The 'biotics' explained: Your ultimate guide to prebiotics, probiotics, and postbiotics
Written by: Alba Health team
Last updated: 2025-11-11
Summary
It’s easy to get lost in the “biotic” buzzwords – probiotics, prebiotics, postbiotics. But each plays a unique role in keeping your gut ecosystem balanced. Probiotics are the friendly bacteria, prebiotics are the fibers that feed them, and postbiotics are the beneficial compounds they produce. Together, they form the foundation of gut and overall health – for both children and adults.
Probiotic, prebiotic, postbiotic – it’s easy to get lost in the "biotic" buzzwords. You might be wondering if your child needs a specific yogurt for their digestion, or if a supplement you saw online could help your own energy levels.
These terms all describe different, but related, parts of a healthy gut microbiome: the community of trillions of bacteria and other microbes living in your gut. Understanding what they are helps you make practical, informed choices for your family's wellness.
What they are and why they matter
The easiest way to think about your gut microbiome is as a busy garden inside your body. For this garden to flourish, it needs three things: the right seeds (probiotics), good fertilizer (prebiotics), and the healthy fruit and flowers that grow as a result (postbiotics).
Probiotics: The seeds or plants
Probiotics are the "friendly bacteria" themselves. They are live microorganisms that, when present in the right amounts, provide a health benefit.
- What they do: These beneficial microbes help digest food, support your immune system, produce vitamins, and compete for space with less helpful microbes.
- Key examples: Common probiotic groups you’ve likely heard of include Lactobacillus and Bifidobacteria. Bifidobacteria are especially important in the early-life window for infants.
Prebiotics: The fertilizer
Prebiotics are the food for your friendly bacteria. Specifically, they are types of dietary fiber that your human cells can't digest.
- What they do:Prebiotics travel safely through your stomach and small intestine. When they reach your colon, your gut bacteria (probiotics) feast on them. This food allows the beneficial microbes to grow, multiply, and do their important jobs.
- Key examples: You get prebiotics from fiber-rich foods like onions, garlic, bananas, oats, and asparagus.
Postbiotics: The fruit and flowers
Postbiotics are the beneficial compounds that are produced by probiotics when they eat (ferment) prebiotics.
- What they do: This is the "output" that does much of the heavy lifting for your health. These compounds include Short-Chain Fatty Acids (SCFAs) like butyrate, as well as vitamins and other signaling molecules. SCFAs are critical: they provide energy for your gut lining, help maintain the gut barrier, and are associated with supporting the immune system.
- Key examples: SCFAs, enzymes, and fragments of beneficial bacteria.
Sources or options
You don't necessarily need expensive, complex supplements to support your gut garden. You can find prebiotics and probiotics in everyday foods.
To get probiotics: Look for fermented foods that contain live, active cultures. Good options include:
- Yogurt (check the label for "live cultures")
- Kefir (a fermented milk drink)
- Sauerkraut (unpasteurized)
- Kimchi
- Miso
To get prebiotics: Focus on high-fiber foods. Variety is key, as different bacteria like different types of fiber. Good options include:
- Garlic, onions, and leeks
- Asparagus
- Bananas (especially slightly green ones)
- Whole oats
- Apples
- Jerusalem artichokes
To get postbiotics: Your body’s own microbiome is the best postbiotic factory. By consuming prebiotic-rich foods, you give your probiotics the fuel they need to produce postbiotics naturally. Some fermented foods, like kefir, may also contain postbiotics created during the fermentation process.
How to tailor your approach
There isn't a simple daily dose for these "biotics." The goal isn't just more bacteria; it's more diversity and balance.
A simple way to think about it: A healthy gut plan follows a simple equation:
Prebiotics (Diverse Foods) + Probiotics (Diverse Microbes) = Healthy Postbiotics (Beneficial Products)
Worked example (The "gut garden" analogy): If you only plant one type of seed (a single probiotic strain) and only use one type of fertilizer (a single prebiotic fiber), you’ll get a very limited garden. A healthy gut thrives on variety.
