Like Gifts? Get Your Free Thyroid Mastery Ebook!

Why Yes!

Ready to Reclaim Your Health?

Let’s meet up – in your inbox.

Subscribe Now

How Artificial Sweeteners, Sugar, and Sugar Substitutes Impact Your Gut Microbiome

May 30, 2021

How Artificial Sweeteners, Sugar, and Sugar Substitutes Impact Your Gut Microbiome

The impact of artificial sweeteners, sugar, and sugar alcohols on the gut microbiome is a common conundrum. Many people reach to artificial sweeteners and sugar alcohols to reduce their caloric intake for weight loss, but does replacing sugar with a substitute cause further health havoc, especially in the gut? That is the question! Let’s dive into what impacts your gut microbiome & what you can do to optimize it with your choice of sweeteners as well.

The Difference Between Sugar and Sugar Substitutes 

Sugar and sugar substitutes may share similar tastes (sometimes…), but they have different effects on your body in relation to their impact on digestion, influences on the gut microbiome, and contribution to inflammation.

The Types of Sugar

“Sugar” is a simple carbohydrate that can be found naturally in your food, such as in fruits, carbohydrate rich foods, dairy products, or vegetables, or it can be man made or extracted from a natural product, as in the case of table sugar or high fructose corn syrup. When we think of sugar as in the case of sucrose, this is man-made of glucose and fructose molecules. Technically, all foods that we eat break down into “sugars”, aka monosaccharides. However, in the case of this article and talking about “sugar’s” impact on the gut, we are are referring to the man-made sucrose.

Natural sugar substitutes come from food sources, much like sugar. Examples include: 

  • Honey
  • Maple syrup
  • Stevia
  • Sugar alcohols (Ex. Xylitol or Erythritol)

Artificial sweeteners are chemical food additives that are added to food to replicate the taste of sugar. The main purpose of these sugar alternatives is to mimic the sweet taste without providing the calories, as their calories are unable to be broken down and absorbed by the body.

The most common artificial sugar substitutes are:

  • Sucralose
  • Saccharin
  • Aspartame
  • Acesulfame-Potassium
  • Neotame

What is the Gut Microbiome and How it Impacts Your Health 

Your intestines contain intricate ecosystems of trillions of microorganisms that make up your gut microbiome. Your microbiome is incredibly complex, and is composed of beneficial bacteria, fungi, yeast, and more, that play many roles to keep your body healthy.

Your gut microbiome is as unique as your fingerprint! The truth is – we don’t even know what a “healthy microbiome” truly looks like yet. We also don’t fully know how each bacteria strain can affect our body’s metabolism, mood, disease risk, nervous system, immune system, etc. We don’t even know all the microbes that reside in our gut! Trying to understand our gut microbiome is like trying to understand all the stars and planets in our galaxy. New studies are being conducted every day, so stay tuned.

Gut Microbiome - an overview | ScienceDirect Topics

What we do know is that the gut microbiome impacts your:

