Woods M N, Goldman P
J Nutr. 1979 May;109(5):738-43. doi: 10.1093/jn/109.5.738.
It has been suggested that the metabolic activity of the intestinal microflora is necessary for the utilization of the alpha-keto and alpha-hydroxy analogues of the essential amino acids. This role of the intestinal microflora has been examined by comparing weight gain of germfree and conventional rats in response to the substitution of one amino acid in the diet by its analogue. Using a completely defined liquid diet it was found that weight gain of germfree rats was well maintained and comparable to that of conventional rats when 1.5 M equivalents of DL-alpha-hydroxyisocaproic acid was substituted for L-leucine in the diet. Although weight gain was not fully maintained when 2.0 M equivalents of L-phenyllactate was substituted for L-phenylalanine, germfree and conventional rats showed similar weight gains. These results exclude an obligatory role for the flora in the utilization of these non-nitrogen containing analogues of L-phenylalanine and L-leucine.
有人提出，肠道微生物群的代谢活性对于必需氨基酸的α-酮和α-羟基类似物的利用是必要的。通过比较无菌大鼠和普通大鼠在饮食中用一种氨基酸的类似物替代该氨基酸后的体重增加情况，对肠道微生物群的这一作用进行了研究。使用完全确定的液体饮食，发现当饮食中用1.5摩尔当量的DL-α-羟基异己酸替代L-亮氨酸时，无菌大鼠的体重增加得到了很好的维持，与普通大鼠相当。虽然当用2.0摩尔当量的L-苯乳酸替代L-苯丙氨酸时体重增加没有完全维持，但无菌大鼠和普通大鼠的体重增加相似。这些结果排除了微生物群在利用这些L-苯丙氨酸和L-亮氨酸的非含氮类似物方面的必需作用。
