Sugar Craving : Gut Bacteria

Who's craving sugar, you or your gut bacteria?

Sugar Craving : Gut Bacteria could be more to blame than you think. Discover how your gut bacteria can cause you to crave certain foods.

One of the most often complained about aspects of the keto diet, or any diet, is that even when things are going well,  you suddenly blow it.

Without warning, you  can find yourself craving something not on the food list.

You may have happily gone along with all the rules of your chosen eating plan, and been delighted as the weight fell off.

Plus, if you’re on a low carb or keto diet, you’ve probably learned to cook all kinds of new and tasty things.

But then something happens.

One minute you’re loving your cauliflower crust pizza with extra cheese, and the next minute you want to kill for a cookie.

Or a cake, a pie, a bar of chocolate, a mountain of ice cream…..


What turns us from a diet hero into a sugar beast in seconds: gut bacteria

Sugar Craving : Gut Bacteria

There are of course many theories about this.

They range from the plausible sounding “you’re missing out on a vital nutrient” to the frankly unhelpful “you have no will power”

Certainly there is evidence that a deficiency in Magnesium can cause you to seek magnesium containing foods.

These are foods such as nuts, seeds, beans and dark leafy greens.

These foods may help make your cravings subside, and it is probably worth trying a magnesium supplement to see if this is true in your case.

Other reasons offered include the idea that we’re designed to crave sugar and have an inbuilt liking for sweet things.

Actually, there is probably some merit to this.

In ancient times, fruits ripened in the summer or autumn. It would have made sense to eat all we could of these before the onset of winter.

Due to the fact that sugar was a seasonal treat, there would have been little need for us to develop an aversion to over eating anything sweet that we managed to forage.

Also, you need to take care of your sleep and relaxation. Both are important if you are to have a healthy and diverse gut microbe environment.

However, some of us (most of us) seem to go beyond this normal fondness for sweet things. We actually crave something sweet, like a drug addict who’s gone too long without their favourite chemical.

So, what do we know about why this should be? Is there any science that can shine a light on our addictive behavior towards sugar?

Are we biologically programmed to seek out sugar like a starving wasp or is something else responsible for our behavior?

The role of  gut microbes in craving certain foods.

Sugar Craving : Gut Bacteria

This study suggests that we aren’t as in control of our cravings as is generally thought.

The authors suggest that the microbes in our gut are determined to survive by manipulating us into eating the sort of foods that they need to thrive.

These microbes also want us to eat the types of foods that will be damaging to the competing microbes.

The study sought to understand the processes by which the microbes could get us to go along with what they want, even if it was not in our best interests to do so.

Sugar Craving : Gut Bacteria

It’s a fight between them and us, and unfortunately we are seriously outnumbered.

It is estimated that we carry within our guts up to 2kg of these microbes. Their genes outnumber our own genes by 100 to 1.

In this study it was hypothesized that when there was a less diverse population of microbes, one microbial population would be able to dominate.

They call the shots when it came to manipulating the host (you) into ingesting whatever it was they want.

This imbalance of the microbiota is called dysbiosis, and can cause many health issues such as IBS as well as produce food cravings.

When the gut microbes were more diverse, it would not be so easy for one population to do this.

What do our resident microbes (gut bacteria) like to eat?

The probiotic bifidobacteria thrive on dietary fiber. (1) while Prevotella feast on carbohydrates. (2). Bacteroides like both protein and animal fats.

However, our microbes don’t get everything to go their own way.

What we eat, and how often we eat can have very dramatic effects on the numbers and diversity of our microbes in our gut.

It has been demonstrated that gut populations can change within 24 hours of us changing our dietary habits.

This would make sense of the often noted side effect of any new diet we embark on.

Within days of a big change, there is often a strong increase in our level of craving for a particular sort of food.

In the past, this was dismissed as “missing” that particular food.

However, the craving could also be a symptom of our particular group of microbes noticing the lack of their favourite foods.

Following this, they send you a strong signal to start eating that food again.

Those among us who crave sugar may possibly have more of the sugar loving microbes than people who can take or leave anything sweet.

This research looked into the possible causes of “chocolate desiring” behavior as opposed to “chocolate indifferent”.

This study also turned its attention to our fondness for dark chocolate.

It seems that there is a strong link between food cravings and the diversity and type of our gut microbes.

So, is it us or our gut microbes that crave the sugar?

It would seem that we are driven to crave sugar by our microbes, especially the Prevotella strain.

When they sense a loss of their favourite foods, carbohydrates, they are able to influence both our mood and our cravings.

They do this in order to get us feasting on just the nutrients they need.

They pull us towards the sugar laden goodies by:

  • Changing your taste receptors so that you prefer the taste of sweet foods.
  • Changing your hormones so that you feel hungry even when you do not need more food.
  • Stimulating the Vagus nerve which will cause over eating.
  • Rewarding you with a big dose of dopamine after you’ve eaten something sweet.

In this sense, it appears that our microbes have the upper hand. However, while there is little we can do about our craving, there are things that we can do take back control of our eating habits.

