British Journal of Nutrition

Full Papers

Microbiology

Determination of the in vivo prebiotic potential of a maize-based whole grain breakfast cereal: a human feeding study

Andrew L. Carvalho-Wellsa1 c1, Kathrin Helmolza2, Cecelia Nodeta2, Christine Molzera2, Clare Leonarda3, Brigid McKevitha3, Frank Thieleckea3, Kim G. Jacksona1 and Kieran M. Tuohya2

a1 Nutrition Research Group, Department of Food and Nutritional Sciences, School of Chemistry, Food and Pharmacy, University of Reading, Reading RG6 6AP, UK

a2 Food and Microbial Sciences Unit, Department of Food and Nutritional Sciences, University of Reading, Reading RG6 6AP, UK

a3 CPUK, Albany Place, Welwyn Garden City, Herts AL7 1RR, UK

Abstract

Epidemiological studies have shown an inverse relationship between risk of CVD and intake of whole grain (WG)-rich food. Regular consumption of breakfast cereals can provide not only an increase in dietary WG but also improvements to cardiovascular health. Various mechanisms have been proposed, including prebiotic modulation of the colonic microbiota. In the present study, the prebiotic activity of a maize-derived WG cereal (WGM) was evaluated in a double-blind, placebo-controlled human feeding study (n 32). For a period of 21 d, healthy men and women, mean age 32 (sd 8) years and BMI 23·3 (sd 0·58) kg/m2, consumed either 48 g/d WG cereal (WGM) or 48 g placebo cereal (non-whole grain (NWG)) in a crossover fashion. Faecal samples were collected at five points during the study on days 0, 21, 42, 63 and 84 (representing at baseline, after both treatments and both wash-out periods). Faecal bacteriology was assessed using fluorescence in situ hybridisation with 16S rRNA oligonucleotide probes specific for Bacteroides spp., Bifidobacterium spp., Clostridium histolyticum/perfringens subgroup, Lactobacillus–Enterococcus subgroup and total bacteria. After 21 d consumption of WGM, mean group levels of faecal bifidobacteria increased significantly compared with the control cereal (P = 0·001). After a 3-week wash-out period, bifidobacterial levels returned to pre-intervention levels. No statistically significant changes were observed in serum lipids, glucose or measures of faecal output. In conclusion, this WG maize-enriched breakfast cereal mediated a bifidogenic modulation of the gut microbiota, indicating a possible prebiotic mode of action.

(Received November 23 2009)

(Revised March 01 2010)

(Accepted April 22 2010)

(Online publication May 21 2010)

Correspondence:

c1 Corresponding author: Dr A. L. Carvalho-Wells, fax +44 118 931 0080, email a.l.wells@rdg.ac.uk

Footnotes

Abbreviations: NWG, non-whole grain (placebo); WG, whole grains; WGM, maize-derived WG

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