What are prebiotics? Types and health benefits
Last updated: February 22nd, 2024
Prebiotics are a big topic in nutrition these days. As with probiotics, their relationship with human health has gathered a lot of interest in recent years. Prebiotics are compounds derived from non-digestible carbohydrates that confer health benefits to the host by selectively stimulating the growth of intestinal bacteria.
What are prebiotics?
Prebiotics are non-digestible food ingredients that confer health benefits to the host by selectively stimulating the growth and/or activity of a limited number of our intestinal bacteria [1].
Fructo-oligosaccharides (FOS), galacto-oligosaccharides (GOS), and trans-galacto-oligosaccharides (TOS) are the most common prebiotics.
Fermentation of prebiotics by gut microbiota produces short-chain fatty acids (SCFAs), such as lactate, butyrate, and propionate. These SCFAs have multiple beneficial effects on the body and gut health, as SCFAs are small enough to enter blood circulation through gut cells.
The difference between probiotics and prebiotics is that, while probiotics are beneficial bacteria, prebiotics are the food for these bacteria. Both are important for human health, but they have different roles. Probiotics are live bacteria and prebiotics are compounds derived from non-digestible carbohydrates such as fibre.
What are the different types of prebiotics?
There are various types of prebiotics. These include:
• Fructans such as inulin and fructo-oligosaccharides (FOS) can promote directly or indirectly several bacterial species.
• Galacto-oligosaccharides (GOS) can greatly stimulate Bifidobacteria and Lactobacilli, as well as Enterobacteria, Bacteroidetes and Firmicutes to a lesser extent [2].
• Hemicellulose-derived oligosaccharides such as arabinoxylans. Arabinoxylans could produce a strong prebiotic activity, in particular bifidogenic.
• Starch and glucose-derived oligosaccharides, a type of starch resistant to small intestine digestion, can stimulate the production of butyrate, a short-chain fatty acid (SCFA) [3]. Polydextrose, a glucose-derived oligosaccharide, can also stimulate Bifidobacteria [4].
• Pectic oligosaccharides (POS): some oligosaccharides come from a polysaccharide called pectin. This type of oligosaccharide is called pectic oligosaccharide (POS).
• Non-carbohydrate oligosaccharides: although carbohydrates are more likely to meet the criteria to be considered prebiotics, there are other compounds not classified as carbohydrates, but that can be classified as prebiotics, such as some flavanols [5].
Did you know you can combine prebiotics and probiotics to create synbiotic dietary supplements? Read more about that here!
What are the health benefits of prebiotics?
Research shows that prebiotics have a beneficial effect on gut health, which is directly linked to overall well-being. In addition, prebiotics exert their positive effects via the following pathways:
• Microbiota support: prebiotics provide energy sources to gut microbiota. This way, they are able to modulate the function and composition of these microorganisms [6].
• Immune system modulation: SCFAs have multiple benefits for the immune system, such as increasing antibody responses towards pathogens [7].
• Colorectal cancer risk reduction: fermentation products of probiotics, such as butyrate, have possible protective effects against the risk of colorectal cancer [8].
• Infants gastrointestinal disorder prevention: prebiotics can redice the risk of development of necrotizing enterocolitis in preterm infants [9].
• Skin irritation conditions: the risk of development and the severity of atopic dermatitis [10, 11] could decrease after prebiotic intake.
• Cardiovascular diseases (CVD) risk reduction due to the potential of prebiotics to reduce inflammatory markers and improve lipid profile [7].
How can I add prebiotics to my diet?
Prebiotics play an important role in human health, so it is important to consume them. They can be found in foods that are high in fibre, such as vegetables, fruits, legumes and whole-grain products. Foods that are high in prebiotic fibre include:
• Wheat
• Soybeans
• Oats
• Bananas
• Tomatoes
• Berries
• Asparagus
• Garlic
• Leeks
• Onions
• Chicory
Another option to increase prebiotic intake is supplements, purchased in health food stores and online. They are usually available in capsule form, in powder blends or even in bars.
Prebiotics are generally considered safe. They can have some minor side effects, such as diarrhea, bloating and flatulence. However, prebiotics’ chain length is the main parameter related to the development of these side effects.
Prebiotics with a shorter chain length have more side effects because they ferment earlier and more rapidly, while longer chain prebiotics – such as arabinoxylans from wheat– ferment slowier.
