Co-written by Dr. Mikaila Brown, ND & Bella DeBartolo, soon to be Certified Nutritional Practitioner (CNP)

Probiotics are a trending topic in the health and wellness space, but have you heard of prebiotics?

As you’ll learn today, prebiotics and probiotics work synergistically to build and maintain a well-functioning and balanced gut microbiome. Understanding the importance of both probiotics and prebiotics is not only key for a healthy gut, but is also important for disease prevention and whole body health. Today, we are going to dive into the difference between the two, their synergistic role on gut health, food sources of both and why they can sometimes worsen gut symptoms.

The Gut Microbiome

Before diving into the topic of probiotics and prebiotics, let’s start with a basic understanding of the gut microbiome.

• Our gut microbiome is an ecosystem made up of trillions of microbes including bacteria, yeasts, parasites, viruses and archaea, all of which are involved in digestive function, immunity, cognition, skin health, metabolism, hormone balance, and more.
• “Dysbiosis” refers to the loss of harmony and balance within the gut microbiome, leading to the overgrowth of inflammatory “bad” bugs and intestinal hyper-permeability, commonly referred to as “leaky gut.”
• Dysbiosis is one of the primary root causes of many common digestive health concerns, including IBS, chronic constipation, food intolerances, chronic bloating/abdominal distention, GERD/reflux, diarrhea, excess gas, abdominal pain/cramping and belching.
• The impact of dysbiosis goes beyond the health of the gut. Other signs of gut dysbiosis include acne, eczema, weight gain, insulin resistance, hormone imbalance, anxiety and depression, brain fog, fatigue, joint pain and nasal congestion.

While there is no clear definition of a healthy gut microbiome (it is likely as unique as our own fingerprint), some key features of a healthy microbiome include:

• a high level of diversity,
• a favourable amount of bacteria that make beneficial compounds known as short chain fatty acids (SCFAs),
• resistance (the ability to resist the invasion of pathogens and overgrowth of “bad” bacteria)
• resilience (the ability to “bounce back” after disturbances such as food poisoning or antibiotic use),
• tolerance (the ability to tolerate non-harmful substances, such as food or self, without abnormal immune responses)

Now let’s dive into the role of probiotics and prebiotics on our gut microbiome!

Probiotics

Probiotics are the “healthy” microbes found in our gut, in fermented foods and in specific supplements. When consumed, these probiotics are intended to colonize in the colon to enhance the health of the microbiome and benefit the health of the host (us, the humans!) . There is a growing body of research diving into the potential role of specific probiotic strains in the treatment and prevention of various diseases and health concerns.

There are many different strains of probiotics out there, but a few of the most popular include:

• Saccharomyces boullardi: typically used for various types of diarrhea 
• Bifidobacterium lactis: typically used for constipation 
• Lactobacillus acidophilus: useful in treating/ managing IBS 
• Lactobacillus rhamnosus: possibly useful in treating acne 

It is important to note that in order for a probiotic to colonize in the colon and exert their positive health effects, they require the proper living conditions. Some important factors include the proper acidity within the colon and an adequate food source. If the environment within the gut is not compatible for survival and a food source is not available, the probiotics are not going to make a long-lasting impact. For this reason, probiotics are not likely to correct dysbiosis or reverse disease in the context of a poorly functioning gut or an unhealthy diet. The underlying causes of the dysbiosis and drivers of disease must also be addressed for probiotics to have a meaningful impact.

Prebiotics

Prebiotics refer to the “food” for the healthy gut microbes. They promote the growth and maintenance of healthy microbes by providing fuel for their survival. During the digestive process, the probiotics (healthy gut microbes) metabolize and ferment the prebiotics, resulting in the production of metabolites, such as short-chain fatty acids (SCFAs). SCFAs have numerous beneficial effects on gut barrier function, support the prevention and repair of “leaky gut,” help combat the invasion and overgrowth of inflammatory bugs, support proper nutrient metabolism/absorption, and so much more.

Without prebiotics, probiotics cannot exert their positive effects!

Prebiotics (the food) are used by Probiotics (the microbes) to make health promoting compounds called Postbiotics (SCFAs being the most common).

Food Sources of Probiotics

Probiotics are found in any fermented foods, including:

• Grass-fed yogurt
• Grass-fed kefir
• Coconut yogurt 
• Kimchi
• Sauerkraut
• Tempeh
• Miso 
• Kombucha 
• Water kefir

Food Sources of Prebiotics

Prebiotics are naturally found in all plant foods, so a diet rich in fruits, vegetables, beans, legumes, nuts, seeds, and whole grains will naturally support a healthy microbiome. That being said, foods rich in fermentable carbohydrates, polyphenols, omega-3s, and resistance starch exert a particularly powerful prebiotic effect on the gut. Some of my favourites include:

• Onions*
• Garlic*
• Barley *
• Green bananas
• Oat
• Beans/ Legumes*
• Cooked and cooled potatoes/sweet potatoes
• Cocao powder
• Flaxseeds
• Blueberries
• Green tea
• Apples*
• Chicory root / Inulin*
• Pomegranate juice

Why do probiotics / prebiotic rich foods make my symptoms worse?

If adding probiotic or prebiotic rich foods seem to wreak havoc on your digestion, there are a few things to consider:

1. Constipation: Adding probiotics and prebiotics to a backed up system is like adding fuel to the fire. If you are not completely emptying on a daily basis, adding probiotics and prebiotics will cause worsened gas, bloating, and constipation. In this case, it is important that the constipation is addressed before adding in probiotics and prebiotic rich foods.
2. Overgrowth dysbiosis: In the context of bacterial overgrowth, fermentable soluble fibres (the foods above with an asterisks*) are likely to cause excess gas production, bloating, pain and altered bowel habits, due to over-fermentation. This overgrowth may need to be directly treated with antimicrobial herbs or antibiotics before incorporating probiotics and prebiotics.
3. Low fiber tolerance: If you generally eat a low fiber diet and suddenly increase your prebiotic (fiber) intake, you may experience an increase in gas and bloating because your microbiome is not currently adapted to handle large amounts of fiber. Fortunately, the gut microbiome is highly adaptable. Slowly increase your fiber intake by ~5-10g every 1-2 weeks in order to build up your tolerance to higher amounts of fiber.

Ready to reclaim your gut health?

As a gut-focused naturopathic doctor, I specialize in treating the various root causes of chronic gut issues. By digging deeper and uncovering the underlying factors contributing to your discomfort, you’ll no longer need to avoid your favourite foods to manage symptoms or wonder why you’re always bloated. With a personalized, step-by-step plan tailored to your needs, you’ll have all the tools you need to restore balance in your body and optimize your gut health.