A Guide to Prebiotics and Probiotics for Weight Loss

When people talk about weight loss, they usually focus their attention on macronutrients: protein, fat, and carbohydrates. Popular diets generally involve cutting out or cutting down on one of these (e.g., carbs or fat) while increasing another (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 [source]! Our microbiome, the 100 trillion microbes living in our intestines [source], plays a significant role in our metabolism [source] and may also determine whether we’re overweight, thin, or somewhere in between, although further studies are needed to define this complex relationship [source].

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

You’re probably thinking: What? Fecal transplant?! That’s disgusting! Agreed. But it’s working—not only on mice, but they are also studying its effects on humans.

According to Chris Kresser, 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 supporting the health of your intestinal ecology [source].

Prebiotics for Weight Loss

Prebiotics are dietary fibers necessary for creating an environment in the gut where good bacteria can thrive. This is because the healthy bacterial cultures feed on the prebiotic ingredients that are not digested [source].

Some experts think that prebiotic therapy has more potential in patients because it is difficult for probiotics taken orally to reach the final parts of the colon. You can think of prebiotics as good 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 (specifically green banana)
• Beans and legumes
• Peas
• Potato skins

Probiotics for Weight Loss

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 brain health, immunity, bone density, blood sugar, mood, and even our intuition!

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.

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 survive transit through the human GI tract is called Bifidobacterium lactis (HN019) [source]. This probiotic strain can also increase the populations of other good bacteria in the gut, such as other bifidobacteria and lactobacilli [source].

Another probiotic that is able to safely transit and remain in the gastrointestinal tract is Lactobacillus plantarum [source]. It is found in fermented foods like “live” sauerkraut and fermented olives.

Fermented foods are effective for introducing mixed colonies of living microorganisms to the gut [source]. In addition to sauerkraut and olives, other great fermented foods include:

• kimchi
• kefir
• kombucha
• pickles (with live cultures)
• miso
• tempeh
• natto
• raw cheeses
• plain yogurt

When choosing these foods, it is important to check the label to make sure they contain live and active cultures and have not been pasteurized to kill the microorganisms [source]. 

Fermented foods are excellent for using as a condiment, meaning taken in small amounts to complement the meal. I like to add a tablespoon of kimchi or sauerkraut to my meals, or drink 4 ounces 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 focus specifically on balancing the gut flora. As a 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 will be able to grow in your gut. Then, I use a 4-step protocol to support the intestinal mucus membranes, feed the good bugs with prebiotic fiber, introduce colonizing probiotics to remove undesirable microbes and create microbial diversity in the gut, and maintain proper bacterial balance with fermented foods and probiotic supplements as needed.

This post was medically reviewed by Dr. Amy Shah, a double board-certified M.D. who specializes in helping busy people repair their microbiome and reduce inflammation. Learn more about Hello Glow’s medical reviewers here. As always, this is not personal medical advice, and we recommend that you talk with your doctor.