What to do when a sugar crave hits

Sugar Craving : Gut Bacteria

The first thing to do is recognize a craving for sugar for what it is.

It is controlled by our microbes, and so giving into this craving will only serve to make our microbes stronger.

By eating that slice of cake or chocolate, our prevotella microbes are able to thrive and multiply.

They become stronger and more able to assert their needs once they have colonized to a point where they outnumber all the other microbes.

Giving in to the craving will only ensure that we continue to have the same craving.

Worse,  it will become ever stronger as we continue to feed the microbes sending us the message.

If you eat some chocolate in the hope that it will make the craving “go away”, you will soon find that the opposite is true.

There is only one way to stop a sugar crave.

Don’t give in. Don’t feed the microbes that want the sugar, and they will die.

How to declare war on the sugar eating microbes

The quickest way to start killing off the microbes that are making you into a sugar eating beast is to give up sugar completely.

Choose a day and stop, if you give in, you will crave sugar even more.

Apart from making you gain weight, sugar is also a major trigger of inflammation in your body. This dangerous inflammation leads to multiple health issues.

Avoid artificial sweeteners, as they are damaging to your health. If you need to use a sugar substitute choose something natural such as erythritol.

If you’re not too sure about the dangers of inflammation read What is inflammation in the body?

Simple carbs will need to be eliminated from your diet. These carbs include bread, flour products, pasta, potatoes and rice.

Simple carbs are turned into sugar in your body, and will help your bad microbes to thrive.

You can also get the upper hand by increasing the amount of fats and protein that you eat.

This will encourage the growth of other types of microbes. This in turn will make it more difficult for one particular type to call the shots when it comes to what you want to eat.

It’s particularly beneficial to take a probiotic. Probiotics are able to increase the diversity of our gut microbes.

Sauerkraut and unsweetened keifer are great high-quality probiotic foods.

Another great product is collagen supplements.

More usually thought of as being great for the skin and nails, collagen also helps to boost your gastric juices.

By doing this it helps to restore the integrity and health of the gut’s lining.

Collagen also contains important amino acids that are key to repairing a damaged intestinal lining.

The added protein will help you to feel less hungry, and feed the good microbes in your gut.

Intermittent fasting and gut bacteria

Intermittent fasting has also been shown to have an effect on gut microbes. Fating  will alter the diversity, improving your health as well as reducing food cravings.

Avoid ready meals

Most ready meals should be avoided as they contain emulsifiers. Emulsifiers keep the texture of the food consistent but they cause disruption of the gut microbes.

This leads to a reduction in the diversity of the microbes and causes them to send out different signals to your body.

The take home message

You may be surprised by the strength of your sugar craving a few days into your new diet regime.

Most people blame the fact that you’re now not eating some of your old favorites, and you’re missing them.

However, it’s important to remember that it’s more than likely that the culprits are your gut microbes.

Once you know this, you’ll understand why the system of eating just one of whatever it is you’re craving rarely works.

By continuing to feed your body simple carbohydrates, especially sugar, you will be feeding the microbes that are already causing you to experience the craving.

This has two important effects on your gut health:

  • Your carbohydrate (sugar) loving microbes will thrive and dominate.
  • Other microbes will suffer, and your gut microbe diversity is negatively affected. This will cause you many health issues.

The most effective way to over come sugar cravings is to keep away from all sugars, simple carbohydrates and processed foods.

It will take a few weeks to restore gut health, but you will begin to feel the effects in just 24 hours.

As you kill off the culprits, you will notice that the craving goes away.

You will also notice several health benefits as the overall health of you gut improves in direct relation to the diversity of your gut returning to a healthy level.

Sugar craving has nothing to do with being weak willed, or having a sweet tooth.

Stop the sugars and take back control of all your eating decisions.

You may also be interested in:

What is inflammation in the body?

How many carbs can you have on a keto diet (making sure you’re eating the right ones)


Collagen supplements





  1. That’s interesting. Actually, I’m not a sugar fan, I prefer salty food hihi. I learned many things through your post and I found it pretty cool. I have one question though: when you’re talking about sugar, is it only the « bad » sugar or also the sugar from fruits? Because in my sense sugar from fruits is good, am I wrong?
    Thanks for sharing this information. 🙂

    1. Hi Audrey,

      Thanks for your comment.

      Sugar is not good for you and can be a major cause of chronic inflammation.

      Chronic inflammation is the trigger for many health problems and something you’d definitely want to avoid.

      The sugars in fruits are the same and most fruits are off the menu if you’re following the keto diet.

      However, if you are eating low carb then some fruits can be included in your diet.

      Fruits contain many healthful nutrients. The issue isn’t with fruit per se but rather with the fact that they can be eaten in excess.

      We evolved at a time when fruits were a seasonal treat, and necessary before the winter.

      Now, with fruit being available all year round it’s important that we consider the carb (sugar) count as we would with any other food.

      I hope this answers your question.

      Best wishes,


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