Soluble E-cadherin: A marker of genital epithelial disruption

Impact of antimicrobials on penile HIV susceptibility and immunology in uncircumcised men: A randomized phase 1/2 clinical trial

Within the penile microbiome, bacteria associated with seroconversion, immunology, and cells (BASIC species) enhance HIV susceptibility in heterosexual uncircumcised men by inducing foreskin inflammation and HIV target cell recruitment. This phase 1/2 clinical trial randomizes HIV-uninfected Ugandan men (n = 125) to either oral tinidazole, topical metronidazole, topical clindamycin, or topical hydrogen peroxide to define impact on ex vivo foreskin HIV susceptibility, penile immunology, and BASIC species density. Antimicrobials are well tolerated, and 116 (93%) participants complete the protocol. Topical metronidazole and oral tinidazole reduce the inner foreskin tissue density of HIV-susceptible CD4+ T cells (predefined primary endpoint). Antimicrobials also have varying but substantial effects on reducing prepuce inflammation and BASIC species density, reducing density of foreskin T cell subsets, and increasing foreskin epithelial integrity. Immune alterations correlate strongly with changes in the abundance of BASIC species. Clinical interventions targeting the penile microbiota, particularly topical metronidazole, may reduce HIV susceptibility in uncircumcised men.

The vaginal microbiome and HIV transmission dynamics

PURPOSE OF REVIEW

Among women, having a nonoptimal, highly diverse vaginal microbiome dominated by bacteria other than optimal Lactobacillus species such as L. crispatus or L. jensenii predicts HIV transmission. Reducing HIV acquisition among women requires a better understanding of the mechanisms through which the vaginal microbiome impacts HIV transmission dynamics and how to more effectively treat and intervene. Technological advancements are improving the ability of researchers to fully characterize interacting host-bacteria mechanisms. Consequently, the purpose of this review was to summarize the most innovative research on the vaginal microbiome and its role in HIV transmission in the past year.

RECENT FINDINGS

Studies combining multiomics, experimental, and translational approaches highlight the associations of a nonoptimal microbiome with maladaptive alterations in immune cell functioning, vaginal metabolites, host cell transcription, mucosal immunity, and epithelial barrier integrity. While there are multiple mechanisms proposed to increase HIV acquisition risk, there are virtually zero acceptable and effective treatments to improve the vaginal microbiome and immunity.

SUMMARY

Women-centered solutions to modify the vaginal microbiome and bacterial metabolites should continue to be explored as a mechanism to reduce HIV acquisition.

Penile microbiome: decoding its impact on HIV risk

PURPOSE OF REVIEW

The penile microbiome has been linked to local inflammation and increased risk for sexually transmitted infections, including HIV. This review explores recent studies of this emerging area of HIV research.

RECENT FINDINGS

The male urogenital tract supports multiple distinct niches, where their associated microbiome are shaped by abiotic (e.g., oxygen, moisture) and biotic (e.g., host immunity) environmental factors and host behaviors, particularly sexual activity. In addition, male circumcision is a significant drivers of male genital microbiome in both children and adults. Recent sexual partner studies provide new insight into the exchange of genital bacteria and concurrent local immune changes that may impact HIV risk.

SUMMARY

The male genital microbiome is shaped by the local microenvironment and host behaviors including sexual activity. Improving our understanding of the connection between the male genital microbiome, local inflammation, and HIV susceptibility, as well as how pro-inflammatory genital bacteria are transmitted between sexual partners may inform new strategies to prevent HIV transmission.

Recent progress in Porphyra haitanensis polysaccharides: Extraction, purification, structural insights, and their impact on gastrointestinal health and oxidative stress management

Porphyra haitanensis, a red seaweed species, represents a bountiful and sustainable marine resource. P. haitanensis polysaccharide (PHP), has garnered considerable attention for its numerous health benefits. However, the comprehensive utilization of PHP on an industrial scale has been limited by the lack of comprehensive information. In this review, we endeavor to discuss and summarize recent advancements in PHP extraction, purification, and characterization. We emphasize the multifaceted mechanisms through which PHP promotes gastrointestinal health. Furthermore, we present a summary of compelling evidence supporting PHP's protective role against oxidative stress. This includes its demonstrated potent antioxidant properties, its ability to neutralize free radicals, and its capacity to enhance the activity of antioxidant enzymes. The information presented here also lays the theoretical groundwork for future research into the structural and functional aspects of PHP, as well as its potential applications in functional foods.

Insertive vaginal sex is associated with altered penile immunology and enrichment of Gardnerella vaginalis in uncircumcised Ugandan men

PROBLEM

HIV susceptibility is linked to the penile immune milieu (particularly IL-8 levels) and microbiome. The effects of insertive vaginal sex itself on penile immunology and microbiota are not well described.

METHOD OF STUDY

We compared the immune milieu and microbiology of the coronal sulcus (CS) and distal urethra in 47 uncircumcised Ugandan men reporting ever (n = 42) or never (n = 5) having had vaginal intercourse. Soluble immune factors were assayed by multiplex ELISA, and penile bacteria abundance by 16S rRNA qPCR and sequencing. Co-primary endpoints were penile levels of IL-8 and soluble E-cadherin.

RESULTS

Independent of classical STIs, men reporting prior vaginal sex demonstrated elevated IL-8 levels in both the coronal sulcus (1.78 vs. 0.81 log10 pg/mL, p = .021) and urethra (2.93 vs. 2.30 log10 pg/mL; p = .003), with a strong inverse relationship between urethral IL-8 levels and the time from last vaginal sex (r = -0.436; p = .004). Vaginal sex was also associated with elevated penile IL-1α/β and soluble E-cadherin (sEcad), a marker of epithelial disruption. Gardnerella vaginalis (Gv) was only present in the penile microbiome of men reporting prior vaginal sex, and urethral Gv absolute abundance was strongly associated with urethral inflammation (r = 0.556; p < .001); corynebacteria were enriched in the CS of men reporting no prior vaginal sex and were associated with reduced CS inflammation.

CONCLUSIONS

Sexual intercourse was associated with sustained changes in penile immunology, potentially mediated through microbial alterations, in particular the urethral abundance of G. vaginalis. Future studies should further characterize the effects of sexual debut on penile bacteria and immunology.