Menopause, the gut microbiome, and weight gain: correlation or causation?

Exploration of the association between menopausal symptoms, gastrointestinal symptoms, and perceived stress: survey-based analysis

OBJECTIVE

The study aimed to evaluate the relationship between menopausal symptoms, gastrointestinal symptoms, and experienced stress in women from premenopause to postmenopause.

METHODS

We conducted a cross-sectional study using an anonymous survey that included questions on demographics, health (gynecological, gastrointestinal), and lifestyle (physical activity, sleep, etc) factors, the Perceived Stress Scale (PSS), and the Menopause-Specific Quality of Life Questionnaire (MENQOL).

RESULTS

Data of 693 participants aged 50.1 ± 3.2 years were analyzed. We found that the MENQOL total score increased depending on the stages of reproductive aging ( P < 0.001) and positively correlated with PSS scores ( r = 0.47, P < 0.001). Age, reproductive stage, body mass index (BMI), PSS score, diagnosis of depression or anxiety disorder, physical activity, and frequency of defecation appeared to have significant association with the total MENQOL score ( P < 0.05). The analysis within separate MENQOL domains revealed that PSS score and diagnosis of depression or anxiety disorder were associated with higher scores in all MENQOL domains ( P < 0.05) except sexual. Physical activity and the values of the Bristol stool form scale were related to the vasomotor items ( P < 0.05). The frequency of defecation was an independent contributor to the psychosocial and sexual domains ( P < 0.05). BMI, physical activity, and frequency of defecation were associated with physical symptoms ( P < 0.05).

CONCLUSIONS

Perceived stress and some gastrointestinal symptoms in women were associated with menopausal symptoms. Reproductive stages, physical activity, BMI, and previously diagnosed depression or anxiety disorder were related to the intensity of menopausal symptoms. However, further research is needed to confirm the relationship between stress, gastrointestinal, and menopausal symptoms.

Fat mass, weight and body shape changes at menopause - causes and consequences: a narrative review

In addition to age-related weight gain, menopause adds additional challenges for women with the occurrence of significant metabolic alterations and central and visceral fat redistribution. The changes in body composition then influence risks of cardiovascular disease, metabolic disruption, cancer, fracture, lung disease, sexual dysfunction, mental health disorders and dementia. They may also heighten the severity of vasomotor symptoms. Treatment of these changes requires a flexible long-term strategy. This narrative review explores the pathogenesis of the metabolic changes at menopause and effective management options.

Cognitive Decline in Early and Premature Menopause

Early and premature menopause, or premature ovarian insufficiency (POI), affects 1% of women under the age of 40 years. This paper reviews the main aspects of early and premature menopause and their impact on cognitive decline. Based on the literature, cognitive complaints are more common near menopause: a phase marked by a decrease in hormone levels, especially estrogen. A premature reduction in estrogen puts women at a higher risk for cardiovascular disease, parkinsonism, depression, osteoporosis, hypertension, weight gain, midlife diabetes, as well as cognitive disorders and dementia, such as Alzheimer's disease (AD). Experimental and epidemiological studies suggest that female sex hormones have long-lasting neuroprotective and anti-aging properties. Estrogens seem to prevent cognitive disorders arising from a cholinergic deficit in women and female animals in middle age premature menopause that affects the central nervous system (CNS) directly and indirectly, both transiently and in the long term, leads to cognitive impairment or even dementia, mainly due to the decrease in estrogen levels and comorbidity with cardiovascular risk factors, autoimmune diseases, and aging. Menopausal hormone therapy from menopause to the age of 60 years may provide a "window of opportunity" to reduce the risk of mild cognitive impairment (MCI) and AD in later life. Women with earlier menopause should be taken care of by various specialists such as gynecologists, endocrinologists, neurologists, and psychiatrists in order to maintain their mental health at the highest possible level.

Exposure to oestrogen and risk of anastomotic leakage after colorectal cancer surgery - A clue to the different leak rates in men and women

BACKGROUND

Colorectal anastomotic leakage is consistently more common in men, regardless of tumour location. This fact is largely unexplained but might be a consequence of biological differences including hormonal exposure and not only related to anatomy.

