What is the science behind Prebiotics?
Prebiotics have become increasingly popular in recent years as people become more aware of the importance of a healthy gut microbiota. Prebiotics are dietary fibres that are indigestible by humans but can be fermented by beneficial gut bacteria. In this article, we'll explore the science behind prebiotics, how they work, and their potential health benefits.
What are Prebiotics?
Prebiotics are non-digestible dietary fibres that are found naturally in a variety of foods, including fruits, vegetables, and whole grains. They are essentially food for the beneficial bacteria in our gut, known as probiotics. Prebiotics promote the growth and activity of these beneficial bacteria, which can help to maintain a healthy gut microbiota. The most commonly studied prebiotics are fructooligosaccharides (FOS), inulin, and galactooligosaccharides (GOS) which are part of the same family as oligosaccharide. These prebiotics are found in foods such as garlic, onions, leeks, bananas, asparagus, chicory root, and whole grains.
How do Prebiotics Work?
Prebiotics work by selectively stimulating the growth and activity of beneficial gut bacteria, while inhibiting the growth of harmful bacteria. When we consume prebiotics, they pass through the stomach and small intestine undigested and are then fermented by the bacteria in the colon. The fermentation process produces short-chain fatty acids (SCFAs), such as butyrate, propionate, and acetate. SCFAs provide an energy source for the cells lining the colon, and they also play a role in regulating inflammation in the gut. Prebiotics also promote the growth of beneficial bacteria such as Bifidobacterium and Lactobacillus, which have been associated with a range of health benefits, including improved digestion, enhanced immune function, and protection against pathogenic bacteria.
Potential Health Benefits of Prebiotics
Improved Digestive Health
Prebiotics can help to improve digestive health by promoting the growth of beneficial bacteria and enhancing the production of SCFAs. This can lead to a reduction in inflammation and a lower risk of digestive issues such as irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD).
Enhanced Immune Function
Prebiotics can also help to enhance immune function by promoting the growth of beneficial bacteria and reducing the growth of harmful bacteria. The beneficial bacteria in our gut play a vital role in regulating the immune system and protecting us against pathogens.
Improved Heart Health
Prebiotics may also help to improve heart health by reducing inflammation and promoting healthy cholesterol levels. SCFAs, which are produced during the fermentation of prebiotics, have been shown to reduce cholesterol levels and lower the risk of heart disease.
Reduced Risk of Type 2 Diabetes
Prebiotics may also help to reduce the risk of type 2 diabetes by improving insulin sensitivity and blood sugar control. A study published in the British Journal of Nutrition found that supplementing with prebiotics improved insulin sensitivity in overweight and obese adults.
Improved Mental Health
Some studies have shown that the gut microbiota interacts with parts of the central nervous system, including the brain. From this it has been suggested that the use of prebiotics could improve mental functioning.
Overall, prebiotics are an important dietary fibre that can be found naturally in a variety of foods. They work by selectively promoting the growth of beneficial gut bacteria, which can have a range of potential health benefits, including improved digestive health, enhanced immune function, improved heart health, reduced risk of type 2 diabetes, and improved mental function. If you're interested in learning more about prebiotics and the science behind them, a range of scientific journal articles have been referenced below.
References:
Gibson, G.R. and Roberfroid, M.B. (1995) “Dietary modulation of the human colonic microbiota: Introducing the concept of prebiotics,” The Journal of Nutrition, 125(6), pp. 1401–1412. Available at: https://doi.org/10.1093/jn/125.6.1401
Davani-Davari, D. et al. (2019) “Prebiotics: Definition, types, sources, mechanisms, and clinical applications,” Foods, 8(3), p. 92. Available at: https://doi.org/10.3390/foods8030092
Megur, A. et al. (2022) “Prebiotics as a tool for the prevention and treatment of obesity and diabetes: Classification and ability to modulate the gut microbiota,” International Journal of Molecular Sciences, 23(11), p. 6097. Available at: https://doi.org/10.3390/ijms23116097
“The effects of probiotics and Prebiotics on Mental Disorders: A review on depression, anxiety, alzheimer, and autism spectrum disorders” (2020) Current Pharmaceutical Biotechnology, 21. Available at: https://doi.org/10.2174/13892010mtazkntii0