Chlorogenic acids (CGA) significantly increased the growth of some bacteria in the human large intestine, according to an in vitro study published in the British Journal of Nutrition.
Coffee was described as a rich source of the polyphenol and samples containing different levels of CGA were used in a pH-controlled model of the distal region of the human colon with incubated samples of human faecal microbiota.
The researchers found that the coffee with the highest CGA levels led to a significant increase in growth of Bifidobacterium when compared to the control ten hours after exposure.
CGA alone also induced a significant increase in the growth of the Clostridium coccoides–Eubacterium rectale group.
The commercial coffee samples used were: Nescafé Green Blend (80·8 mg CGA), Nescafé Gold Blend (33·9 mg CGA) and Nescafé Original (33·8 mg CGA). All contained similar levels of caffeine.
CGA was rapidly metabolised in four hours, dihydrocaffeic acid and dihydroferulic acid was produced and caffeine remained unmetabolised. These results suggested specific bacterial groups were capable of metabolising CGA.
The researchers from the University of Reading in the UK said further in vivo researcher was needed to confirm the results but these initial findings pointed to CGA as a potential prebiotic in the human large intestine.
Source: British Journal of Nutrition
Published ahead of print, doi:10.1017/S0007114514003948
“In vitro colonic metabolism of coffee and chlorogenic acid results in selective changes in human faecal microbiota growth”
Authors: C. E. Mills, X. Tzounis, M. Oruna-Concha, D. S. Mottram, G. R. Gibson and J. P. E. Spencer