can’t be ignored — just talk to any nutrition enthusiast. As such, probiotics and prebiotics are sky-rocketing in popularity.
Probiotics and prebiotics are often misunderstood. Probiotics (sometimes called microbiotics) are foods or supplements that contain a source of live, beneficial bacteria; prebiotics, instead, provide sustenance to these bacteria. The human body cannot break down prebiotics.
As more and more people opt for a probiotic supplement to give their gut flora a quick, convenient helping hand, prebiotics have been getting more attention, too. This is because some probiotic supplements include a type of prebiotic, such as fructooligosaccharides — or FOS.
When it comes to prebiotics, there are both benefits and downsides that you should be aware of. So, what’s the verdict on FOS? If I want the healthiest, happiest gut possible, should I choose a probiotic with FOS?
What are fructooligosaccharides (FOS)?
Fructooligosaccharides are a form of water-soluble carbohydrate. Composed of short fructose chains, they cannot be digested by the human body. As well as being considered a prebiotic, FOS are commonly used as an alternative sweetener in certain foods and even used as a medicine.
FOS occurs naturally in some plants, including asparagus, onion, leeks, bananas, garlic and Jerusalem artichoke. When used within a probiotic formula, it can serve as sustenance for probiotic bacteria. Because they are non-digestible, they have no effect on blood sugar levels.
While FOS come with their own health benefits, they also have some side effects, which is why probiotics with FOS are not always the best choice for everyone.
What are fructooligosaccharides (FOS) used for?
Because of their ability to act as food for friendly bacteria, FOS often feature in the ingredients list of probiotic supplements. Low calorie and with a sweet taste, FOS are also commonly used as a sweetener; they can even be made into syrups or used as a coffee alternative.
As prebiotics in probiotic supplements
Complex fructooligosaccharides are prebiotics — a type of fibre that our bodies cannot break down, but that bacteria can. FOS pass through our intestines to be digested by our gut microbes; these bacteria then turn FOS into short-chain fatty acids and vitamins.
This is why you’ll often find FOS in probiotic products — those products marketed as containing helpful, beneficial ‘friendly’ bacteria for our bodies.
As an alternative sweetener and food
Fructooligosaccharides are listed as dietary ingredients and can improve food taste and texture. Although they are carbohydrates, they are normally listed as a fibre. Because of their subtle sweet flavour, FOS are often used as a low-calorie sugar alternative.
Some types of FOS are made into syrups — such as blue agave syrup — whereas others can be ground down into a powder and used as a coffee alternative, such as ground chicory root. FOS can be made into extracts of varying concentrations.
As a medicine
Fructooligosaccharides also have some uses in medicine as a treatment for constipation, as well as having been used for treating traveller’s diarrhea, osteoporosis and high cholesterol levels. It is also understood that FOS can aid immunity and bone health.
What foods contain fructooligosaccharides (FOS)?
Fructooligosaccharides occur naturally in many different types of plant:
- Jerusalem artichokes
- Blue agave
- Yacon root
As well as being derived from cane sugar and seaweed, FOS can also be produced in a laboratory.
What are the health benefits of fructooligosaccharides (FOS)?
There are a number of potential known benefits to consuming FOS, spanning their potentially amplifying effects on probiotic bacteria.
Giving probiotics a helping hand
Passing through our bodies, FOS remain undigested until they reach the colon, where they are broken down by bacteria, stimulating their growth and production. This is why they are often included in products that contain beneficial ‘friendly’ bacteria — like probiotic supplements.
Protection from unhealthy bacteria
Research has shown that
What are the potential side effects and risks of fructooligosaccharides (FOS)?
Incorporating FOS into your diet and choosing probiotics with FOS isn’t all good news — there are also some risks and side effects that you should consider. Some people may have a particular sensitivity to FOS.
Research confirms that
Aggravation of IBS
FOS has been studied for its impact on those who suffer from IBS. The currently available research shows mixed results; in one study of the impact of FOS in IBS sufferers, treatment with 20g of
So, should you take probiotics with fructooligosaccharides (FOS)?
Probiotics are available with FOS included, with the idea being that they will help the healthy bacteria to thrive. However, there are brands that decide to keep the FOS out of their probiotic formula — to protect those with a FOS sensitivity — and focus instead on choosing hardy, resilient bacteria that doesn’t rely on FOS to thrive in the gut.
Those with a sensitivity or those concerned about digestive symptoms — such as people with IBS — may want to avoid probiotics that contain FOS. If you do choose a probiotic that contains FOS, it is understood that many of the side effects can be mitigated by taking no more than 10g per day.
Choosing the right probiotic supplement for you
One brand who forgo FOS in their probiotics is