Pre- and Probiotics for Weight Loss

Typically, when people talk about weight loss, they focus their attention on macronutrients: protein, fat and carbohydrates. Popular diets generally involve cutting out or cutting down on one of these (i.e. carbs or fat) while increasing another (i.e. protein). Truth is, when it comes to losing weight, there is a lot more going on with respect to the foods we eat than simply macronutrients. What these fad diets are missing is the critical importance of the microbiome - a topic of much emerging research! Our microbiome, the 100 trillion microbes living in our intestines, plays a massive role in determining whether we're fat or skinny or somewhere in between. 

How cool is this fascinating research on mice: If you take the fecal matter (with the microbiota) from a skinny mouse and transplant it into a fat mouse, the fat mouse loses weight. By the same token, fecal microbiota from a fat mouse transplanted into a skinny mouse will result in the skinny mouse gaining weight. 

You're probably thinking What? Fecal transplant?! That's disgusting! Agreed. But it's working....not only on mice, but also on humans.

In a recent study on humans, a fecal transplant was performed by taking the fecal microbiota from a healthy, lean individual and transplanting it into a person with weight, heart, circulatory and blood sugar issues, and the researchers found significant improvements in the health of the recipient. These findings are just the tip of the iceberg. 

According to Chris Kesser, licensed acupuncturist and practitioner of integrative medicine, a healthy gut is the hidden key to weight loss. “The composition of the organisms living in your gut determines – to some extent, at least – how your body stores the food you eat, how easy (or hard) it is for you to lose weight, and how well your metabolism functions.”

So the key to weight loss is creating an environment in your gut that allows the natural proliferation of healthy and diverse strains of good microbes that will naturally keep the bad ones in check. Both prebiotics and probiotics are critical to support the health of your intestinal ecology.


Prebiotics are necessary for creating an environment in the gut where good bacteria can thrive because the probiotic cultures feed on the ingredients of the prebiotic. You can think of prebiotics as food for probiotics. Below are some good sources of prebiotic fiber: 

  • Jicama
  • Asparagus
  • Jerusalem artichoke
  • Chicory root
  • Dandelion greens
  • Allium vegetables such as garlic, onion, leeks, chives, and scallions
  • Avocado
  • Cabbage
  • Banana
  • Beans and legumes
  • Peas
  • Potato skins


While the benefits of probiotics were once thought to be restricted to gut and digestive health, new research on the gut-brain axis is connecting our microbiome to the health of the brain, immunity, bone density, blood sugar, mood and even our intuition! 

There are a few things you should know about probiotics: 

  1. Only a few have the ability to make it through the stomach acid, the liver's bile secretions and the pancreatic enzymes without being destroyed.
  2. There is a distinction between transient and colonizing probiotics.
  3. Most probiotic supplements on the market today are transient probiotics, meaning they transit through the gut but do not make a permanent or lasting change to the microbiome. They can make you feel better, for sure, but once you stop taking them, the microbiome generally returns to its original state before probiotic use. 
  4. Colonizing probiotics actually adhere to the gut wall, become permanent residents, and build microbial diversity. 

One microbe that has been shown to adhere to the gut wall and able to survive transit through the human GI tract is called Bifidobacterium lactis (HN019). This probiotic strain can also increase the populations of other good bacteria in the gut such as bifidobacteria and lactobacilli. 

Another probiotic that is able to safely transit the gastrointestinal tract and adhere to the gut wall is Lactobacillus plantarum. It is found commonly in fermented foods like sauerkraut and fermented olives. 

In addition to sauerkraut and olives, other great fermented foods include: 

  • kimchi - recipe for making your own here!
  • kefir
  • kombucha 
  • pickles
  • miso
  • tempeh
  • natto
  • raw cheese 
  • yogurt 

Fermented foods are excellent for using as a condiment, meaning taken in small amounts. I like to add a tablespoon of kimchi or sauerkraut to my meals, or drink 4 oz of water kefir or kombucha (not the whole bottle!), or sprinkle a little raw cheese on a meal. 

With any client looking to lose weight, I always analyze the state of their gut, and specifically hone in on balancing the gut flora. As physician and author of The Microbiome Diet, Dr Raphael Kellman,  says, "It's less about eating a certain percentage of carbohydrates, protein and fat than about correcting the overgrowth of unhealthy bacteria, which is making you crave the wrong foods, triggering inflammation." 

Working with clients to create a healthy microbiome, we first work on the food piece because what you eat dictates the kind of bacteria that grow in your gut. Then, I use a 4-step protocol to support the intestinal mucus membranes and feed the good bugs with prebiotic fiber, introduce colonizing probiotics to remove undesirable microbes, boost colonizing microbes to create microbial diversity in the gut, and maintain proper bacterial balance with fermented foods and probiotic supplements as needed. 

Steph x