Food consumption was recorded and showed that in control periods each subject maintained a high fat
(approximately 40 per cent of daily calories) and moderate plant fibre (approximately 18 g/day) intake. Pectin and bran
decreased faecal bacterial a-glucosidase and P-glucuronidase activities, and pectin increased the stool concentration
and rate of formation of ammonia by faecal incubations in vitro, but fat supplementation was without consistent effect.
The results demonstrate that plant cell-wall components, but not dietary fat, significantly influenced the enzymic
activity of the faecal microflora from subjects maintaining a mixed dietary intake typical of the UK.