illustration of a stomach made of bacteria
Ann Louise Gittleman, PhD, CNS

Ann Louise Gittleman, PhD, CNS

Award-winning nutritionist and New York Times bestselling author.

November 30, 2020

Skinny Gut – How Gut Bacteria is Tied to Weight Loss

It’s true – there are “hidden” factors, beyond diet, exercise, and your own willpower, that are making you fat. Research now confirms that weight loss is also about an array of newly uncovered concerns that are contributing to the obesity epidemic.

What’s Weighing You Down?

When you address and correct seemingly unrelated factors such as your body’s microbes, you can drop those pounds for good. You’ll restore your body’s natural ability to regulate metabolism and detoxify. Controlling what is really weighing you down might just change your total outlook as well as your outfit.

Let’s take a more careful look at the new scientific research that has enhanced many of my weight loss protocols.

Gut Bacteria

For years, beneficial bacteria have been known to fight yeast, combat disease-causing bacteria, help clean out parasites, and break down toxins in the body. Conversely, a lack of the beneficial bacteria has been connected to many health problems, including ulcers, irritable bowel syndrome (IBS), chronic fatigue, eczema and psoriasis, asthma, and more. And now there is a connection to weight.

Groundbreaking Study

In a groundbreaking landmark study published in Nature (December 2006), researchers found that without the right amounts of friendly bacteria, animals got “twice as fat” and utilized more calories from the same amount of food than those with the more normal bacteria ratio.

Taking supplemental probiotics (beneficial bacteria or friendly flora) may be the real deal when it comes to losing weight. I developed Flora-Key in response to game changing findings suggesting a strong connection between obesity and the levels of certain types of bacteria in the gut.

Probiotics Important Role

Probiotic means “for life”. Probiotics play an important role in the digestion of foods and help to produce B vitamins, vitamin K, as well as digesting fiber – the short-chain fatty acids upon which your colon desperately relies. In the right balance of power, a ratio of 85 to 15 in favor of the “good guy” bacteria, probiotics are so vital to good health that they are considered an “organ” by many experts. In reality, these friendly flora also make up most of your immune system, because 60 percent of your immune system’s receptor cells are in your large intestine and another 15 percent reside in the small intestine.


This groundbreaking research, conducted at Washington University’s Center of Genome Sciences, initiated a whole science called “infectobesity” that looks at obesity from the microbial and viral standpoint. Simply put – viruses and bacteria may impact the absorption of food and influence gut hormones that regulate appetite and metabolic rate.

For years, probiotics have been an integral part of my dietary protocols in such books as The Fast Track Detox Diet, The Gut Flush Plan, Fat Flush, and Radical Metabolism. For basic weight loss and cleansing purposes, I am recommending Flora-Key, a powdered probiotic supplement that I have been using in private practice for over fifteen years. It can do double duty as an immune booster and natural sweetener because we are cutting out sugar, sugar alcohols, and artificial sweeteners.

Sweet Benefits of Flora-Key

Flora-Key contains a basic combination of lactobacillus, bificobacterium, and frucooligosaccharides (FOS) from complex sugars that function as a prebiotic. A prebiotic is a food that feeds the beneficial bacteria while discouraging pathogens. FOS is a naturally occurring sweetener in fruits and some vegetables. It tastes sweet but the molecules are too big to be digested by the body as sugar, so it doesn’t affect blood sugar levels. It also can’t be utilized by Candida and other yeasts.

The Best News

The best news about FOS, though, is that it provides a benefit that none of the other sweeteners do: It nourishes and promotes the growth of friendly intestinal bacteria such as bifidobacteria in your large intestine without feeding pathogenic bacteria.

This makes it a potentially good-for-you sweetener for people struggling with weight, yeast infections, and other gastrointestinal (GI) disorders. With Flora-Key, you get the best of both worlds: a probiotic fed by a prebiotic. You can take two to three teaspoons per day. For a special treat with all the Flora-Key benefits, try my recipe taken from my original Fat Flush Plan:

Fruity Fruit Sorbet

Makes 1 serving.

  • ½ cup strawberries, halved
  • ½ cup raspberries
  • 1 teaspoon fresh lemon juice (optional)
  • ½ teaspoon Flora-Key

Place all ingredients in a food processor or blender and puree until smooth.

Freeze until firm (about 3-4 hours only). Enjoy!

Be sure to check my other gut-related blogs and podcast here:

Related Articles and Podcasts

Ann Louise Gittleman, PhD, CNS, is an award-winning New York Times bestselling author of more than thirty books including The Fat Flush Plan series and her latest book, Radical Metabolism. She’s been rewriting the rules of nutrition for more than 40 years and is internationally recognized as a pioneer in the field of diet, detox and women’s health issues. 

For a FREE daily dose of tips and strategies for maintaining healthy weight, conquering insomnia, and much more…check out my Radical Health Tips.

I’d like to meet and greet you on my Facebook groups, so won’t you check us out at the Radical Metabolism RevolutionFat Flush Nation, or my Inner Circle!


  1. Laura Ann

    It’s so interesting that having the right bacteria balance relates to weight loss. I’m going to try the Flora-Key.

  2. Tish A.

    I really appreciate links to other information your given out. I really need help in this area.

    • Ruth

      That sorbet recipe sounds delicious. I didn’t know you could do that with probiotics. I’m definitely going to make it. I have some Flora-Key on hand.

  3. Tory

    I’ll try anything to get my weight loss going. Maybe this will be a key for me.



  1. Skinny Gut – How Gut Bacteria is Tied to Weight Loss – DietMarkets - […] Original Article […]

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