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Prebiotics vs. Probiotics
Published on October 17, 2023
Written by Health Loft
understand the differences between prebiotic and probiotic

In an era of social media we hear a ton of buzz words thrown around related to health, one of those words might be probiotics. In order to gain a better understanding of what probiotics are, let’s break it down.

What Are Probiotics?

Though the word bacteria gets a bad rap, we have live bacteria that naturally populates our gastrointestinal tract, both good and bad. All together this bacteria makes up what we call our gut microbiome. This bacteria usually lives together in harmony to help protect us from disease and help us with digestion, but can be disrupted and cause an imbalance of good and bad bacteria which can lead to compromises in immunity and GI distress. Everyone’s gut microbiome is different. Luckily, it can be altered through controllable factors such as the diet.

A growing body of evidence shows the ability of probiotics to optimize health in various ways. Some of the proposed benefits include, reduced duration of acute diarrhea, reduced risk of antibiotic associated diarrhea, management of irritable bowel syndrome symptoms, improved cholesterol levels, and more recently improved usage of energy leading to decrease in waist circumference in some individuals. Probiotics have been most studied in the context of improving diarrhea symptoms, although they have also been linked to improvements in constipation. The effects of probiotics on gut health depends on what strain of bacteria it is, which species of bacteria are already present in the gut, and what region of the gut it is being absorbed in. There are billions of identified strains of probiotics. While scientists are beginning to connect specific bacteria strains to various health outcomes, guidelines are still in the making.

How to Incorporate Probiotics into your Diet.

The good news is that probiotics can be naturally obtained through the diet. They are primarily found in fermented foods such as yogurt, kombucha, sauerkraut, many cheeses, kimchi, tempeh, miso, pickles, and raw unfiltered apple cider vinegar. Some foods may be fortified with probiotics as well including some milks, juices, smoothies, cereals, nutrition bars, and infant and toddler formulas. The effects of these foods all depend on the level of probiotics present in the food during consumption, whether the food was processed before or after fermentation occurred, as well as the bacteria strain type. There are currently no dosage guidelines for probiotics, so to be sure you are getting enough, try and incorporate some or all of these foods into your daily routine!

Probiotics can also be obtained through supplements. That being said, going to the store and picking out a probiotic can be quite the feat. There are many probiotic supplements available on the market today in a wide variety of strains and doses which can be particularly confusing at the store. Currently, the FDA does not regulate dietary supplements, so it is hard to be certain you are getting the right one. The most common probiotics strains studied are: Lactobacillus, Bifidobacterium, Saccharomyces, Streptococcus, Enterococcus, Escherichia, and Bacillus. This information can be found on the supplement label on the back of the bottle. With current labeling requirements, supplement manufacturers are only required to list the total weight of the probiotics. This weight can include both dead and living microorganisms, but health benefits can only be obtained through the live bacteria. Manufacturing companies may also list the amount as CFU or colony forming units. They will be written as 1 x10^9 to indicate 1 billion, and so on and so forth. Supplements tend to be available in 1-50 billion CFUs, although a higher number does not necessarily translate to more health benefits.  Studies show that for health promotion, consuming 10-15 billion CFUs per day is recommended. To put into perspective, a container of yogurt contains between 1-10 billion CFUs for a standard portion, depending on the brand. For example, Activia yogurt has been shown to contain 5-10 billion CFUs per 4 oz. serving.

Probiotic supplements have been shown to be generally safe in healthy individuals. Any reported side effects tend to be mild GI distress such as gas. However, evidence is not as clear for individuals with compromised immune systems. After all, probiotics are live bacteria. Benefits and risks of probiotics should be discussed with a healthcare provider.


What Are Prebiotics?

While people have generally heard the term probiotic, prebiotics are discussed much less frequently. Since probiotics are live bacteria, they need fuel just like we do. Prebiotics are fermented soluble fibers that are broken down into short chain fatty acids and released into the bloodstream where they are used as fuel for probiotics. In other words, they serve as:


Food for Probiotics

While probiotics have a healthy backing of literature, much less research has been done on the effects of prebiotics on health. Aside from serving as fuel for our healthy gut bacteria, studies have linked prebiotics to improved immune function, improved cognitive function and reduced risk and severity of atopic dermatitis. They have been shown to have anti-inflammatory properties, which are beneficial to cardiovascular health. There is even some evidence linking prebiotics to improved calcium absorption as well. Prebiotics are generally considered safe to consume and any reported side effects tend to be mild GI distress such as gas or bloating.


How to Incorporate Prebiotics into your Diet

Prebiotics are primarily found in two types of complex carbohydrates known as fructo-oligosaccharides or FOS, and galacto oligosaccharides or GOS. Other prebiotics that we know of are derived from starches such as pectin found in many fruits and resistant starch found in whole grains, beans, peas and lentils. Prebiotics are naturally present in asparagus, leeks, garlic, chicory, onion, artichoke, wheat, honey, banana, barley, tomato, rye, soybean, human and cow’s milk, peas, beans, seaweeds and microalgae, etc.

Synbiotics are products that contain both prebiotics and probiotics in one pretty package. They are available commercially, but can be created at home by thoughtfully pairing foods.


Incorporating Synbiotics with Food at Home:

  • Try a breakfast:
    • 4 oz. yogurt topped with sliced banana
  • Try a side of miso soup:
    • Bring 2 cups broth of choice to a boil
    • Chop up 3 oz tempeh and add to broth along with ¼ cup green onion and ¼ cup chopped mushrooms. Boil for 5 minutes
    • While soup is cooking, mix 1.5- 2 tbsp miso with a few tbsp of water, whisk until dissolved.
    • Turn off heat. Add miso mixture to soup and serve!
  • Try a grains bowl with:
    • 1 cup cooked barley, ¾ cup sauteed asparagus and onions and protein of choice
  • Try a salad dressing:
    • mix ¼ cup raw unfiltered apple cider vinegar, ⅓ cup olive oil, 2 tsp honey, 2 tsp dijon mustard, 1 diced clove of garlic, and a sprinkle of salt and pepper

Both prebiotics and probiotics are a hot topic right now due to the emerging research pointing to benefits of their consumption. Incorporating different foods that contain this healthy bacteria on a regular basis could help regulate gastrointestinal function, as well as promote optimal gut health.

If you have additional questions around prebiotics and probiotics or would like direction on selecting a supplement, contact a Health Loft dietitian today or give us a call at (312) 374-5399 or by scheduling an appointment online.  For more tips and fun facts to also check out our FacebookInstagram, and Twitter pages for more articles on nutrition, physical therapy, and exercise!




Submitted by Marissa Gusmao
Edited by Alexander Franz
Reviewed by Morgan Murdock, RD







Cary, et al. “5 Fermented Foods to Boost Your Intake of Probiotics.” Lily Nichols RDN, 2 Oct. 2018,

Davani-Davari, Dorna, et al. “Prebiotics: Definition, Types, Sources, Mechanisms, and Clinical Applications.” Foods (Basel, Switzerland), MDPI, 9 Mar. 2019,

Harvard Health Publishing. “Health Benefits of Taking Probiotics.” Harvard Health,

“Office of Dietary Supplements – Probiotics.” NIH Office of Dietary Supplements, U.S. Department of Health and Human Services,

“Probiotics: What You Need To Know.” National Center for Complementary and Integrative Health, U.S. Department of Health and Human Services,

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