Unknowingly we have been consuming prebiotic foods for eons. Anyone who was breastfed as an infant has consumed prebiotics that have altered their gut microbiome in a beneficial way. Recently prebiotics have taken the front stage as a gut boosting health supplement.
This article will unpack a number of prebiotic review papers and outline when, how and why you might want to consume them.
“Prebiotics are short-chain carbohydrates that alter the composition, or metabolism, of the gut microbiota in a beneficial manner. It is therefore expected that prebiotics will improve health in a way similar to probiotics, whilst at the same time being cheaper, and carrying less risk and being easier to incorporate into the diet than probiotics (1)”
What an excellent way to start a review paper. How could I not dig deeper!
What Is A Prebiotic
Prebiotics, loosely defined, are carbohydrates that escape digestion in the small intestine, wind up in the large intestine and are fermented by the different bacteria that make up our microbiome (2). Many of our most numerous beneficial bacteria that reside in the colon, Lactobacilli and Bifidobacterium specifically, are primarily carbohydrate-fermenting bacteria, plus they contain no known pathogens. Feeding them the food that they love to eat/ferment raises their numbers (1).
To look for further validation on the benefits of prebiotics we can look again to breastfed infants. Not surprisingly, thanks to mom’s prebiotic and probiotic containing milk their microbiome is dominated by Bifidobacteria. A benefits of this situation is pathogen resistance as well as immune modulation (1).
Many carbohydrates escape digestion and end up feeding the microbes in our colon. One of the more studied prebiotic carbohydrates is the oligosaccharide family.
- Fructooligosaccharide (FOS)
- Galacto-oligosaccharides (GOS)
There are a range of other prebiotic foods including resistant starch such as green bananas, potato starch, many different fibers including psyllium husks and taro.
Benefits of Prebiotic Foods
The resulting benefit of increasing the numbers and activity of many beneficial gut microbes is the product of their fermentation. Short chain fatty acids (SCFAs), notably butyric acid, are produced and contribute considerable health benefits including energy for the cell walls lining the colon (epithelium). Currently butyrate is being explored for possible anti-inflammatory and anticarcinogenic properties (3).
Being acidic, SCFAs lower the PH of the colon, making it harder for many pathogenic bacteria including E. coli, Clostridia, Campylobacter, Salmonella, and Shigella to take hold and grow (4).
When To Take a Prebiotic
It is generally recommended to start small and ease your way up. Start with a fraction of the recommended dose, go low and slow. Any bloating, gas, stomach cramps, irregular bowel movements even headaches and brain fog can be a sign that something is imbalanced in your gut microflora. That or you may not tolerate the particular prebiotic food in question.
Personally I would prefer to screen the gut first with a CDSA. Then go to work on building it up with prebiotics, probiotics, fermented foods and bone broth. More on gut testing here.
References and Resources
- Review article: prebiotics in the gastrointestinal tract.
- A Prebiotic Substance Persistently Enhances Intestinal Calcium Absorption and Increases Bone Mineralization in Young Adolescents
- Review article: the role of butyrate on colonic function.
- Bioactive Food as Dietary Interventions for Liver and Gastrointestinal Disease
- Recommended GI testing – CDSA + PCR