  • Digestive system – Microbiota in the gut maintain a healthy digestion, preventing stomach irritation, gas, and bloating. Your large intestine hosts a beautiful ecosystem or “microbiome” that help to ward off pathogens and synthesize micronutrients such as vitamin K and B-vitamins. These microbes also help to convert consumed fiber into short-chain fatty acids, which are then used for the regulation of your metabolism and the maintenance of your gut lining.You are not what you eat- you are what you digest and absorb- and your microbiome plays a big role in this!
  • Immune system – Microorganisms in your gut keep in constant contact with your immune system. In fact- 70% of your immune system resides in your gut! Think of your gut lining like a door. You want the “good guys” to come in, & the “bad guys” to stay out!⁣ Well- with increased intestinal permeability or what some call “leaky gut”– your door has a crack. The tight junctions within your gut become loose- allowing undigested food particles, toxins, & microbes to go from your gut to your bloodstream⁣. Cue inflammation, digestive distress, & food intolerances!!⁣
  • Endocrine system – Bacteria, fungi, and yeast in the gut produce metabolites, peptides, and short-chain fatty-acids that are contribute to endocrine function, including your metabolism. SCFAs also play a critical role in mucus production, inflammation, bile acid metabolism, and cholesterol metabolism. They can even affect your brain by inducing the secretion of the hormones GLP-1 (glucagon-like peptide 1), PYY (peptide YY), GABA (y-aminobu‐ tyric acid), and serotonin. Therefore, SCFAs play an integral role in emotion, satiety, cognition, mood, and brain health. This heavily influences your mood, behavior, cravings, and meal satiety.
  • Brain – The gut microbiome is known as the “second brain” and is involved sending crucial messages along your central nervous system (CNS) via the vagus nerve. This interaction is called the gut-brain-axis. Important truth- The gut is not like Vegas. What happens in the gut doesn’t stay in the gut. Have you ever felt so anxious that you were sick to your stomach? That is your gut and brain communicating. Inflammation in your gut can impact your mood and behavior. If your stressed, this can inhibit and slow digestion, causing gas and bloating, as well as increase your risk of intestinal permeability. Having a healthy gut brain connection, stimulating your vagus nerve, and keeping stress in check are essentials to a healthy microbiome.
  • Body clock – An essential part of the gut-brain connection is maintaining your ‘body clock,’  or circadian rhythm. Dysregulation in your circadian rhythyms can alter your digestion and gut microbiota, as well as your hormonal and metabolic health. Skipping meals can cause blood sugar and cortisol dysregulation, which can create disruptions to the health of your gut and microbiome.
Vitamins for the Gut Microbiome: Trends in Molecular Medicine

Because of the many functions the gut microbiome plays in your body, it’s important to keep it healthy and happy! The key to keeping your microbiome rich and strong is maintaining a healthy, anti-inflammatory diet and consuming a variety of plants in your diet! Keep reading for more….

The Best Diet For A Healthy Microbiome

What you eat has a direct influence on the health your gut microbiome.

The microorganisms within your intestinal tracts are highly sensitive to what you eat. The result can be either positive or negative, depending on the foods you are most often consuming. How? We look at whether a food increases or decreases inflammation, how a food contributes micronutrients to the diet, and how the food selectively feeds (or doesn’t feed) your microbiome!

A healthy, balanced diet is an essential component of a rich, diversified microbiome. The “best diet” for your microbiome is one that feeds your benefical gut bugs. Foods that provide gut bacteria, fungi, yeast, etc. the opportunity to flourish contain ample micronutrients, phytochemicals, and fiber. These include:

  • High-fiber foods – Focus on prebiotic rich foods such as asparagus, chicory root, onions, jerusalem artichoke, wheat, jicama, banana, barley, peas, leeks, and beans. Other natural prebiotic foods include egg plant, chia seeds, sweet pota‐ toes, yacon root, barley, kefir, fruit, green tea, garlic, onions, and plantains. Prebiotics can be defined as “a substrate that is selectively utilized by the host microorganisms conferring a health benefit.” In easy terms, they help you or your gut upon ingestion in some way .
  • Probiotic foods – Focus on consuming live strains contained in yogurt, kefir, tempeh, and kimchi. Probiotics can be defined as “live microorganisms which, when administered in adequate amounts, confer a health benefit to the host.” Probiotics can be incorporated into supplements through capsules, powders, and tablets, as well as added into food, such as yogurts, milks, and even breakfast cereals.

Though normally thought of as a naturally occurring probiotic, fermented foods including kefir, sauerkraut, and yogurt are actually not considered probiotics themselves. Instead, they are consid‐ ered to contain “live and active cultures.” 

