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.


METHODS
A randomized, single-blinded, placebo-controlled, parallel-arm trial.


METHODS
In all, 34 of the initially enrolled 37 subjects completed all requirements.


METHODS
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 (E(2)), estrone (E(1)), estrone-sulfate (E(1)-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 E(2) 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.
Bonorden
M J L
MJ
Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN 55108, USA.
Greany
K A
KA
Wangen
K E
KE
Phipps
W R
WR
Feirtag
J
J
Adlercreutz
H
H
Kurzer
M S
MS
D000328:Adult; D001644:Bifidobacterium; D015992:Body Mass Index; D001943:Breast Neoplasms / Q000097:blood; D019314:Dehydroepiandrosterone Sulfate / Q000097:blood; D004043:Dietary Fiber / Q000378:metabolism; D060754:Equol; D004958:Estradiol / Q000097:blood; D005260:Female; D006728:Hormones / Q000097:blood*; D006801:Humans; D007529:Isoflavones / Q000652:urine*; D007779:Lactobacillus acidophilus; D008597:Menstrual Cycle / Q000097:blood / Q000502:physiology*; D048789:Phytoestrogens / Q000652:urine*; D017697:Premenopause / Q000378:metabolism*; D019936:Probiotics / Q000008:administration & dosage*; D012307:Risk Factors
C007610:4',7-dihydroxy-3,4-dihydroisoflavone; D004043:Dietary Fiber; D006728:Hormones; D007529:Isoflavones; D048789:Phytoestrogens; D004958:Estradiol; D060754:Equol; D019314:Dehydroepiandrosterone Sulfate