The gut microbiome is an important contributor to human health, shaped by many endogenous and exogenous factors. The gut microbiome displays sexual dimorphism, suggesting influence of sex hormones, and also has been shown to change with aging. Yet, little is known regarding the influence of menopause - a pivotal event of reproductive aging in women - on the gut microbiome. Here, we summarize what is known regarding the interrelationships of female sex hormones and the gut microbiome, and review the available literature on menopause, female sex hormones, and the gut microbiome in humans. Taken together, research suggests that menopause is associated with lower gut microbiome diversity and a shift toward greater similarity to the male gut microbiome, however more research is needed in large study populations to identify replicable patterns in taxa impacted by menopause. Many gaps in knowledge remain, including the role the gut microbiome may play in menopause-related disease risks, and whether menopausal hormone therapy modifies menopause-related change in the gut microbiome. Given the modifiable nature of the gut microbiome, better understanding of its role in menopause-related health will be critical to identify novel opportunities for improvement of peri- and post-menopausal health and well-being.
PMID 35983178 35983178 DOI 10.2147/IJWH.S340491 10.2147/IJWH.S340491 Peters et al. 2022, Peters 2022
Cite this article
Peters, B. A., Santoro, N., Kaplan, R. C., & Qi, Q. (2022). Spotlight on the Gut Microbiome in Menopause: Current Insights. International Journal of Women's Health. https://doi.org/10.2147/IJWH.S340491
Peters BA, Santoro N, Kaplan RC, Qi Q. Spotlight on the Gut Microbiome in Menopause: Current Insights. International Journal of Women's Health. 2022. doi:10.2147/IJWH.S340491
Ziv-Gal A et al., 2016·Reproductive toxicology (Elmsford, N.Y.)
During the menopausal transition, a woman's reproductive capacity declines, her hormone milieu changes, and her risk of hot flashes increases. Exposure to phthalates, which can be found in personal care products, can also result in altered reproductive function. Here, we investigated the associations between phthalate metabolite levels and midlife hot flashes. Eligible women (45-54 years of age) provided detailed information on hot flashes history and donated urine samples (n=195). Urinary phthalate metabolite levels were measured by HPLC-MS/MS. A higher total sum of phthalate metabolites commonly found in personal care products was associated with an increased risk of ever experiencing hot flashes (odds ratio (OR)=1.45; 95% confidence interval (CI)=1.07-1.96), hot flashes in the past 30days (OR=1.43; 95%CI=1.04-1.96), and more frequent hot flashes (OR=1.47; 95%CI=1.06-2.05). These data suggest that some phthalate exposures from personal care products are associated with menopausal hot flashes in women.
Prior et al., 2006·Journal of Reproductive and Infant Psychology·
Ordinary women and official statements confuse and conflate perimenopause—the long, complex, life phase of higher and chaotic estrogen levels—with the low and stable estrogen levels of menopause. This paints both perimenopause and menopause with an inaccurate ‘estrogen deficiency’ brush. Menopause is the hormonal, and (except for hot flushes) the experiential opposite of perimenopause. This feminist analysis is from my perspective as physician‐scientist who experienced a perimenopause that was scientifically enlightening, but personally agonizing. Denial of perimenopausal and menopausal differences causes perimenopause to be ‘lost’ in several ways: (1) we may assume that perimenopause is chronic rather than ending in a largely asymptomatic menopause; (2) societal taboos isolate us, depriving us of solidarity with perimenopause ‘survivors’; (3) we are told we have dropping estrogen levels when our experiences, like pregnancy dreams, tell us the opposite; (4) gynaecology treats heavy flow with estrogen despite higher perimenopausal estrogen levels; (5) feminists ignore hormonal changes and attribute perimenopausal symptoms to (real) stresses of inferior social status and ageing; and (6) many of us thus become menopausal without the unique, self‐actualization experience that perimenopause has the potential to provide. Thus perimenopause—a valuable transition into knowing and standing up for ourselves—becomes lost.