METHODS

This was a retrospective, nationwide registry-based observational study of post-menopausal women operated for colorectal cancer with an anastomosis between 2007 and 2016. Hormonal exposure before surgery, as defined by prescribed drugs affecting oestrogen levels, was related to postoperative anastomotic leakage, using mixed-effects logistic regression models with adjustment for confounding. Odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were derived. In addition, separate estimates according to tumour location were computed, and a sensitivity analysis excluding topical oestrogen hormone exposure was conducted.

RESULTS

Some 16,535 post-menopausal women were included, of which 16.2% were exposed to drugs increasing oestrogen levels before surgery. In this exposed group compared to the unexposed, leak rates were 3.1 and 3.8%, respectively. After adjustment, a reduction of anastomotic leakage in the exposed group was detected (OR: 0.77; 95% CI: 0.59-0.99). This finding was largely attributed to the rectal cancer subgroup (OR: 0.55; 95% CI: 0.36-0.85), while the exclusion of topical oestrogen drugs further reduced the estimates of the main analysis (OR: 0.63; 95% CI: 0.38-1.02).

CONCLUSIONS

Anastomotic leakage rates are lower in women exposed to hormone replacement therapy before surgery for colorectal cancer, which might explain some of the difference in leak rates between men and women, especially regarding rectal cancer.

Menopause is associated with postprandial metabolism, metabolic health and lifestyle: The ZOE PREDICT study

BACKGROUND

The menopause transition is associated with unfavourable alterations in health. However, postprandial metabolic changes and their mediating factors are poorly understood.

METHODS

The PREDICT 1 UK cohort (n=1002; pre- n=366, peri- n=55, and post-menopausal females n=206) assessed phenotypic characteristics, anthropometric, diet and gut microbiome data, and fasting and postprandial (0-6 h) cardiometabolic blood measurements, including continuous glucose monitoring (CGM) data. Differences between menopausal groups were assessed in the cohort and in an age-matched subgroup, adjusting for age, BMI, menopausal hormone therapy (MHT) use, and smoking status.

FINDINGS

Post-menopausal females had higher fasting blood measures (glucose, HbA1c and inflammation (GlycA), 6%, 5% and 4% respectively), sugar intakes (12%) and poorer sleep (12%) compared with pre-menopausal females (p<0.05 for all). Postprandial metabolic responses for glucose_2hiauc and insulin_2hiauc were higher (42% and 4% respectively) and CGM measures (glycaemic variability and time in range) were unfavourable post- versus pre-menopause (p<0.05 for all). In age-matched subgroups (n=150), postprandial glucose responses remained higher post-menopause (peak_0-2h 4%). MHT was associated with favourable visceral fat, fasting (glucose and insulin) and postprandial (triglyceride_6hiauc) measures. Mediation analysis showed that associations between menopause and metabolic health indicators (visceral fat, GlycA_360mins and glycaemia (peak_0-2h)) were in part mediated by diet and gut bacterial species.

INTERPRETATION

Findings from this large scale, in-depth nutrition metabolic study of menopause, support the importance of monitoring risk factors for type-2 diabetes and cardiovascular disease in mid-life to older women to reduce morbidity and mortality associated with oestrogen decline.

FUNDING

Zoe Ltd.

Menopause Is Associated with an Altered Gut Microbiome and Estrobolome, with Implications for Adverse Cardiometabolic Risk in the Hispanic Community Health Study/Study of Latinos

