Andrieux C, Sacquet E
Reprod Nutr Dev (1980). 1983;23(2a):259-71. doi: 10.1051/rnd:19830210.
For 4 weeks, 3-month old germfree (GF) and conventional (CV) rats were given a semi-synthetic diet sterilized by irradiation with or without 10% of lactose. During the 5th week, 0.2% of titanium oxide (TiO2) was added to the diet and the rats were killed at regular intervals throughout the light/dark cycle. The patterns of TiO2 and 45Ca excretion were similar, indicating that TiO2 was a good marker of unabsorbed calcium transit. The apparent absorption coefficient of calcium, magnesium and phosphorus was determined in the ileum, caecum, large intestine and faeces by the mineral/TiO2 ratio. The effects of microflora and lactose varied with the mineral and the digestive tract level studied. --In the small intestine, microflora had no effect on the apparent absorption of calcium and magnesium but did have an unfavorable influence on phosphorus absorption. Lactose increased calcium and magnesium absorption, and this increase was similar in GF and CV rats, but lactose had a favorable effect on phosphorus absorption only in CV rats. --In the caecum, microflora had an unfavorable effect on the apparent absorption of calcium and magnesium and a favorable effect on phosphorus absorption. The ingestion of lactose reduced calcium and magnesium absorption in the caecum of GF rats and phosphorus absorption in the caecum of CV animals. --In the colon, mineral absorption was not significant in either CV or GF rats receiving the lactose-free diets. Lactose ingestion caused the absorption of calcium, magnesium and phosphorus to rise significantly only in GF rats. This absorption contributed to the stronger effect of lactose on total calcium and phosphorus absorption in GF rats.
持续4周，给3月龄无菌（GF）和普通（CV）大鼠喂食经辐照灭菌的半合成饲料，饲料中添加或不添加10%的乳糖。在第5周，向饲料中添加0.2%的二氧化钛（TiO₂），并在整个明暗周期内定期处死大鼠。TiO₂和⁴⁵Ca的排泄模式相似，表明TiO₂是未吸收钙转运的良好标志物。通过矿物质/TiO₂比值测定回肠、盲肠、大肠和粪便中钙、镁和磷的表观吸收系数。微生物群和乳糖的影响因所研究的矿物质和消化道水平而异。——在小肠中，微生物群对钙和镁的表观吸收没有影响，但对磷的吸收有不利影响。乳糖增加了钙和镁的吸收，GF大鼠和CV大鼠的这种增加相似，但乳糖仅对CV大鼠的磷吸收有有利影响。——在盲肠中，微生物群对钙和镁的表观吸收有不利影响，对磷的吸收有有利影响。摄入乳糖降低了GF大鼠盲肠中钙和镁的吸收以及CV动物盲肠中磷的吸收。——在结肠中，接受无乳糖饲料的CV大鼠和GF大鼠的矿物质吸收均不显著。摄入乳糖仅使GF大鼠的钙、镁和磷吸收显著增加。这种吸收促成了乳糖对GF大鼠总钙和磷吸收的更强作用。
