects and ideal amounts are still areas of active exploration.

How to Support Postbiotic Production

1. Eat more prebiotic-rich foods. These include garlic, onions, leeks, asparagus, bananas, and whole grains, which feed your beneficial gut bacteria.
2. Incorporate fermented foods into your diet. Foods like yogurt, kefir, sauerkraut, kimchi, and kombucha contain probiotics and may also contain postbiotics.
3. Aim for dietary diversity. Eating a wide variety of plant-based foods can help support a more diverse and resilient gut microbiome.
4. Stay well hydrated. Water is essential for overall digestive health and helps fiber do its job effectively in the gut.

Postbiotics vs. similar terms

Common misconceptions

• Myth: You need to take a postbiotic supplement. Your body naturally produces postbiotics when your gut bacteria digest prebiotic fiber. A diet rich in fiber-containing foods is the primary way to support this process.
• Myth: Postbiotics are just dead probiotics. While they are not live organisms, postbiotics are a complex mix of beneficial metabolic byproducts, like short-chain fatty acids and enzymes, created by live bacteria.
• Myth: More postbiotics are always better. The goal is to support a healthy, balanced gut microbiome that produces an appropriate amount of postbiotics for your body, not necessarily to maximize their production.

Related terms

• Gut Microbiome
• Probiotics
• Prebiotics
• Fermented Foods
• Fiber
• Soluble Fiber

How this entry was made: drafted with AI assistance from general, widely published definitions, checked in a separate verification pass for invented numbers and claims, and edited by the Millennials Wellness editors. General information only, not medical, financial or legal advice. Last checked October 2026. Our ground rules · Back to the glossary