Cholecalciferol supplementation alters gut function and improves digestibility in an underground inhabitant, the naked mole rat (Heterocephalus glaber), when fed on a carrot diet.
Naked mole rats (Heterocephalus glaber) lead a strictly subterranean existence and appear to be naturally deficient in cholecalciferol (D3). Oral supplementation with D3 (Ds) led to a 1.8-fold increase in food intake and the associated enlargement (1.4-fold) of the caecum. The effect of Ds, and the concomitant increase in food intake, on caecal fermentation efficiency when animals were fed on a carrot-based diet was determined by measuring the rate of both gas production and short-chain fatty acid (SCFA) production. Microbial-controlled fermentation processes in the caecum were enhanced with Ds when compared with animals not receiving a D3 supplement (Dn). Both the rates of gas production (Dn 10.76 (SE 0.77), Ds 15.20 (SE 1.77) ml/g dry matter (DM) per h) and SCFA production (Dn 463.0 (SE 33.7), Ds 684.3 (SE 74.8) mumol/g DM per h) increased more than 1.4-fold per g DM caecal substrate. These factors contributed to the higher digestibility of the food in Ds animals. The larger quantity of energy available to D3-replete naked mole rats was not used in anabolic processes, for these animals maintained mass. These findings suggest that metabolic rate in D3-replete animals was elevated. Thus, despite improved gut function, D3-replete animals may be disadvantaged by their higher energy and food requirements in their natural milieu.
Department of Paediatrics, University of the Witwatersrand, Baragwanath Hospital, Johannesburg, South Africa.
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Yahav
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Buffenstein
D000818:Animals; D002432:Cecum / Q000378:metabolism; D002762:Cholecalciferol / Q000008:administration & dosage*; D004063:Digestion / Q000502:physiology; D004435:Eating / Q000502:physiology*; D005232:Fatty Acids, Volatile / Q000378:metabolism; D005285:Fermentation / Q000502:physiology; D005740:Gases; D008297:Male; D012377:Rodentia / Q000502:physiology*
D005232:Fatty Acids, Volatile; D005740:Gases; D002762:Cholecalciferol