The effects of hormone replacement therapy on the microbiomes of postmenopausal women.

The sex steroid hormone estrogen plays a number of regulatory roles in female development. During menopause, estrogen synthesis in the ovaries decreases, which results in adverse physiological remodeling and increased risk of disease. Reduced bone density, changes in the community composition profiles of the gut and vaginal microbiome, mood swings and changes in the vaginal environment are to be expected during this time. To alleviate these changes, postmenopausal women can be prescribed hormone replacement therapy (HRT) through the use of exogenous estradiol, often in conjunction with progestin treatment, which re-induces estrogenic action throughout the body. The microbiome and estrogen have a bidirectional, regulatory relationship in the gut, while in the vaginal environment estrogen works indirectly on the microbiome through restoring the vaginal tissue environment that leads to microbial homeostasis. This review discusses what is known about how the gut and vaginal microbiomes of postmenopausal women are responding to HRT, and the potential future of microbe-based therapeutics for symptoms of menopause.

Insect exclusion limits variation in bacterial microbiomes of tomato flowers and fruit.

AIMS: The effect of insect exclusion via netting on bacterial microbiota associated with field-grown tomato fruit and flowers was evaluated. METHODS AND RESULTS: Amplicon-based bacterial community profiling from insect-exposed plants and plants wrapped in nylon mosquito netting was conducted on total DNA extracted from tomato flower and mature unripe fruit washes. The V1-V3 region of the 16S rRNA gene was sequenced using Illumina MiSeq and analysed using qiime ver. 1.8. The carposphere supported significantly more phylogenetic diversity (PD) compared to the anthosphere, as measured by operational taxonomic unit richness (P = 0·001) and Faith's PD (P = 0·004). Flowers and fruit hosted distinct bacterial community structures (R2 = 0·27, P = 0·001), with specific taxonomic differences in taxa that included the Xanthomonadaceae (higher in flowers), and the Pseudomonadaceae, Methylobacteriaceae and Rhizobiales (higher in fruit) (FDR-P < 0·05). Bacterial community profiles of netted plants were overall statistically similar to non-netted plants for both flowers and fruit (P > 0·10). However, less variation between samples was observed among flowers (~50% less, P = 0·004) and green fruit (~10% less, P = 0·038) collected from netted than non-netted plants. CONCLUSION: Insects may introduce or augment variability in bacterial diversity associated with tomato flowers and potentially green fruit surfaces. SIGNIFICANCE AND IMPACT OF THE STUDY: This work contributes to knowledge on microbiome dynamics of the tomato holobiont. Deciphering drivers of bacterial diversity and community structure of fruit crops could reveal processes important to agricultural management, such as competitive exclusion of pathogens and priming of plant defense mechanisms.

A comparison of iohexol and diatrizoate-meglumine in children undergoing cardiac catheterization.

Iohexol (Omnipaque) and meglumine and sodium diatrizoate (Renografin-76) were compared in a double-blind, randomized study for their efficacy, safety, and hemodynamic effects as angiographic contrast agents in children. Forty-four children were randomly allocated to receive either iohexol or diatrizoate as a component of their routine or emergency cardiovascular evaluation. Following age stratification, baseline physiologic parameters were not significantly different between patients receiving either iohexol or diatrizoate. After systemic ventricular injection, iohexol produced significantly less hemodynamic alteration in systemic systolic blood pressure, systemic ventricular end-diastolic pressure, and dP/dt. Less alteration in heart rate and significantly less effect on the QT interval were seen with iohexol. Image quality was comparable, although significantly more patient mobility was associated with diatrizoate-meglumine. This study shows that iohexol, a nonionic contrast medium, causes less hemodynamic disturbance than diatrizoate-meglumine in children. Therefore, its use to be preferred in these potentially high-risk patients.