Prebiotics - bacterial substrates that are just as important as probiotics

While the essential role played by probiotics in intestinal health and the immune system is now well-known, the importance of prebiotics, which in a variety of ways, complete the effectiveness of probiotic strains, is sometimes neglected.

Prebiotics can be defined as non-digestible food ingredients that selectively stimulate the growth or activity of bacteria in the colon in ways that are likely to improve health.

Prebiotics include inulin, especially fructo-oligosaccharides (FOS) or oligofructosides which are fructose chains (not necessarily, as in the case of oligosaccharides, derived from inulin) that end with a unit of glucose.

These sources of fermentable fibre selectively feed beneficial bacteria in intestinal microbiota called bifidobacteria. They are thus said to be highly bifidogenic.
A number of human studies have shown that ingestion of FOS produces significant changes to intestinal flora, characterised by increased bifidobacteria colonisation and lower counts of clostridia, enterobacteria and bacteroides.

This stimulation of the bifidobacteria population improves intestinal comfort. As demonstrated by more than 100 scientific and medical studies, doses of 2.5 grams upwards of FOS a day have led to multiple metabolic changes:

- Immunomodulatory effects : FOS support the intestinal immune system by boosting the function of the intestinal barrier. In addition, by increasing bifidobacteria colonies, they modulate various parameters of immunity including activation of lymphocytes and macrophages and production of antiobodies (IgAs) as well as increasing resistance to infection by pathogenic organisms.
- Nutritional benefits by improving final-stage digestion : FOS boost intestinal absorption of certain minerals such as calcium and magnesium, as well as substances such as isoflavones, thus improving bone mineral density.
- Stimulation of short-chain fatty acid (SCFA) formation, particularly the nutrient butyrate, a major fuel for colonocytes, that has a protective effect against carcinogenesis, and proprionate which has a beneficial effect on sugar and fat metabolism. These SCFAs help maintain the integrity of colonic mucosa and stimulation of water and electrolyte exchange across the colon wall, and regulate bacterial interaction.
- A decrease in the pH of the colon , by stimulating production of acetic and lactic acids, the combination of which maintains a healthy environment by inhibiting growth of potentially pathogenic bacteria.
- A significant reduction in enzyme activity such activity being associated with formation of carcinogens such as beta-glucuronidase, nitro-reductase, glycocholic-hydroxylase acid and azoreductase.
- Finally, according to studies [1] conducted on rats with human flora, fermentation of FOS alters the profile of mucin secretion which could help protect against certain diseases such as chronic colitis.

Supplementing with prebiotics in the form of fructo-oligosaccharides therefore offers real health benefits beyond just improvements to digestive comfort. Taken alone, or in conjunction with probiotics, FOS can be incorporated into everyone’s daily diet, whether or not they suffer from any digestion-related disease. According to the health authorities, there is currently no scientific reason to oppose daily supplementation with these beneficial prebiotics.

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[1] Hoebler, C., Michel, C., Meslin, J. C., Vabre, S., Gaudier, E., and Cherbut, C. (2002). Effet de la fermentation des fructo-oligosides sur la distribution des mucines et l'épaisseur du gel de mucus. Nutr Clin Metab 16 (Suppl 1), 19S.