The menopause-related gut microbiome: associations with metabolomics, inflammatory protein markers, and cardiometabolic health in women with HIV

OBJECTIVE

This study aimed to identify menopause-related gut microbial features, as well as their related metabolites and inflammatory protein markers, and link with cardiometabolic risk factors in women with and without HIV.

METHODS

In the Women's Interagency HIV Study, we performed shotgun metagenomic sequencing on 696 stool samples from 446 participants (67% women with HIV), and quantified plasma metabolomics and serum proteomics in a subset (~86%). We examined the associations of menopause (postmenopausal vs premenopausal) with gut microbial features in a cross-sectional repeated-measures design and further evaluated those features in relation to metabolites, proteins, and cardiometabolic risk factors.

RESULTS

Different overall gut microbial composition was observed by menopausal status in women with HIV only. We identified a range of gut microbial features that differed between postmenopausal and premenopausal women with HIV (but none in women without HIV), including abundance of 32 species and functional potentials involving 24 enzymatic reactions and lower β-glucuronidase bacterial gene ortholog. Specifically, highly abundant species Faecalibacterium prausnitzii , Bacteroides species CAG:98 , and Bifidobacterium adolescentis were depleted in postmenopausal versus premenopausal women with HIV. Menopause-depleted species (mainly Clostridia ) in women with HIV were positively associated with several glycerophospholipids, while negatively associated with imidazolepropionic acid and fibroblast growth factor 21. Mediation analysis suggested that menopause may decrease plasma phosphatidylcholine plasmalogen C36:1 and C36:2 levels via reducing abundance of species F. prausnitzii and Acetanaerobacterium elongatum in women with HIV. Furthermore, waist-to-hip ratio was associated with menopause-related microbes, metabolites, and fibroblast growth factor 21 in women with HIV.

CONCLUSIONS

Menopause was associated with a differential gut microbiome in women with HIV, related to metabolite and protein profiles that potentially contribute to elevated cardiometabolic risk.

Open Chromatin Profiling in Adipose Tissue Marks Genomic Regions with Functional Roles in Cardiometabolic Traits

Identifying the regulatory mechanisms of genome-wide association study (GWAS) loci affecting adipose tissue has been restricted due to limited characterization of adipose transcriptional regulatory elements. We profiled chromatin accessibility in three frozen human subcutaneous adipose tissue needle biopsies and preadipocytes and adipocytes from the Simpson Golabi-Behmel Syndrome (SGBS) cell strain using an assay for transposase-accessible chromatin (ATAC-seq). We identified 68,571 representative accessible chromatin regions (peaks) across adipose tissue samples (FDR < 5%). GWAS loci for eight cardiometabolic traits were enriched in these peaks (P < 0.005), with the strongest enrichment for waist-hip ratio. Of 110 recently described cardiometabolic GWAS loci colocalized with adipose tissue eQTLs, 59 loci had one or more variants overlapping an adipose tissue peak. Annotated variants at the SNX10 waist-hip ratio locus and the ATP2A1-SH2B1 body mass index locus showed allelic differences in regulatory assays. These adipose tissue accessible chromatin regions elucidate genetic variants that may alter adipose tissue function to impact cardiometabolic traits.

Association of circulating branched-chain amino acids with cardiometabolic traits differs between adults and the oldest-old

Branched-chain amino acids (BCAAs) are promising for their potential anti-aging effects. However, findings in adults suggest that circulating BCAAs are associated with cardiometabolic risk. Moreover, little information is available about how BCAAs influence clustered cardiometabolic traits in the oldest-old (>85 years), which are the fastest-growing segment of the population in developed countries. Here, we applied a targeted metabolomics approach to measure serum BCAAs in Chinese participants (aged 21-110 years) based on a longevity cohort. The differences of quantitative and dichotomous cardiometabolic traits were compared across BCAAs tertiles. A generalized additive model (GAM) was used to explore the dose-response relationship between BCAAs and the risk of metabolic syndrome (MetS). Overall, BCAAs were correlated with most of the examined cardiometabolic traits. The odds ratios for MetS across the increasing BCAA tertiles were 3.22 (1.70 - 6.12) and 5.27 (2.88 - 9.94, referenced to tertile 1) after adjusting for age and gender (P_trend < 0.001). The association still existed after further controlling for lifestyle factors and inflammation factors. However, the correlations between circulating BCAAs and quantitative traits were weakened in the oldest-old, except for lipids, the levels of which were distinctly different from those in adults. The stratified analysis also suggested that the risky BCAAs-MetS association was more pronounced in adults than in the oldest-old. Moreover, generalized additive model (GAM)-based curve-fitting suggested that only when BCAAs exceeded a threshold (approximately 450 μmol/L) was the BCAAs-MetS association significant. The relationship might be aging-dependent and was more pronounced in adults than in the oldest-old.