The median age at menopause in Western populations of women is approximately 51 years. While very late (i.e., after 54 years) menopause is exceedingly uncommon, a sizeable minority of women experience cessation of ovarian function at or prior to age 45. By convention, menopause that occurs at ages 40-45 is considered "early" and occurs in about 5% of women. Premature ovarian failure (POF) is reserved for the approximately 1% of women who experience hypergonadotropic amenorrhea prior to age 40 years. POF represents the end stage of a variety of disorders that result in the loss of ovarian follicles. Depending upon the age at diagnosis, the probability of a genetic, autoimmune, or idiopathic cause will be more or less likely. Two functioning X chromosomes appear necessary for normal ovarian function. The most obvious genetic cause of POF is Turner Syndrome, in which a complete or near-complete loss of the second X chromosome occurs. Turner Syndrome typically results in the most severe and irreversible POF, often clinically evident prior to menarche. Typically, in Turner Syndrome, menopause precedes menarche, and there is no evidence of ovarian function. However, cases with multiple tissues diagnosed as 45, X have been reported to result in ovarian function and even pregnancy. It is likely that mitigating factors, perhaps autosomal, can modify this most severe and irreversible cause of ovarian failure. Lesser degrees of ovarian failure have also been attributed to partial X chromosome deletions and milder degrees of X chromosome mosaicism. Fragile X syndrome is another example of mild POF that can be linked to disorders of the X chromosome. Other genetic defects are believed to cause POF, yet their prevalence has been difficult to determine. The localization of the gene for the blepharophimosis/ptosis/POF Syndrome has been recently reported, yet this finding has not been seen commonly in POF. Other genetic syndromes including POF await elucidation. Many transgenic "knock-out" animals have been created with deficient ovarian function. Most interesting along these lines is the heterozygous FSH receptor knock-out, which exhibits a reduced follicle reserve and early ovarian depletion. Application of this knowledge and translation of these transgenic experiments into elucidation of clinical disease has been difficult, but represents an area of tremendous potential progress in the understanding of the pathogenesis of POF. Another approach to the genetics of POF has been to examine the genome of affected and unaffected individuals. The genetics appear to differ greatly depending upon the timing of the expression of the POF. For example, women with early menopause are more likely to possess the PVUII polymorphic allele for estrogen receptor alpha. Whether or not this polymorph is more common in women with earlier menopause, i.e., POF, is unclear. Pedigree data indicate that early menopause and premature menopause sort similarly within families. The only difference between women with true POF and those with early menopause may be in the timing of the expression of the syndrome, and not in the genetics. Population genetic approaches analyzing affected and unaffected individuals are underway in several research centers and represent another area of progress. Immune and other, idiopathic causes of POF await further clarification. It is clear that this is an area of great research potential. Understanding how ovaries fail may assist women with this disorder by facilitating the development of novel therapies. Additionally, such information will provide important clues about optimizing ovarian function in individuals without POF who are seeking extension of their reproductive life spans or fertility enhancement by other means.
Cycle Across the Lifespan · Cycle and General Health
Bouchard TP et al., 2026·Journal of ovarian research·
Open Access
Reproductive hormones of the fertile window are often referenced to women in regular cycles, but this may not be representative of the hormonal profiles of women in different circumstances like polycystic ovarian syndrome, the postpartum period, and the perimenopause transition. This observational cohort study sought to identify the variability in the reproductive hormones in various clinical circumstances and to establish potential thresholds for each category based on hormone measurements with the Mira urinary hormone monitor. A total of 57 women (ages 22-51) in various circumstances (regular cycles, polycystic ovarian syndrome, postpartum and perimenopause) tracked Mira urine hormone measurements (estrone-3-glucuronide, luteinizing hormone, pregnanediol glucuronide), contributing 444 cycles of data. Using additive mixed models, hormone values were stratified by the four different reproductive categories. The perimenopause and polycystic ovarian syndrome groups demonstrated relative hypoestrogenic states, while the perimenopause group showed low luteal pregnanediol glucuronide and the polycystic ovarian syndrome/polyendocrine metabolic ovarian syndrome (PCOS/PMOS) group showed high luteal pregnanediol glucuronide. The perimenopause group had significantly higher luteinizing hormone values throughout the whole cycle. The fertile window hormone thresholds vary depending on a woman's specific reproductive category. Women in different circumstances should not necessarily use the same hormonal thresholds for the fertile window and ovulation. A larger dataset with ultrasound correlation to ovulation is required to delineate the fertile window with more precision. Hormone differences across the menstrual cycle could be used for targeted treatments in polycystic ovarian syndrome and perimenopause women.