Dr. Ron’s Research Review – March 27, 2019


This week’s research review focuses on riboflavin as a novel prebiotic.

Besides the acceptance of all non-digestible carbohydrates as ‘true’ prebiotics, several non-carbohydrate structures such as polyphenols, minerals or vitamins that can exert beneficial effects through the modulation of the gut microbiota may qualify as prebiotics.  (Steinert et al., 2016)
Vitamins or other antioxidants that have redox-mediating functions may possess powerful prebiotic effects. When they are in an oxidized state, they may accept electrons from microbial metabolism, whereas in a reduced state they may donate electrons to reduce oxygen to water or reduce other electron acceptors that eventually lower the redox potential.
Oxygen stress is one of the main stressors for strict anaerobic bacteria, such as F. prausnitzii.  F. prausnitzii can survive in moderately oxygenized environ- ments by exploiting extracellular antioxidants such as riboflavin and cysteine (usually abundantly present in the gut) to transfer electrons to oxygen to lower the redox potential. The use of riboflavin by F. prausnitzii is a potential new function of this vitamin.
A small group of adult volunteers were supplemented with 100 mg riboflavin for 14 days. The number of F. prausnitzii per gram of feces increased during supplementation, and the number dropped again, although not to the baseline levels, after a 1-week washout period. In addition to this increase, there was an increase in another group of anaerobes, namely Roseburia species, and a decrease in E. coli, indicating an improvement in the anaerobic conditions and redox state in the gut.


Dr. Ron




The prebiotic concept and human health: a changing landscape with riboflavin as a novel prebiotic candidate
(Steinert et al., 2016) Download
Emerging evidence suggests that the gut microbiota has a critical role in both the maintenance of human health and the pathogenesis of many diseases. Modifying the colonic microbiota using functional foods has attracted significant research effort and product development. The pioneering concept of prebiotics, as introduced by Gibson and Roberfroid in the 1990s, emphasized the importance of diet in the modulation of the gut microbiota and its relationships to human health. Increasing knowledge of the intestinal microbiota now suggests a more comprehensive definition. This paper briefly reviews the basics of the prebiotic concept with a discussion of recent attempts to refine the concept to open the door for novel prebiotic food ingredients, such as polyphenols, minerals and vitamins.


Steinert, RE, et al. (2016), ‘The prebiotic concept and human health: a changing landscape with riboflavin as a novel prebiotic candidate’, Eur J Clin Nutr, 70 (12), 1348-53. PubMed: 27380884