Menopause is a pivotal period during which loss of ovarian hormones increases cardiometabolic risk and may also influence the gut microbiome. However, the menopause-microbiome relationship has not been examined in a large study, and its implications for cardiometabolic disease are unknown. In the Hispanic Community Health Study/Study of Latinos, a population with high burden of cardiometabolic risk factors, shotgun metagenomic sequencing was performed on stool from 2,300 participants (295 premenopausal women, 1,027 postmenopausal women, and 978 men), and serum metabolomics was available on a subset. Postmenopausal women trended toward lower gut microbiome diversity and altered overall composition compared to premenopausal women, while differing less from men, in models adjusted for age and other demographic/behavioral covariates. Differentially abundant taxa for post- versus premenopausal women included Bacteroides sp. strain Ga6A1, Prevotella marshii, and Sutterella wadsworthensis (enriched in postmenopause) and Escherichia coli-Shigella spp., Oscillibacter sp. strain KLE1745, Akkermansia muciniphila, Clostridium lactatifermentans, Parabacteroides johnsonii, and Veillonella seminalis (depleted in postmenopause); these taxa similarly differed between men and women. Postmenopausal women had higher abundance of the microbial sulfate transport system and decreased abundance of microbial β-glucuronidase; these functions correlated with serum progestin metabolites, suggesting involvement of postmenopausal gut microbes in sex hormone retention. In postmenopausal women, menopause-related microbiome alterations were associated with adverse cardiometabolic profiles. In summary, in a large U.S. Hispanic/Latino population, menopause is associated with a gut microbiome more similar to that of men, perhaps related to the common condition of a low estrogen/progesterone state. Future work should examine similarity of results in other racial/ethnic groups. IMPORTANCE The menopausal transition, marked by declining ovarian hormones, is recognized as a pivotal period of cardiometabolic risk. Gut microbiota metabolically interact with sex hormones, but large population studies associating menopause with the gut microbiome are lacking. Our results from a large study of Hispanic/Latino women and men suggest that the postmenopausal gut microbiome in women is slightly more similar to the gut microbiome in men and that menopause depletes specific gut pathogens and decreases the hormone-related metabolic potential of the gut microbiome. At the same time, gut microbes may participate in sex hormone reactivation and retention in postmenopausal women. Menopause-related gut microbiome changes were associated with adverse cardiometabolic risk in postmenopausal women, indicating that the gut microbiome contributes to changes in cardiometabolic health during menopause.

The relationship between night shift work and breast cancer incidence: A systematic review and meta-analysis of observational studies

The purpose of this study was to investigate the relationship between night shift work and breast cancer (BC) incidence. A search was performed in PubMed, EBSCO, Web of Science, and Cochrane Library databases before June 2021. The exposure factor of this study is night shift work, the primary outcome is the risk of BC. A total of 33 observational studies composed of 4,331,782 participants were included. Night shift work increases the risk of BC in the female population (hazard ratio [HR] = 1.20, 95% confidence interval [Cl] = 1.10–1.31, p < 0.001), especially receptor-positive BC, including estrogen receptor (ER)+ BC (HR = 1.35, p < 0.001), progesterone receptor (PR)+ BC (HR = 1.30, p = 0.003), and human epidermal growth factor receptor 2 (HER2)+ BC (HR = 1.42, p < 0.001), but has no effect on HER2− BC (HR = 1.10, p = 0.515) and ER−/PR− BC (HR = 0.98, p = 0.827). The risk of BC was positively correlated with night shift working duration, frequency, and cumulative times. For women who start night work before menopause, night work will increase the incidence of BC (HR = 1.17, p = 0.020), but for women who start night work after menopause, night work does not affect BC (HR = 1.04, p = 0.293). Night work can increase the incidence of BC in the female population. The effect of long working hours, frequency, and the cumulative number of night shifts on BC is influenced by menopausal status.

Pilot Trial of Vitamin D3 and Calcifediol in Healthy Vitamin D Deficient Adults: Does It Change the Fecal Microbiome?

CONTEXT

Experimental studies suggest that vitamin D receptor signaling may benefit the gut microbiome. In humans, whether vitamin D supplementation directly alters the gut microbiome is not well studied.

OBJECTIVE

To determine whether correcting vitamin D deficiency with cholecalciferol (vitamin D3, D3) or calcifediol (25-hydroxyvitamin D3, 25(OH)D3) changes gut microbiome composition.

