Development changes to gut microflora metabolism in mice.
Developmental changes in the activities of bacterial nitrate reductase, nitroreductase and beta-glucuronidase and their response to fermentable dietary fibre, were investigated in caecal contents from suckling mice (2-week-old) and in mice aged 4-24 weeks fed either a purified fibre-free diet or that diet supplemented with 5% (w/w) pectin. There was no apparent age-related trend common to the three enzymes studied. Nitrate reductase activity in the mice fed the fibre-free diet did not markedly alter with age. Pectin administration, however, was associated with a significant increase in nitrate reductase activity, particularly in 4-week-old mice. Nitroreductase activity exhibited an overall upward trend in mice from 2 to 12 weeks and thereafter decreased. Caecal beta-glucuronidase activity in mice increased sharply between 2 weeks and 4 weeks of age, thereafter not changing significantly until the 24th week. Pectin feeding had no consistent effect on activities either of nitroreductase or beta-glucuronidase. The changes in enzyme activities with age were not related to the concentration of bacteria in the caecum, which was highest in the 2-week-old mice. We conclude that the weaning is a period in which marked changes in caecal bacterial enzyme activities can occur.
Brennan-Craddock
W E
WE
BIBRA, Toxicology International, Carshalton, Surrey, UK.
Mallett
A K
AK
Rowland
I R
IR
Neale
S
S
D000375:Aging; D000818:Animals; D000833:Animals, Suckling / Q000254:growth & development* / Q000382:microbiology*; D001419:Bacteria / Q000201:enzymology / Q000378:metabolism*; D001835:Body Weight; D002432:Cecum / Q000254:growth & development / Q000378:metabolism / Q000382:microbiology*; D004043:Dietary Fiber / Q000494:pharmacology; D005260:Female; D005966:Glucuronidase / Q000032:analysis; D051379:Mice; D008807:Mice, Inbred BALB C; D050901:Nitrate Reductase; D009565:Nitrate Reductases / Q000032:analysis; D009579:Nitrobenzoates / Q000378:metabolism
D004043:Dietary Fiber; D009579:Nitrobenzoates; D009565:Nitrate Reductases; D050901:Nitrate Reductase; D005966:Glucuronidase; C008629:4-nitrobenzoic acid