  • Colorful fruits and vegetables – Bright and dark colored plants contain higher amounts of antioxidant micronutrients and phytonutrients, including swiss chard, dragon fruit, and blueberries. Polyphenols will help support a healthy gut lining and assist in combatting inflammation, as well as help your gut to produce SCFA’s.
  • High-omega fat foods – Incorporate health fats such as wild caught salmon, nuts, seeds, avocadoes and olive oil to help reduce gut inflammation and support healthy hormones. Adequate fat is also necessary to “coat” the gut lining. Lack of dietary fat and lead to constipation!
  • Antioxidant herbs and spices – Spice up your diet with herbs to help reduce oxidative damage and inflammation. My favorites include ginger, turmeric, astragalus, celery root, parsley, and cinnamon.
  • Additional lifestyle strategies to support your gut include: maintaining adequate sleep, staying physically active, prioritizing self care and stress reduction, minimizing endocrine disrupting chemicals, drinking adequate water, and avoiding antibiotics unless necessary.
Prebiotics vs. Probiotics - What's the Difference?

The Worst Foods For Your Gut

When you consume a diet of primarily ‘junk foods’ with high processed vegetable oils, low-fiber, and high in added sugars, you both increase gut and body inflammation, contribute to dysbiosis, and starve your microbiome of it’s fuel to thrive!

Foods that negatively affect the microbiome:

  • Fatty meats
  • Processed and deli meats
  • Fried foods
  • Processed vegetable oils
  • Excessive alcohol 
  • Too many artificial sweeteners, gums, and food additives and preservatives
Poor Gut Health Causes & Effects | Sprout Into Wellness | Gut health,  Health, Functional medicine doctors

How Sugar and Sugar Substitutes Impact the Gut Microbiome

Sugar and sugar substitutes are no exception on their impact on your gut microbiome. Of course, the overall impact relies upon the different type, the additional food ingredients or components, as well as overall quality of the diet.

Gut Check: Sugars and the Gut Microbiome – Food Insight


Excessive amounts of refined sugars feeds pro-inflammatory bacteria in the gut and allows them to flourish. Not only does this stimulate chronic inflammation, but it also reduces colonies of anti-inflammatory bacteria, weakens the intestinal barrier, and increases gut acidity. In the case of SIBO or Candida, these bacteria will flourish and thrive, contributing to further dysbiosis and crippling symptoms.

Natural Sugars and Sweeteners

Natural sweeteners are also simple carbohydrates, but they have not been refined like table sugar. Hence, they maintain their nutritional value, including micronutrients, antioxidants, and phytochemicals. 

Some of the most common natural sugars include: 

  • Honey
  • Maple syrup
  • Agave nectar

Though they may seem healthier, they work the same way in the body as refined sugars do, being converted into a simple carbohydrate molecule that is easily absorbed by the body. This doesn’t make them bad- however just like sucrose and table sugar, this can fuel pathogenic microbes if SIBO and Candida are present, as well as add additional calories into the diet. Just because it is a “natural” sugar doesn’t mean it is a calorie free or healthier sugar. These sugar substitutes, because they provide additional nutrition compounds, are a better alternative to straight sugar. They also have other benefits, for example, honey has anti-inflammatory purposes, and manuka honey can be used for the erradication of H pylori.

But just like added refined sugars, excessive amounts of natural sugars and sweeteners can wreak havoc in your gut by stimulating chronic inflammation of the intestinal lining and causing dysbiosis in the gut. What matters is that you focus on reducing your intake of added sugars, and promote the intake of complex, fiber and prebiotic rich carbohydrates! I suggest keeping added sugars under 10g per serving, and 20g per day. Don’t worry about fruit sugars- eat those to your heart’s content! My favorite calorie free natural sugar substitutes include stevia, monk fruit, and then low calorie allulose.

Sugar Alcohols 

Sugar alcohols are also another natural sugar substitute that can be used on their own or in foods/drink products. They are not actually an alcohol (not containing ethanol), but in fact are another type of carbohydrate. They act almost like fiber, as they can’t be fully digested in the gut, and in term, have little to no caloric value. See more here!

The most common types of sugar alcohols are: 

  • Xylitol
  • Erythritol
  • Sorbitol
  • Malitol

Each sugar alcohol has it’s own caloric value and digestability.

