Kerry E. Wangen

Probiotic capsules do not lower plasma lipids in young women and men.

Objective:To investigate the effect of probiotic capsules on plasma lipids.Design:A randomized, single-blinded, placebo-controlled, parallel-arm trial.Subjects:Fifty-five normocholesterolemic subjects ages 18–36 (33 premenopausal women and 22 men).Intervention:Each subject consumed either three probiotic capsules each containing a total of 109 colony-forming units Lactobacillus acidophilus and Bifidobacterium longum and 10–15 mg fructo-oligosaccharide or three placebo capsules daily for 2 months (men) or two menstrual cycles (women). Plasma lipids were measured before and following the intervention (during the early follicular phase for women).Results:Plasma concentrations of total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and triglyceride were not altered by consumption of probiotic or placebo capsules and were not different between treatment groups following the intervention.Conclusions:These results do not support a beneficial effect of Lactobacillus acidophilus strain DDS-1 and Bifidobacterium longum strain UABL-14 on plasma lipids in normocholesterolemic young women and men.Sponsorship:Supported by the Minnesota Agricultural Experiment Station and UAS Laboratories.

Consumption of Lactobacillus acidophilus and Bifidobacterium longum do not alter urinary equol excretion and plasma reproductive hormones in premenopausal women

Objective: To confirm the results of an earlier study showing premenopausal equol excretors to have hormone profiles associated with reduced breast cancer risk, and to investigate whether equol excretion status and plasma hormone concentrations can be influenced by consumption of probiotics.Design: A randomized, single-blinded, placebo-controlled, parallel-arm trial.Subjects: In all, 34 of the initially enrolled 37 subjects completed all requirements.Intervention: All subjects were followed for two full menstrual cycles and the first seven days of a third cycle. During menstrual cycle 1, plasma concentrations of estradiol (E2), estrone (E1), estrone-sulfate (E1-S), testosterone (T), androstenedione (A), dehydroepiandrosterone-sulfate (DHEA-S), and sex-hormone-binding globulin (SHBG) were measured on cycle day 2, 3, or 4, and urinary equol measured on day 7 after a 4-day soy challenge. Subjects then received either probiotic capsules (containing Lactobacillus acidophilus and Bifidobacterium longum) or placebo capsules through day 7 of menstrual cycle 3, at which time both the plasma hormone concentrations and the post-soy challenge urinary equol measurements were repeated.Results: During menstrual cycle 1, equol excretors and non-excretors were not significantly different with respect to subject characteristics, diet, or hormone concentrations. Significant inverse correlations were found between E2 and body mass index (BMI) (P=0.02), SHBG and BMI (P=0.01), DHEA-S and dietary fiber (P=0.04), and A and protein:carbohydrate ratio (P=0.02). Probiotic consumption failed to significantly alter equol excretor status or hormone concentrations during menstrual cycle 3, although there were trends towards decreased concentrations of T (P=0.14) and SHBG (P=0.10) in the probiotic group.Conclusions: We were unable to verify a previously reported finding of premenopausal equol excretors having plasma hormone concentrations different from those of nonexcretors. Furthermore, a 2-month intervention with probiotic capsules did not significantly alter equol excretion or plasma hormone concentrations.

Lack of effect of isoflavonic phytoestrogen intake on leptin concentrations in premenopausal and postmenopausal women

OBJECTIVE To assess the effect of soy isoflavone ingestion on plasma leptin concentrations in premenopausal and postmenopausal women. DESIGN Randomized, crossover studies, with blinding of participants and laboratory personnel. SETTING Procedures involving free-living individuals were carried out at the University of Minnesota General Clinical Research Center. PATIENT(S) Fourteen regularly cycling premenopausal women, and 18 postmenopausal women. INTERVENTION(S) Each premenopausal participant consumed, on a daily basis, each of three soy protein powders containing different levels of isoflavones for three menstrual cycles plus 9 days, with plasma samples collected every other day the last 6 weeks of each diet period. Similarly, each postmenopausal participant consumed each of the three powders for 93 days, with plasma samples collected daily on days 64 to 66 and 92 to 94 of each diet period. The powders, dosed on a per-kilogram body weight basis, provided mean isoflavone intakes of 8, 65, and 130 mg/day, for the control, low-isoflavone, and high-isoflavone diet periods, respectively. MAIN OUTCOME MEASURE(S) Plasma leptin concentrations. RESULT(S) Isoflavone intake had essentially no effect on leptin concentrations in either premenopausal or postmenopausal participants. Concentrations in the premenopausal women were higher during the periovulatory and midluteal phases as compared to the early follicular and midfollicular phases. CONCLUSION(S) Despite the well-documented effect of estrogens to enhance leptin production, even high levels of isoflavone consumption do not alter leptin concentrations in women. Further studies are needed to more precisely delineate the nature of estrogenic and/or antiestrogenic effects of isoflavones in humans.

Consumption of isoflavone-rich soy protein does not alter homocysteine or markers of inflammation in postmenopausal women.

Background/Objective:To investigate the effect of soy protein containing isoflavones on homocysteine (Hcy), C-reactive protein (CRP), soluble E-selectin (sE-selectin), soluble vascular adhesion molecule-1 (sVCAM-1) and soluble intercellular adhesion molecule-1 (sICAM-1).Subject/Methods:In a randomized crossover design, 34 postmenopausal women consumed soy protein isolate (26±5 g protein containing 44±8 mg isoflavones per day) or milk protein isolate (26±5 g protein per day) for 6 weeks each. Fasting blood samples were collected at the end of each diet period and end points analyzed by enzyme-linked immunosorbent assay.Results:Concentrations of Hcy, CRP, sE-selectin, sVCAM-1 and sICAM-1 were not different between soy and milk diet treatments. Results did not differ by equol production status or by baseline lipid concentration. Adjustment for intake of folate and methionine did not alter the Hcy results.Conclusions:These data suggest that decreasing vascular inflammation and Hcy concentration are not likely mechanisms by which soy consumption reduces coronary heart disease risk.