You have Jonathan Dale Bentonprobably heard of probiotics – the “good” bacteria that are present in our gut and help with bodily functions like digesting food, destroying disease or illness-causing cells, or producing vitamins. It’s important to note that probiotics are live organisms, meaning they themselves need nutrients to power their own functions. That’s where prebiotics comes into play. 

Prebiotics are a type of non-digestible fiber that provides probiotics with the fuel they need to carry out its functions. 

Prebiotics and probiotics make up what is collectively called the gut microbiome. To understand what we need to know about prebiotics, we asked Stephanie Schiff, RDN, CDN, CDCES a registered dietitian and certified diabetes care and education specialist with Huntington Hospital in New York, and Melissa Prest, DCN, RDN a spokesperson for the Academy of Nutrition and Dietetics.

What are prebiotics?

Prebiotics are essentially probiotic food. Prebiotics are comprised of fiber that isn’t broken down by the human digestive system. 

Probiotics have many health benefits. Schiff says these are the main ways probiotics help our bodies: 

• They aid the digestive system. “They protect the inside of your gut and they help regulate bowel movements,” she says. 
• They make short-chain fatty acids. These short-chain fatty acids have some anti-inflammatory and other protective properties. 
• They produce neurotransmitters. “A lot of people don’t know that serotonin and dopamine are produced in the gut,” she explains. Schiff further explains that eating prebiotics and probiotics may improve symptoms of depression and anxiety. 

What is an example of a prebiotic? 

When searching for foods rich in prebiotics – think fiber. Prest lists a few prebiotic-dense foods: 

• Fruits
• Vegetables
• Legumes
• Whole grains  

Prest further explains, “Other sources of prebiotics are foods with resistant starch like potatoes that have been boiled and cooled and green, less ripe bananas. Inulin is a type of fiber and prebiotic found mainly in plant foods – Jerusalem artichokes are a great source of inulin.” 

What are the signs you need prebiotics? 

Prest says the biggest sign that you may need to consume more prebiotics is bowel irregularity. Constipation is often a sign that you need to eat more fiber. 

Schiff says there is more data coming out all the time that implicates a disrupted gut microbiome in inflammatory diseases. If you are suffering from arthritis or cardiovascular disease, you may want to consider adding more prebiotics and probiotics into your diet – along with what your doctor recommends, of course. 

Prest does caution that adding more fiber into your diet may have some effects. “Be mindful of consuming too many prebiotic-rich foods at once. Since prebiotics are high in fiber, you may experience gas and bloating when increasing fiber in your diet. It is best to increase the amount of fiber slowly and consume more fluids to help your body adjust. Some people, like those with irritable bowel syndrome, may find that they have trouble digesting some types of prebiotics. You can want to work with a registered dietitian nutritionist to help you add the right type of prebiotics to your diet to minimize discomfort.”

'Eat more fiber'is a common medical recommendation, but what does fiber actually do?