Sugar Alcohols and Diabetes: What You Need to Know – Diabetes Daily

There are mixed reviews of sugar alcohols and their effect of the gut microbiome because they are largely indigestible. A majority of these sweeteners cause several problems in the gut, including stomach upset, bloating, gas, and for some- diarrhea. However, their effects seem to be both person by person dependent and dose dependent. For example, malitol and sorbitol tend to produce more negative side effects than erythritol.

Text link to paper: https://pubmed.ncbi.nlm.nih.gov/32326137/#&gid=article-figures&pid=figure-1-uid-0

Artificial Sweeteners


Sucralose is a synthetic derivative to sucrose (table sugar) with zero calorie content. This artificial sugar substitute is most associated with the sweetener, Splenda, which is used to replace sugar in cooking and baking.

Sucralose is generally considered safe for use by the FDA, but research as suggested that long-term consumption of this sugar substitute could have detrimental effects on your health and a connection to potential cancer risk. This is dose dependent.

In terms of the gut microbiome, sucralose has been connected to negative outcomes of beneficial gut bacteria. Studieshave found that consumption of this sweetener for over 12 weeks decreased colonies of anaerobic gut bacteria by 47-80%. This includes strains of bifidobacteria and lactic acid bacteria, essential for maintaining intestinal structure and communication with the immune system. It seems that this sweetener may be the most profound for its effects on the gut. Little is known to what dosage this occurs. Additional studies also provide evidence that sucralose may not indeed impact the gut microbiome, while others show a correlation to colitis. The final verdict is up in the air.


Saccharin is another non-nutritive sweetener and contains no calories or carbs. It is also one of the oldest sugar substitute options available used to sweeten drinks and food for over 100 years.

Most common names that saccharin is sold under are:

  • Sweet n’ Low
  • Sweet Twin
  • Necta Sweet

Like sucralose, authorities in health and food regulation consider saccharin safe when consumed in moderation with possible links to health risks, like cancer development. ‘Safe’ consumption of saccharin is considered 2.3 mg per pound of body weight by the FDA. 

This sugar substitute has been connected to gut disruption. Specifically, colonies of anaerobic gut bacteria. By reducing the number of anaerobic bacteria located within the gut, saccharin has been associated with interfering with a healthy microbiome. However, studies proving this have been done largely in rats and high doses that go beyond generic human intake. Some studies have strictly used mice derived fecal transplants to assess saccharin and artificial sweetener gut impacts. This indeed has its own flaws, as correlation can not equal causation and confounding factors are at play.


Aspartame is one of the most widely used sugar substitutes on the market, but also one of the most prolific. It is sold under the names Equal and NutraSweet for consumers to purchase and is especially common in “diet” foods in attempt to reduce calories while providing the same sweetness.

Aspartame is made from aspartic acid and phenylalanine, which are natural amino acids. As it is processed by the body, it is broken down in to methanol, similar to the breakdown of fruit, fruit juice, fermented beverages in the body. 

Because aspartame is rapidly hydrolyzed in the small intestine, it makes it difficult to determine exactly what the effect aspartame has on gut bacteria. Some associations have been made to aspartame and headaches, however more evidence is needed to make a causation here. In relation to the microbiome, little has been found on aspartame’s effect on the microbiota. There is some evidence to indicate it has neglible impact.


Acesulfame-potassium, also known as acesulfame-K or Ace-K, is an artificial sweetener that is 200 times sweeter than table sugar. 

It is known for being calorie-free and commonly being blended with other artificial sweeteners due to its bitter aftertaste. 

Products that commonly contain Ace-K are: 

  • Soft drinks
  • Mixed drinks and shakes
  • Frozen desserts
  • Baked goods
  • Candy and gum

The sweetener is most associated with reducing functional capacity of the gut microbiota by reducing good bacterial colonies in the gut (like Lactobacillus and Clostridium) and increased adverse bacteria colonies. However, as Ace-K is eliminated 99% in the urine and 1% in the stool, it is highly unlikely that it reaches the gut to impact the gut microbiome. Rat studies show this to be dose dependent with impacts. Some show that in higher quantities, higher levels of Firmicutes (correlated to be higher in obese individuals) and lower levels of Akkermansia are found, indicating a negative impact on the gut.