METHODS

18 adults with vitamin D deficiency (25-hydroxyvitamin D [25(OH)D] <20 ng/mL) received 60 µg/day of D3 or 20 µg/day of 25(OH)D3 for 8 weeks. Changes in serum 25(OH)D, 1,25-diydroxyvitamin D (1,25(OH)2D), and 24,25-dihydroxyvitamin D (24,25(OH)2D) were assessed. We characterized composition of the fecal microbiota using 16S rRNA gene sequencing, and examined changes in α-diversity (Chao 1, Faith's Phylogenetic Diversity, Shannon Index), β-diversity (DEICODE), and genus-level abundances (DESeq2).

RESULTS

Vitamin D3 and 25(OH)D3 groups were similar. After 8 weeks of vitamin D3, mean 25(OH)D and 24,25(OH)2D increased significantly, but 1,25(OH)2D did not (25(OH)D: 17.8-30.1 ng/mL, P = .002; 24,25(OH)2D: 1.1 to 2.7 ng/mL, P =0.003; 1,25(OH)2D: 49.5-53.0 pg/mL, P = .9). After 8 weeks of 25(OH)D3, mean 25(OH)D, 24,25(OH)2D, and 1,25(OH)2D increased significantly (25(OH)D: 16.7-50.6 ng/mL, P < .0001; 24,25(OH)2D: 1.3-6.2 ng/mL, P = .0001; 1,25(OH)2D: 56.5-74.2 pg/mL, P = .05). Fecal microbial α-diversity and β-diversity did not change with D3 or 25D3 supplementation. Mean relative abundance of Firmicutes increased and mean relative abundance of Bacterioidetes decreased from baseline to 4 weeks, but returned to baseline by study completion. DESeq2 analysis did not confirm any statistically significant taxonomic changes.

CONCLUSION

In a small sample of healthy adults with vitamin D deficiency, restoration of vitamin D sufficiency with vitamin D3 or 25(OH)D3 did not lead to lasting changes in the fecal microbiota.

Weight, Shape, and Body Composition Changes at Menopause

Obesity and overweight are associated with increased risks of cardiovascular and metabolic disease and overall poor health outcomes. Menopause is associated with significant changes in body composition and the accumulation of peri-abdominal or visceral fat. Changes in energy expenditure and spontaneous activity have been noted. These mid-life changes can add further to the burden of obesity and its associated risks. An understanding of the role of estrogen, gonadotrophins, gut hormones, sleep deprivation and the microbiome is still rudimentary, but research will ultimately provide further targets for more effective management. This narrative review will explore the pathogenesis of body composition changes at menopause, the impact on health outcomes and therapeutic and management options.

Modulation of the Gut Microbiota Structure with Probiotics and Isoflavone Alleviates Metabolic Disorder in Ovariectomized Mice

The decrease in ovarian hormone secretion that occurs during menopause results in an increase in body weight and adipose tissue mass. Probiotics and soy isoflavones (SIFs) could affect the gut microbiota and exert anti-obesity effects. The objective of this study was to investigate the effects of probiotics and a diet containing SIF (SIF diet) on ovariectomized mice with menopausal obesity, including the gut microbiome. The results demonstrate that Bifidobacterium longum 15M1 can reverse menopausal obesity, whilst the combination of Lactobacillus plantarum 30M5 and a SIF diet was more effective in alleviating menopausal lipid metabolism disorder than either components alone. Probiotics and SIFs play different anti-obesity roles in menopausal mice. Furthermore, 30M5 alters the metabolites of the gut microbiota that increase the circulating estrogen level, upregulates the expression of estrogen receptor α in abdominal adipose tissue and improves the production of short-chain fatty acids (SCFAs). A SIF diet can significantly alter the structure of the fecal bacterial community and enrich the pathways related to SCFAs production. Moreover, 30M5 and a SIF diet acted synergistically to effectively resolve abnormal serum lipid levels in ovariectomized mice, and these effects appear to be associated with regulation of the diversity and structure of the intestinal microbiota to enhance SCFAs production and promote estrogen circulation.