How can sugar impact gut bacteria?

Most of us are aware of the impact of excessive amounts of sugar on our health, but how much do we understand about the impact of sugar on gut bacteria in our microbiome and how this links to overall health? And do we know how to ensure we are not eating too much?

What is sugar?

Sugar comes in a variety of formats and is not simply the white substance that we find in most kitchens today.

• Sucrose is ‘everyday’ sugar that is added to hot drinks or sprinkled on cereal and is a combination of fructose and glucose. Although it comes from a natural product (sugar cane), it is a refined food, which contains 390 kilocalories per 100g and no nutrients
• Glucose is the sugar found in carbohydrates and is used by the body for energy
• Fructose is a natural sugar found in fruits, fruit juices, certain vegetables (such as carrots) and honey and is extremely sweet
• Galactose is a simple sugar found in dairy products, avocados, sugar beets and gums. The main dietary source is lactose from milk and yogurt, which is digested to galactose and glucose
• Lactose is made up of galactose and glucose. It is the sugar found in milk and milk products
• Maltose is a sugar produced by the breakdown of starch in wheat, corn, barley and other grains. It is also found in some fruits, particularly peaches and pears

How does sugar impact the gut?

Whilst the research on sugar’s effects on the gut microbiome is limited, there is evidence that a standard Western diet causes changes that are detrimental to the health of the bacteria in our gut and to our gut wall generally. This diet contains high levels of processed foods and sugar and has been linked to obesity. There is also evidence that the microbiomes of obese and overweight people differ to those of normal weight individuals.

Sugar has been linked to inflammation, which has been shown to contribute to many of the diseases we face in society today.

One way that sugar has been shown to contribute to inflammation in the body is by causing changes in the bacteria in the gut microbiome, affecting both the diversity of bacteria types and their function. Specifically, a high intake of dietary sugar has been linked to an increased abundance of Proteobacteria (pathogenic bacteria types) and a decrease in beneficial Bacteroidetes. Sugar is mostly digested in the small intestine, but when we consume an excess, the sugar is not completely absorbed and is then available to be used by the bacteria in the large intestine where it is preferentially used by the pathogenic species, allowing them to proliferate.

By affecting the gut microbiome, high sugar intake has also been shown to affect its role in immune regulation.

Excess sugar has also been shown to impact the integrity of the gut wall, potentially contributing to a condition called ‘leaky gut’. This is also known as intestinal permeability and it allows undigested particles and toxins to pass through the gut wall into the bloodstream, causing inflammation.

What can we do to reduce sugar intake and support gut health?

On average, in the UK we eat around 22 teaspoons of sugar every day, whilst the maximum intake recommended by the NHS in the UK is 5-7 teaspoons. This equates to 24g or just over five teaspoons for children and 30g or just over seven teaspoons for adults. 

Did you know that a single can of coke contains around nine teaspoons of sugar, 150ml of orange juice has more than three, one chocolate digestive contains 1.5 teaspoons, one Milky Way has five, one teaspoon of jam contains a whole teaspoon of sugar and one small block of ice cream contains 8.5?

Most of this sugar intake is hidden under many different names in processed and packaged foods. There are more than 50 (and some say 75) different names used to label sugar, but they all contribute empty calories to our food and impact our gut health. They include the following:

1. Dextrose
2. Frucose
3. Galactose
4. Glucose
5. Lactose
6. Maltose
7. Sucrose
8. Agave nectar
9. Barley malt
10. Beet sugar
11. Cane juice
12. Cane sugar
13. Caramel
14. Carob syrup
15. Castor sugar
16. Coconut sugar
17. Corn sweetener
18. Corn syrup
19. D-ribose
20. Date sugar
21. Demerara sugar
22. Dextrin
23. Diastase
24. Ethyl maltol
25. Evaporated cane sugar
26. Fruit juice
27. Fruit juice concentrate
28. High fructose corn syrup
29. Honey
30. Malt
31. Malt syrup
32. Maltodextrin
33. Maltol
34. Mannose
35. Maple syrup
36. Molasses
37. Muscovado
38. Nectar
39. Palm sugar
40. Rice syrup

So the next time you are buying food, take some time to examine the ingredients on anything that is pre-packed to identify the potential sources and amounts of sugar in each of the products you are buying. Look out for any of the names listed above and if there are more than two or three, try and find a substitute product with less sugar.

By doing this, you will be positively impacting your friendly bacteria in your gut – a side effect of high sugar intake that you may have never previously considered.

If you would like to know more about the impact of sugar on gut bacteria, check out these articles:

• Sugar can keep good microbes from colonising your gut – PBS Organisation
• Adaptation of the gut microbiota to modern dietary sugars and sweeteners – Academic
• The connection between sugar and your gut – Psychology Today

Want to know more?
ProVen Probiotics aim to provide the best support for both you and your health. If you wish to know more about gut health please do not hesitate to call us on 01639 825107 or alternatively, learn more via our blogs or in-depth ProVen research.

ProVen Probiotics, Unit 2 Christchurch Road, Baglan Industrial Park, Port Talbot, SA12 7DJ. Tel: 01639 825107