Understanding the Difference Between Prebiotics, Probiotics, and Postbiotics
Although their names sound similar, prebiotics, probiotics, and postbiotics each serve a unique role in supporting gut health. Together, they help maintain a balanced gut microbiome, which plays an important role in digestion, immune function, and overall wellness.
Prebiotics
Prebiotics are types of fiber and plant-based compounds that nourish beneficial bacteria already living in the gut. These nutrients are not digested by the body. Instead, they travel to the colon, where they are fermented by gut bacteria.
Prebiotics help support gut health by:
- Promoting the growth and activity of beneficial bacteria
- Supporting regular bowel movements and digestive comfort
- Helping to maintain the protective lining of the gut
- Encouraging the production of beneficial compounds, such as short-chain fatty acids
Common food sources of prebiotics include:
- Garlic, onions, and leeks
- Asparagus and artichokes
- Bananas
- Whole grains such as oats and barley
- Legumes, nuts, and seeds
When to focus on prebiotics
Prebiotics are most effective when consumed consistently as part of a fiber-rich diet. Gradually increasing intake may help reduce digestive discomfort, such as gas or bloating.
Probiotics
Probiotics are live, beneficial microorganisms that help maintain a healthy balance of bacteria in the digestive system. They are naturally present in the gut and can also be consumed through certain foods or supplements.
Probiotics may support health by:
- Helping to balance beneficial and harmful bacteria in the gut
- Supporting digestion and stool consistency
- Playing a role in immune system function
- Supporting gut health during times of stress, illness, or dietary changes
Natural food sources of probiotics include:
- Yogurt with live and active cultures
- Kefir
- Sauerkraut and kimchi (refrigerated varieties)
- Miso and tempeh
- Kombucha
What to know about probiotic supplements
The effects of probiotics vary by strain and individual. Not all probiotics offer the same benefits, and more is not always better. For many people, fermented foods are a gentle and effective way to support probiotic intake.
Postbiotics
Postbiotics are the beneficial compounds produced when probiotics break down prebiotics in the gut. These compounds include short-chain fatty acids, enzymes, peptides, and other bioactive substances that support gut and overall health.
Postbiotics help support the body by:
- Supporting the integrity of the gut lining
- Helping regulate inflammation
- Contributing to immune system balance
- Supporting metabolic and brain health
One of the most well-studied postbiotics is butyrate, a short-chain fatty acid that plays a key role in gut barrier health and anti-inflammatory processes.
How postbiotics are formed
Postbiotics are produced naturally when the diet includes enough fiber and fermented foods. Rather than focusing on supplements, supporting the gut’s natural production of postbiotics through diet is generally recommended.
How They Work Together
Prebiotics, probiotics, and postbiotics work as a connected system within the gut.
PIH Health Gastroenterologist Preeya Goyal says, “Prebiotics provide nourishment for beneficial bacteria, probiotics contribute helpful microorganisms, and postbiotics are the beneficial compounds created as those bacteria do their work. Eating a variety of fiber-rich plant foods along with fermented foods helps support all three, promoting a healthy and resilient gut microbiome," Dr. Goyal continues.
Prebiotics, probiotics, and postbiotics each play an important role in supporting a healthy gut, but they work best together as part of an overall balanced diet. For most people, regularly eating a variety of fiber-rich plant foods and fermented foods provides the foundation needed to support gut health and overall wellness.
If you’re experiencing ongoing digestive concerns or think you may not be getting enough of these nutrients through food alone, talk with your healthcare provider before starting any supplements. A provider can help determine what’s appropriate for your individual needs and health history. Find a PIH Health provider near you at PIHHealth.org/Doctors.
Preeya Goyal MD
Preeya Goyal MD is a fellowship-trained gastroenterologist with expertise in esophageal and anorectal motility, which focuses on how things move through the gastrointestinal tract. Dr. Goyal was attracted to gastroenterology very early in her medical training. She is a member of the American College of Gastroenterology, American Gastroenterological Association and American Society of Gastrointestinal Endoscopy. Dr. Goyal was born and raised in California and is very happy to have the opportunity to stay close to her large family. She enjoys traveling, tennis, dancing, painting, trying new restaurants and spending time with friends and family in her free time.
View Dr. Goyal's Profile