When food isn't enough: Finding your focus
For most people, a diverse, fiber-rich diet is the best foundation. But sometimes, your "gut garden" might need more specific help. Modern exposures – like C-section births, antibiotic use, or a less-diverse diet – can mean that important friendly bacteria are at low levels.
This is where a "one-size-fits-all" approach often falls short. Instead of guessing which supplement to buy, the first step is to understand your unique patterns. A microbiome test, like Alba Health's, can help identify if your gut patterns show low levels of key friendly bacteria (like Bifidobacteria) or groups that produce important postbiotics (like butyrate producers).
These insights allows you to get a personalized, evidence-backed plan. With support from a Certified Nutrition Coach, you can move from guessing to focusing on the right steps for you or your child – whether that's specific prebiotic foods or, if appropriate, particular evidence-backed probiotic strains.
Tailoring for life stages
- For parents:The goal for children (0-13) is often about building a strong foundation. This means focusing on introducing a variety of plant fibers (prebiotics) to feed their developing microbiome. Adding kid-friendly fermented foods like yogurt or kefir can introduce beneficial microbes (probiotics).
- For adults: For adults (18+), the focus may be on maintaining resilience, regularity, and energy. This often means increasing the diversity of prebiotic fibers (e.Example: aiming for 30+ different plant types per week) and rotating different fermented foods to support a robust community of SCFA producers.
Edge cases, myths, and supplements
Myth: All probiotics are the same
This is one of the biggest misconceptions. Probiotic benefits are strain-specific. The specific strain Lactobacillus reuteri DSM 17938, which has been studied for its association with infant comfort, is different from strains studied for adult immune support. You can't expect one "general" probiotic to do every job. This is why Alba's guidance is careful to suggest specific strains based on individual test results and scientific evidence.
Myth: You must take a supplement for all three
For most healthy people, a diverse, fiber-rich diet is the best and most sustainable way to support all three "biotics". Supplements can be helpful, but as mentioned, it's hard to know what you need without understanding your gut's starting point.
Edge Case: What about after antibiotics?
Antibiotics are often necessary, but they can't tell the difference between harmful bacteria and the friendly ones. This can lead to a reduction in gut diversity. This is a key time when a personalized plan to support the gut with prebiotic foods and, potentially, specific evidence-backed probiotics may be helpful for both children and adults.
Summary
Here’s the simple takeaway:
- Probiotics are the live, friendly bacteria in your gut (the "seeds"). You get them from fermented foods like yogurt and kefir.
- Prebiotics are the fiber-rich foods that feed your bacteria (the "fertilizer"). You get them from foods like oats, onions, garlic, and bananas.
- Postbiotics are the beneficial compounds your bacteria produce when they eat prebiotics (the "fruit"). These include vital SCFAs like butyrate.
- Focus on food first: A diverse diet rich in different plant fibers and fermented foods is the best way to support your "gut garden."
- Strain matters: If you do look for a probiotic supplement, remember that benefits are strain-specific.
- Personalization helps: Understanding your own unique gut patterns with a test like Alba's can help you move from guessing to a clear, actionable plan.
- Gibson GR et al. 2017. The concept of the prebiotic revisited: The ISAPP consensus definition and scope. Nat Rev Gastroenterol Hepatol.
- Hill C et al. 2014. Expert consensus document: The International Scientific Association for Probiotics and Prebiotics consensus statement on the scope and appropriate use of the term probiotic. Nat Rev Gastroenterol Hepatol.
- Roberfroid M et al. 2010. Prebiotic effects: metabolic and health benefits. Br J Nutr.
- Scott KP et al. 2013. The influence of diet on the gut microbiota.Pharmacol Res.
- Ríos-Covián D et al. 2016. Intestinal short chain fatty acids and their link with diet and human health. Front Microbiol.
- Ouwehand AC et al. 2002. Probiotic and other functional microbes: from markets to mechanisms. *Curr Opin Bi
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