What are sorbitol and mannitol?

Sorbitol and mannitol are types of “sugar alcohols”, also known as polyols. They are naturally found in a range of fruit and vegetables, and can also be added to diet versions of food and drinks.

How are they digested?

Polyols (sorbitol and mannitol) are poorly digested by many people. These sugars are partly absorbed into the blood by passive diffusion in the small intestine. A person’s transit time (how long food stays in the digestive tract) and the molecular size of the sugar will influence how much is absorbed.

Due to their very small size, these sugars have the ability to draw water into the small intestine (this also can happen with undigested fructose and lactose), resulting in watery diarrhea. After that, undigested sorbitol or mannitol will finally reach the large intestine, where the gut microbes will start to break them down into gases (like hydrogen) and other beneficial fermentation products (like Short Chain Fatty Acids – SCFAs).

What are the common symptoms associated with poor digestion of polyols?

Even small doses of sugar alcohols can result in diarrhea, bloating, and increased flatulence, in particular in people with IBS. It is important to identify your unique tolerance, as this can vary considerably from person to person.

Can I test this myself?

If you suspect that you have an issue with sorbitol or mannitol, you can use breath testing to measure your intolerance. You can find out more about the FoodMarble breath analysis device and app here.

We also have a “6-week discovery plan“, which you can use with the breath analysis device to find which foods suit you best. In 6 weeks you will test your tolerance to 4 hard-to-digest food components (FODMAPs); lactose, fructose, sorbitol, and inulin. You’ll get guided through the whole process using the app.

Sorbitol and Mannitol in Food

Examples of vegetables containing sorbitol

• Aubergine – 75g is low FODMAP
• Green beans – 75g is low FODMAP
• Bok choy – 75g is low FODMAP
• Sweet corn – 75g is high FODMAP

Examples of vegetables containing mannitol

• Butternut squash – 75g contains moderate FODMAPs
• Cauliflower – 75g is high FODMAP
• Celeriac – 75g is low FODMAP
• Celery – 75g is high FODMAP
• Fennel, bulb – 75g contains moderate FODMAPs
• Leek, leaves – 75g contains moderate FODMAPs
• Button mushrooms – 75g is high FODMAP
• Snow peas – 75g is high FODMAP

Examples of fruits containing sorbitol

• Apple (fresh) – 160g (one apple) is high FODMAP
• Apricot – 70g (two apricots) is high FODMAP
• Avocado – 80g (half an avocado) is high FODMAP
• Blackberries – 160g is high FODMAP
• Coconut – 95g contains moderate FODMAPs
• Nectarine – 150g is high FODMAP
• Peach (contains both sorbitol and mannitol) – 145g is high FODMAP
• Plum – 65g is high FODMAP

Examples of fruits containing mannitol

• Peach (contains both sorbitol and mannitol) – 145g is high FODMAP
• Watermelon (mannitol) – 150g is high FODMAP