Characteristics and properties of the most used artificial sweeteners. |  Download Scientific Diagram
Photo source: https://www.researchgate.net/figure/Characteristics-and-properties-of-the-most-used-artificial-sweeteners_tbl2_333180075

Should You be Consuming Sugar and Sugar Substitutes?

Research shows that a high intake of added sugars is detrimental to your overall health, including your gut microbiome. The replacement of added sugars with artificial sweeteners and/or sugar alcohols may help, or hinder your digestion in regards to person to person symptoms, however based on the current literature, artificial sweeteners themselves seem to have neglible impact on the gut microbiome in low doses. The current testing done on rats in high doses showing abnormal findings can not be used to correlate with humans. In addition, many studies include maltodextrin to feed or provide the artificial sweetener, which has been found in itself to potentially negatively impact the microbiome. Take these studies with a grain of salt until more human trials are done.

For overall health, consume most of your sugars from natural sources that provide additional nutritional value. Aim for complex carbohydrates, fruits, vegetables, and choose your sweeteners in low doses based on perference. My favorites include stevia and monk fruit. 

Ways to Improve the Health of Your Gut Microbiome

If you are concerned about the health of your gut or are experiencing the effects of an unhealthy gut microbiome, it’s important to look at changing your lifestyle & diet!

Luckily, there are a variety of changes you can make in your day-to-day life that can positively impact your gut microbiome. Also, many of these are holistic lifestyle changes, which can improve not just your gut, but your overall health and well-being.

Simple, yet important, steps to improve the health of your gut microbiome include:

  • Adopt a healthy, balanced diet – Consume plenty of food associated with promoting a healthy microbiome including prebiotic and probiotic foods, fiber and prebiotic rich foods, colorful produce, cruciferous vegetables, foods containing ample omega fatty acids, and antioxidant herbs and spices. Try to reduce your intake of processed foods filled with preservatives, gums, and fillers that can cause gut irritation and potential dysbiosis.
  • Engage in regular physical activity – Exercising (but not too much) is a part of maintaining a healthy gut! Not only does this help aid in motility to prevent bloating and gas, but also helps to keep a healthy microbiota composition. I suggest utilizing both resistance and aerobic training for overall health. If anything, walking in nature can be a great exercise too!
  • Practice mindfulness to reduce stress levels – Stress increases intestinal permeability, slows down digestion (increasing risk of constipation and overgrowths), and reduces the vagus nerve connection. Implement stress reduction strategies like journaling, yoga, meditation, or nature walks to help support your emotional and mental health! Stress puts your body in fight or flight mode- the last thing your body is going to do when it thinks a tiger is running at is to prioritize a healthy gut!
  • Get plenty of quality sleep – Getting at least 8.5-9 hours of sleep and going through 3-5 REM cycles per night is essential for keeping your gut microbiome and circadian rhythm in balance. Lack of sleep can reduce your microbiome diversity, as well as increase insulin resistance, slow down your motility, and make you tired and moody!
  • Avoid smoking and excessive alcohol consumption – Toxic chemicals inhaled from cigarette smoke and from overconsumption of alcohol, can make the intestinal environment less inhabitable for good gut microbes. Limit or avoid these activities as much as possible to support a healthy gut.  Smoking and alcohol can both contribute to intestinal permeability, increased risk of gastritis and ulcers, and disrupt your gut microbiota.
  • Take antibiotics only when necessary – Antibiotics not only rid the body of illness-causing pathogenic bacteria, but good bacteria in the gut as well. To prevent this and the negative effects they can have on your immune and digestive health, avoid utilizing antibiotics for infections when not completely necessary. Reducing antibiotic use when not needed will also help to prevent antibiotic resistance!

Gut questions? LOL My team and I are here to help!

Contact us for help or check out my book – “The Women’s Guide to Hormonal Harmony” to learn more about your gut, digestion, hormones, and metabolism.

Join The Conversation