Department of Pharmacognosy, School of Pharmacy, The University of Mississippi, 38677 University, USA.
Int J Food Microbiol. 2010 Jun 15;140(2-3):175-82. doi: 10.1016/j.ijfoodmicro.2010.03.038. Epub 2010 Apr 2.
We have examined the gut bacterial metabolism of pomegranate by-product (POMx) and major pomegranate polyphenols, punicalagins, using pH-controlled, stirred, batch culture fermentation systems reflective of the distal region of the human large intestine. Incubation of POMx or punicalagins with faecal bacteria resulted in formation of the dibenzopyranone-type urolithins. The time course profile confirmed the tetrahydroxylated urolithin D as the first product of microbial transformation, followed by compounds with decreasing number of phenolic hydroxy groups: the trihydroxy analogue urolithin C and dihydroxylated urolithin A. POMx exposure enhanced the growth of total bacteria, Bifidobacterium spp. and Lactobacillus spp., without influencing the Clostridium coccoides-Eubacterium rectale group and the C. histolyticum group. In addition, POMx increased concentrations of short chain fatty acids (SCFA) viz. acetate, propionate and butyrate in the fermentation medium. Punicalagins did not affect the growth of bacteria or production of SCFA. The results suggest that POMx oligomers, composed of gallic acid, ellagic acid and glucose units, may account for the enhanced growth of probiotic bacteria.
我们使用 pH 控制、搅拌、批量培养发酵系统，模拟人体大肠的远端区域，研究了石榴副产物（POMx）和主要的石榴多酚，安石榴苷的肠道细菌代谢。将 POMx 或安石榴苷与粪便细菌孵育会生成二苯并吡喃酮型尿石素。时程曲线证实四羟基尿石素 D 是微生物转化的第一个产物，其次是酚羟基数量减少的化合物：三羟基类似物尿石素 C 和二羟基尿石素 A。POMx 暴露增强了总细菌、双歧杆菌和乳杆菌的生长，而不影响梭菌科 coccoides-Eubacterium rectale 群和 C. histolyticum 群。此外，POMx 增加了发酵培养基中短链脂肪酸（SCFA）的浓度，如乙酸盐、丙酸盐和丁酸盐。安石榴苷不会影响细菌的生长或 SCFA 的产生。结果表明，由没食子酸、鞣花酸和葡萄糖单元组成的 POMx 低聚物可能是益生菌生长增强的原因。
