Association between equol producers and type 2 diabetes mellitus among Japanese older adults.

AIMS/INTRODUCTION: Equol, which is produced by enteric bacteria from soybean isoflavones, has a chemical structure similar to estrogen. Both in vivo and in vitro studies have shown the beneficial metabolic effects of equol. However, its effects on type 2 diabetes remain unclear. We investigated the association between the equol producers/non-producers and type 2 diabetes. MATERIALS AND METHODS: The participants included 147 patients with type diabetes mellitus aged 70-89 years, and 147 age- and sex-matched controls. To ascertain the equol producers or non-producers, we used the comparative logarithm between the urinary equol and daidzein concentrations (cut-off value -1.75). RESULTS: The urinary equol concentration was significantly lower in the diabetes group compared with the non-diabetes group (P = 0.01). A significant difference in the proportion of equol producers was observed among all participants (38.8% in the diabetes group and 53.1% in the non-diabetes group; P = 0.01). The proportion of equol producers among women was significantly lower in the diabetes group (31.4%) than in the non-diabetes group (52.8%; P < 0.01). Additionally, the frequency of dyslipidemia in female equol producers was significantly lower than that in female non-equol producers (P < 0.01). Among men, no such differences were observed. We found a significant positive correlation between the urinary equol and daidzein concentrations among equol producers (r = 0.55, P < 0.01). CONCLUSIONS: Our study findings showed that postmenopausal women had a low proportion of equol producers with diabetes and dyslipidemia.

Preventive effect of daikenchuto, a traditional Japanese herbal medicine, on onset of ileus after gynecological surgery for malignant tumors.

BACKGROUND: Postoperative ileus is a major complication of abdominal surgical procedures. The purpose of this study was to investigate preventive effect of daikenchuto (DKT) on onset of ileus in patients who received gynecological surgery for malignant tumors. METHODS: A total of 904 patients who received gynecological surgery for malignant tumors by opening retroperitoneum along with retroperitoneal lymph node dissection during a period between 2004 and 2018 were included in this retrospective study. The retroperitoneum was not sutured in all patients. Comparisons were made for proportion of patients developing ileus (frequency of postoperative ileus onset), timing of ileus onset, and treatment types for ileus among following three groups: a group treated with enema or laxatives to release gas if they did not pass the intestinal gas for 3 days postoperatively (Group A, n = 152); a group treated with adhesion-inhibitory absorptive barrier at the opening to the retroperitoneum (Group B, n = 188); and a group treated with adhesion-inhibitory absorptive barrier and oral intake of DKT 7.5 g per day (Group C, n = 564). RESULTS: The frequency of ileus onset significantly decreased in both Groups B (4.8%) and C (3.5%) compared to Group A (16.4%). Furthermore, the frequency of ileus onset was significantly less in Group C compared to Group B. For the treatment types, frequency of ileus, which was successfully treated only with conservative therapy, was the same for Groups B and C. However, incidence of serious ileus that required surgery decreased by 45% in Group C (2/564) compared to Groups A (2/152) and B (3/188). CONCLUSIONS: Results suggest that DKT prevents development of serious ileus after gynecological surgery for malignant tumors and therefore contributes to improvement in patients' QOL.

Daidzein Intake Is Associated with Equol Producing Status through an Increase in the Intestinal Bacteria Responsible for Equol Production.

Equol is a metabolite of isoflavone daidzein and has an affinity to estrogen receptors. Although equol is produced by intestinal bacteria, the association between the status of equol production and the gut microbiota has not been fully investigated. The aim of this study was to compare the intestinal bacteria responsible for equol production in gut microbiota between equol producer and non-producer subjects regarding the intake of daidzein. A total of 1044 adult subjects who participated in a health survey in Hirosaki city were examined. The concentration of equol in urine was measured by high-performance liquid chromatography. The relative abundances of 8 bacterial species responsible for equol production in the gut microbiota was assessed using 16S rRNA amplification. There were 458 subjects identified as equol producers. The proportion of equol production status and the intake of daidzein increased with age. Daily intake of daidzein was larger in equol-producer. The intestinal bacteria, which convert daidzein to equol were present in both equol producers and non-producers. However, the relative abundance and the prevalence of Asaccharobacter celatus and Slackia isoflavoniconvertens were significantly higher in equol producers than those in equol non-producers. The intestinal bacteria that convert daidzein to equol are present in not only the equol producers but also in the non-producers. The daidzein intake is associated with the equol production status through an increase of A. celatus and S. isoflavoniconvertens in the gut microbiota.

The prophylactic effects of a traditional Japanese medicine, goshajinkigan, on paclitaxel-induced peripheral neuropathy and its mechanism of action.

BACKGROUND: This study aimed to evaluate the prophylactic effect of goshajinkigan (GJG) on paclitaxel (PTX)-induced neuropathy and to elucidate the mechanism of action. RESULTS: There was a time-dependent irreversible decrease in pain threshold in PTX group. In PTX/GJG group, pain threshold showed changes in the same level as control. Electron microscope showed that although the ganglion cells of control and PTX/GJG groups were normal, degeneration of the nucleus and swelling of the mitochondria were observed in PTX group. Expression of transient receptor potential vanilloid 4 (TRPV4) gene in PTX group significantly increased compared with that in control and PTX/GJG groups. In TRPV4 knock-out mice, no PTX-induced hyperalgesia was observed, and there was no significant difference in pain threshold between the 3 groups. CONCLUSIONS: These results showed that PTX induced hyperalgesia by enhancing TRPV4 expression, and suggested that GJG might alleviate hyperalgesia by preventing degeneration of the ganglion cells and suppressing TRPV4 expression.