Weight + Microbiome: Can you poop out more energy?

Microbiome Diet Energy Weight


Your gut microbiome influences your immune system, sex hormone concentration, your mood, and your metabolism. If we were to use your own DNA to predict your body weight it might be accurate about 50% of the time. If we were to use the DNA of your gut microbiome to predict our weight, it would be correct about 90% of the time!


Microbiome or Human Genetics?

In 2006 pioneering researcher Jeffrey Gordon showed that you could change a mouse’s body weight by changing the microbiome living in the gut. Transferring the microbes from an overweight mouse to a lean mouse led the lean mouse to gain weight, even without changing the amount of food the mouse was eating.


In follow up research Gordon’s team took the gut microbes from four sets of twins and transferred them to mice. The twins were identical but, one twin was obese and one twin was lean. 


When the mice received the microbiome of the lean twin they stayed lean. When the mice received the microbiome of the obese twin the mice gained weight, even though they ate the same amount of food [1].


Now if you are thinking that this is just an animal study, let’s show you some research exploring how microbiome changes with diet, and its impact on weight.


Comparing Two Different Diets

A recent study published in Nature set out to answer the question: How do different diets impact energy balance? [2]

The researchers took a group of healthy males and females with stable weight and moved them into a metabolic research facility for part of the study.

People in the study received a Western style diet or a gut microbiome nurturing diet for 22 days. They then had a two-week break and swapped over to the diet they did not undertake in the first intervention.

The Western diet contained simple sugars, emulsifiers, refined grains and processed meats.

The microbiome nurturing diet contained fibre, wholegrains, legumes, more fruits and vegetables and did not contain processed food.

You can see an example day of each diet (taken from the research paper) in the tables below:

Supplementary Table 1: Sample Western Diet Menu [3]


Food Description


Grape juice, canned or bottled, unsweetened, without added ascorbic acid

Kellogg’s Rice Krispies Cereal

Sugar, granulated

Bread, white, commercially prepared, toasted

Margarine, regular, 80% fat, composite, stick, with salt

Milk, reduced fat, fluid, 2% milkfat, with added vitamin A and vitamin D


Salad dressing, mayonnaise, soybean oil, with salt

Lettuce, green leaf, raw

Bread, white, commercially prepared (includes soft breadcrumbs)

Pickles, cucumber, dill or kosher dill

Snacks, corn-based, extruded, puffs or twists, cheese-flavor

Turkey breast, low salt, prepackaged or deli, luncheon meat

Cheese food, pasteurized process, American, without di sodium phosphate


Beef, ground, 90% lean meat / 10% fat, crumbles, cooked, pan-browned

Commercial Traditional Italian Sauce, ready-to-serve

Cheese, parmesan, grated

Spaghetti, cooked, enriched, without added salt

Margarine, regular, 80% fat, composite, stick, with salt

Cauliflower, cooked, boiled, drained, with salt

Margarine, regular, 80% fat, composite, stick, with salt

Cookies, vanilla wafers, higher fat

Lemonade-flavor drink, powder

Water, bottled, generic

Puddings, chocolate, ready-to-eat, fat free

Rolls, dinner, plain, commercially prepared (includes brown-and-serve)

Margarine, regular, 80% fat, composite, stick, with salt

Western Diet Unit Beverage


Supplementary Table 2: Sample Microbiome Enhancer Menu


Food Description


Blueberries, raw

Oats, steel cut, dry, Quaker, 3 minute

Water, bottled, generic

Sugars, granulated

Nuts, almonds

Lemonade with added Hi-Maize Corn Starch


Squash, summer, zucchini, includes skin, cooked, boiled, drained, without salt

Cheese, swiss

Spinach, raw

Tomatoes, red, ripe, raw, year-round average

Oil, olive, salad or cooking

Salad dressing, ranch dressing, commercial, regular

Bread, rye

Lentil Soup with added Hi-Maize Corn Starch

Barley, pearled, cooked

Carrots, baby, raw


Beef, top sirloin, steak, separable lean only, trimmed to 0 fat

Commercial Traditional Italian Sauce, ready-to-serve

Cheese, parmesan, grated

Spaghetti, cooked, enriched, without added salt

Rolls, dinner, plain, commercially prepared

Butter, salted

Strawberries, raw

Peas, green, frozen, cooked, boiled, drained, without salt

Butter, salted

Unit Food Beverage


Weight Loss Dumps

Even though participants in the study were eating the same amount of energy (and same macronutrient percentages) with each diet, the Microbiome diet led to participants ‘losing’ more energy . More energy was pooped out! Yes, that means the poos of the Microbiome diet group contained more energy – 485 kJ to be exact.


To put this into perspective, if you took on board an extra 485 kJ per day, it would only take 76 days to store an extra kilogram of fat. Pooping out an extra 485kJ a day is significant for energy balance!


Prebiotics for Weight Loss

A 90 subject weight loss study demonstrated significant outcomes for a weight loss program that included our key Microbiome Essentials prebiotic compared to a control group that received lifestyle advice only.

Over 8 weeks females in the lifestyle only group lost 5.7 kgs. Females in the prebiotic group lost 10.06 kg. This represented a 76% greater weight loss when taking our key prebiotic in Microbiome Essentials daily.


Microbiome Essentials Weight Loss


Increase Diversity, Decrease Weight

Microbiome diversity is a great predictor of overall health. On the Microbiome diet above [2] diversity increased, fibre degraders were more abundant, and the production of beneficial short chain fatty acids significantly increased. There was also a significant reduction in body weight.

Your gut microbiota contribute to many elements of metabolic health and disruptions in gut bacteria (dysbiosis) can lead to: 

  • a reduction in the secretion of hormones and neurotransmitters that help you feel full and reduce your appetite
  • an increase in intestinal permeability, leading to inflammation and insulin resistance
  • increased triglycerides
  • increased depression which may limit daily movement and impact food choices
  • reduced short chain fatty acid production and absorption
  • extracting more energy from food (leaving less in your poop!)


Want to poop out more energy, increase your microbiome diversity, reduce inflammation and support your wellbeing? It starts in the gut! Incorporating more gut nurturing goodness into your day, increasing your prebiotic fibre intake and ensuring lots of variety in plant-based foods is a recipe for success.


Adding in proven prebiotics may be another way to increase the energy you are pooping out, plus all the other pathways that will be enhanced and contribute to positive shifts in body composition by nurturing your microbiome.


Show your gut some love!



  1. Ridaura, V.K., et al., Gut microbiota from twins discordant for obesity modulate metabolism in mice. Science, 2013. 341(6150): p. 1241214.
  2. Berry, S.E., et al., Human postprandial responses to food and potential for precision nutrition. Nat Med, 2020. 26(6): p. 964-973.
  3. Corbin, K.D., et al., Integrative and quantitative bioenergetics: Design of a study to assess the impact of the gut microbiome on host energy balance. Contemp Clin Trials Commun, 2020. 19: p. 100646.

About the Author

Hi, I'm Dr Cecilia Kitic founder of Fertile Gut. We can't wait to help support you on your journey to improving your gut health! Having spent over 20 years researching in the areas of immunonutrition, physiology, biochemistry and gut health we now get to translate science into practice, sooner. Our gut microbiome provides a foundation for our immune system, metabolism, brain and heart health, and hormone balance. With our scientifically crafted natural formulations you will be creating a Fertile Gut!

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