title: Intake of a fermented soymilk beverage containing moderate levels of isoflavone aglycones enhances bioavailability of isoflavones in healthy premenopausal Japanese women: a double-blind, placebo-controlled, single-dose, crossover trial.
abstract: This study aimed to investigate the bioavailability of serum isoflavones after the intake of soymilk fermented by Lactobacillus casei strain Shirota containing 32.5% isoflavone aglycones (FSM) or placebo soymilk containing no isoflavone aglycones (SM). In a double-blind, placebo-controlled, single-dose, crossover trial, 7 healthy premenopausal Japanese women (mean age: 35.3 ± 11.0) consumed FSM or SM on day 1 and crossed over to the other soymilk after a 6-day washout period. Serum isoflavones in blood samples collected at 0, 1, 2, 3, 4, and 5 hr after intake were analyzed by liquid chromatography coupled with tandem mass spectrometry. The area under the curve (AUC) values for the serum concentrations of genistein and total isoflavones were significantly higher, by about 1.4-fold, up to 5 hr after FSM intake compared with SM intake (each p<0.05), and that of daidzein tended to be higher after FSM intake. In addition, AUC analysis of total isoflavones for individual subjects revealed that 5 out of 7 subjects had higher AUC values after FSM intake compared with SM intake and that the 2 remaining subjects had similar AUC values. These 2 subjects had higher AUC values after SM intake (mean, 2,502 ± 348) than those of the other subjects (mean, 1,158 ± 269). These results indicate that the bioavailability of isoflavones, especially genistein, is enhanced after the intake of FSM containing 32.5% isoflavone aglycones compared with intake of SM containing no isoflavone aglycones and that the enhancement is observed in healthy premenopausal Japanese women whose isoflavone absorption capacity is low after SM intake.
authors: Yakult Central Institute, 5-11 Izumi, Kunitachi-shi, Tokyo 186-8650, Japan.
authors: Takayuki
authors: T
authors: Nagino
authors: Yakult Central Institute, 5-11 Izumi, Kunitachi-shi, Tokyo 186-8650, Japan.
authors: Mitsuyoshi
authors: M
authors: Kano
authors: Yakult Central Institute, 5-11 Izumi, Kunitachi-shi, Tokyo 186-8650, Japan.
authors: Norie
authors: N
authors: Masuoka
authors: Yakult Central Institute, 5-11 Izumi, Kunitachi-shi, Tokyo 186-8650, Japan.
authors: Chiaki
authors: C
authors: Kaga
authors: Yakult Honsha Co., Ltd., 1-1-19 Higashi-shinbashi, Minato-ku, Tokyo 105-8660, Japan.
authors: Michitoshi
authors: M
authors: Anbe
authors: Yakult Central Institute, 5-11 Izumi, Kunitachi-shi, Tokyo 186-8650, Japan.
authors: Kouji
authors: K
authors: Miyazaki
authors: Nutrition Clinic of Kagawa Nutrition University, 3-24-3 Komagome, Toshima-ku, Tokyo 170-8481, Japan.
authors: Keiko
authors: K
authors: Kamachi
authors: Nutrition Clinic of Kagawa Nutrition University, 3-24-3 Komagome, Toshima-ku, Tokyo 170-8481, Japan.
authors: Mariko
authors: M
authors: Isozaki
authors: Nutrition Clinic of Kagawa Nutrition University, 3-24-3 Komagome, Toshima-ku, Tokyo 170-8481, Japan.
authors: Chigusa
authors: C
authors: Suzuki
authors: Nutrition Clinic of Kagawa Nutrition University, 3-24-3 Komagome, Toshima-ku, Tokyo 170-8481, Japan.
authors: Chikako
authors: C
authors: Kasuga
authors: Nutrition Clinic of Kagawa Nutrition University, 3-24-3 Komagome, Toshima-ku, Tokyo 170-8481, Japan.
authors: Akira
authors: A
authors: Tanaka
keywords: area under the curve; bioavailability; fermented soymilk; isoflavone aglycone; pharmacokinetics; premenopausal women