Prebiotics and Probiotics 101 | Functionize Health & Physical Therapy

Prebiotics and Probiotics 101

By July 17, 2019Nutrition
Prebiotics and Probiotics 101

An Overview of the Bugs in Your Gut, and How You Can Cultivate a Healthy Microbiome

There’s a lot of discussion and evolving research about gut health, the human microbiome, and the pre/probiotics that play a leading role in nourishing a healthy gut lining.  But, the topic of prebiotics and probiotics can be incredibly confusing and overwhelming. What are they? Why do we need them? What foods are good sources of these? Can you get what you need from food alone, or do you need a supplement?

Let me help you break it down, and hopefully you will feel a little more confident about your pre/probiotic game.

Your Gut is a Garden

It may sound a little gross, but the reality is that your body is inhabited by an abundance of microscopic organisms including bacteria, fungi, and viruses, that comprise your “microbiome.” Scientists and researchers liken our gut microbiome to a garden of sorts. Certain foods or supplements we consume help to cultivate this garden. In recent years, extensive research has revealed the vital contribution of prebiotics and probiotics in altering the balance in the gut microbiome in a positive way by increasing the amount of helpful bacteria that can ultimately boost immunity, gastrointestinal function, mood, and overall health.  

What are Probiotics?

Probiotics contain a variety of live bacteria (or cultures) that naturally reside in certain types of food as well as supplements, and contribute to the healthy population of microorganisms in the lining of your intestinal tract.  Even though it’s impossible to notice them, they certainly have a remarkable role in all aspects of health.  

Generally speaking, probiotics are considered to be the “good guys.” They help to change and repopulate your intestinal bacteria in order to achieve an optimal balance of gut flora through food and supplements. 

The most common example of a probiotic food is yogurt. Yogurt typically contains two strains of bacteria (Streptococcus thermophilus and Lactobacilllus bulgarius). Look for the words “live culture” on the label, as not all yogurt is a good source of probiotics. There are many other great food sources of probiotics that are readily available in most grocery stores. 

Food Sources of Probiotics

As I mentioned above, make sure to look for the words ‘live culture’ and avoid varieties that contain an abundance of added sugar.

Kefir is a unique dairy product that is actually higher in probiotics than yogurt, and is also more tolerated than yogurt in lactose intolerant individuals.  It’s made when lactic acid and bacteria are combined with yeast, and then added to any type of milk.  

This trendy beverage consists of fermented black or green tea that’s made from a “SCOBY”, which stands for “Symbiotic Culture of  Bacteria and Yeast”. If you’re a kombucha fan, it’s key to look for unpasteurized varieties, as the pasteurized types actually kill off the good probiotic bacteria, therefore defeating the purpose.  

Fermented or Pickled Vegetables*
sauerkraut, kimchi, ginger and pickled beets or cucumbers
*This is not to be confused with shelf stable pickles or beets that have been prepared with sugar and vinegar and heated at high temps which kills off the bacteria, therefore defeating the purpose.  To be sure, look for varieties in the grocery store that are refrigerated and contain live cultures. Or, make your own using a salt and water brine and some seasonings of choice like garlic, ginger or dill, and cover for 1-3 weeks.  

A probiotic food made from fermented soybeans

Fermented Cheese
Feta, Parmesan, Brie and Cheddar

Sourdough Bread

What about Supplements?

Ongoing research is helping to better determine the role of supplements as an enhancement to the probiotics we get from natural food sources. While supplements sometimes may be warranted for certain situations (such as in the management of Irritable Bowel Syndrome, during flu season or travel as an immune-enhancing support, or after a round of antibiotic therapy which completely wipes out both the good and bad components of your microbiome), there are so many varieties to choose from that it can be hard to determine which might be best for your particular health circumstances.  

There are dozens of species of the same type of bacteria used in supplements, which makes it difficult to know exactly what you’re getting.  Additionally, supplements are not regulated in the way that prescription or over the counter medications are, which adds to the confusion when  determining which supplement would be effective. Working with a knowledgeable physician or Registered Dietitian can help determine if a supplement is necessary, and can also point you in the right direction to a reputable brand and product.

What are Prebiotics?

Prebiotics are the indigestible fibers in food that provide fuel and act as a fertilizer to promote the growth of the good bacteria in our gut. Simply stated, they’re the food that the probiotics need in order to re-populate. Since they can’t be broken down by human enzymes, they eventually become fermented by the bacteria in our gut lining when consumed. 

Prebiotics are mainly found in fruits and vegetables, especially those that contain an abundance of fibers and resistant starch.  

Food Sources of Prebiotics

Cruciferous veggies
Flax seeds

Combining prebiotic rich foods which promote the “good” bacteria with probiotic foods creates a synergistic effect in achieving and maintaining a healthy gut microbiome. Here are just a few ideas of what this might look like using food.

  • Yogurt topped with banana and berries and a sprinkle of flax meal
  • Stir-fried asparagus with ginger and tempeh
  • Sourdough toast topped with yogurt and berries
  • A protein smoothie using a base of kefir with berries and flax
  • Kale salad topped with feta, olives, diced red onions and tomatoes with an olive oil/red wine vinegar blend
  • Roasted Brussels / Broccoli and Cauliflower topped with shredded parmesan cheese

The bottom line:  Prebiotics and Probiotics partner together to support digestion, immunity, mental health, and even play a role in weight control and healthy skin. While supplements are widely available, utilizing natural food sources is the ultimate first line of defense and is also the most practical/cost effective. Just one more reason to eat your fruits and veggies! 

I hope this quick dive into the world of pre/probiotics helped clarify some ways to naturally boost your microbiome! If you have questions about your personal need for supplements or would like to dive deeper, feel free to contact me by email, phone, or through my website.  Thanks for reading!

Allyson Balzuweit, MPH, RDN/LD
Instagram: @allysonbalzuweit


Allyson Balzuweit

Author Allyson Balzuweit

Allyson Balzuweit, MPH, RDN/LD Allyson has 20 years of experience as a Registered Dietitian, working in a variety of settings providing nutrition counseling and education to individuals and groups with a multitude of nutrition needs. She enjoys helping others embrace a healthy and realistic approach to eating through a positive and solution based approach. Allyson received a BS in Nutritional Sciences from the University of Connecticut in 1996. After completing her dietetic internship at Massachusetts General Hospital in Boston, she relocated to the Washington DC area, where she began working as a clinical dietitian, and eventually transitioned to outpatient counseling for several years. She is certified in Adult, Child and Adolescent weight management. Allyson has Masters in Public Health from The George Washington University, and became a consultant for a non-profit organization that was committed to providing access to high quality health care to all individuals. After moving to Atlanta in 2005, Allyson has worked with private clients with a variety of nutrition related health issues, consulted for local fitness clubs, and has spent the last 5 years in public health, specifically focusing on patients with HIV and compromised immune status. Allyson lives in Smyrna, GA with her husband, 3 children and her newly adopted black lab. She enjoys running, cooking, and family time.

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