How do prebiotic supplements work?

Prebiotic supplements work by providing the gut microbiota with specific types of fibers that are not digested by the human body, but instead, are fermented by gut bacteria. This fermentation process leads to the production of short-chain fatty acids (SCFAs) such as acetate, propionate, and butyrate, which are known to have many health benefits.

Prebiotic supplements typically contain specific types of fibers such as human milk oligosaccharides (HMO), inulin, fructooligosaccharides (FOS), galactooligosaccharides (GOS), and resistant starch.

1. Inulin: This is a soluble fiber found in many plants such as chicory root, Jerusalem artichoke, and dandelion greens. It is commonly used in prebiotic supplements due to its ability to selectively stimulate the growth of beneficial bacteria in the gut.
2. Fructooligosaccharides (FOS): These are also soluble fibers found in many plants such as onions, garlic, and bananas. They are commonly used in prebiotic supplements due to their ability to increase the growth of Bifidobacteria in the gut.
3. Galactooligosaccharides (GOS): These are soluble fibers found in human milk and some legumes. They are commonly used in prebiotic supplements due to their ability to increase the growth of Bifidobacteria and Lactobacilli in the gut.
4. Resistant starch: This is a type of starch that is not digested in the small intestine but instead ferments in the large intestine. It is found in foods such as green bananas, cooked and cooled potatoes, and lentils. It is commonly used in prebiotic supplements due to its ability to increase the production of butyrate in the gut.
5. Lactulose: This is a synthetic sugar that is commonly used as a prescription laxative but also has prebiotic properties. It is not digested in the small intestine but instead ferments in the large intestine, increasing the growth of beneficial bacteria such as Bifidobacteria.
6. Human milk oligosaccharides (HMOs): HMOs are a type of prebiotic that are naturally present in human breast milk. They are not digested in the human small intestine but instead pass into the large intestine, where they selectively stimulate the growth of beneficial bacteria such as Bifidobacteria. HMOs have been shown to have a variety of health benefits, including improving gut health, reducing the risk of infections, and promoting the development of a healthy immune system in infants. HMOs have also been found to have anti-inflammatory properties and may help to prevent the development of certain chronic diseases.

These fibers are not digested in the upper gastrointestinal tract and pass through to the colon where they are fermented by gut bacteria. This fermentation process creates a favorable environment for the growth of beneficial bacteria such as Bifidobacteria and Lactobacilli, which have been associated with numerous health benefits such as improved gut health, enhanced immune function, and reduced inflammation.

In addition to promoting the growth of beneficial bacteria, prebiotic supplements have also been shown to increase the production of SCFAs, particularly butyrate, which is important for maintaining gut barrier function, reducing inflammation, and protecting against colorectal cancer.

References:

1. Slavin J. Fiber and prebiotics: mechanisms and health benefits. Nutrients. 2013 Apr 22;5(4):1417-35. doi: 10.3390/nu5041417. PMID: 23609775; PMCID: PMC3705355.
2. Bode L. Human milk oligosaccharides: prebiotics and beyond. Nutr Rev. 2009 Jan;67 Suppl 2:S183-91. doi: 10.1111/j.1753-4887.2009.00239.x. PMID: 19549265; PMCID: PMC2808026.
3. Jantscher-Krenn E, Bode L. Human milk oligosaccharides and their potential benefits for the breast-fed neonate. Minerva Pediatr. 2012 Jun;64(3):227-43. PMID: 22648364; PMCID: PMC4269242.