Biology subjects

Vargas Robles, D.

Publications and source records attributed to Vargas Robles, D..

3 recordsLinked to original sources

bioRxiv2026

Environmental Fungi Modulate the Vaginal Mycobiome and Cervical Disease Progression in Hispanic Women

The vaginal mycobiome, though a minor component of the cervicovaginal ecosystem, plays a crucial role in reproductive health and disease. However, its composition and interactions with bacterial communities remain poorly understood, particularly among Hispanic women, who experience disproportionately high rates of Human papillomavirus (HPV) infection and cervical cancer. We characterized the vaginal mycobiota across reproductive stages and examined its associations with cervical disease, HPV status, and bacterial community state types (CSTs) in 86 Hispanic participants from Puerto Rico using ITS1 amplicon sequencing. Amplicon sequence variants were inferred with QIIME2/DADA2 and taxonomically classified using the UNITE database, with diversity and discriminant taxa analyses applied to explore clinical and microbial associations. We detected 173 fungal Species Hypotheses, dominated by Candida albicans, Agaricomycetes sp., Scopuloides dimorpha, and Hortaea werneckii. While fungal composition did not differ significantly by reproductive stage, non-pregnant individuals exhibited greater inter-individual variability. Alpha diversity was reduced in high-grade squamous intraepithelial lesions compared with low-grade or normal cytology, and Candida parapsilosis prevalence was elevated in low-grade lesions. CST III, characterized by Lactobacillus iners dominance, showed greater dispersion variance than other CSTs. Collectively, these findings reveal a diverse vaginal mycobiome with stage- and disease-specific features, and a notable contribution of environmental fungi that may influence cervical pathogenesis. This work provides foundational insight into cervicovaginal fungal ecology in a high-risk Hispanic population and highlights the importance of integrating bacteriome-mycobiome analyses in womens health research.

microbiology↗

bioRxiv2024

Association of diet and inflammation with the vaginal microbiota of pregnant individuals with or without IBD

Background and aimsVaginal dysbiosis has been associated with adverse pregnancy outcomes. Here, we characterized the vaginal microbiota of pregnant individuals with inflammatory bowel disease (IBD) and investigated whether gut or vaginal inflammation and diet influence the vaginal microbiota diversity of these individuals. Study DesignWe recruited 48 individuals in their third trimester of pregnancy (IBD=23 and HC=18). We characterized the vaginal microbiota by 16S rRNA sequencing and the gut microbiota by shotgun sequencing. We measured fecal calprotectin in stool and pro-inflammatory cytokines in vaginal fluids. We determine dietary quality using validated 24-hour dietary recalls. ResultsPregnant individuals with IBD exhibit higher levels of fecal calprotectin and increased expression of Th17 pro-inflammatory cytokines (i.e., IL-6, IL-8, IL-17) in the vaginal mucosa compared to healthy pregnant individuals. High fecal calprotectin correlated with high vaginal microbiota diversity. Also, IL-4 (reduced in IBD) was associated with vaginal microbial composition. Regardless of IBD status, pregnant individuals with healthier diets and particularly optimal servings of vegetables and sugars exhibited a vaginal microbiota dominated by Lactobacillus crispatus, a species associated with a lower risk of preterm birth and bacterial vaginosis. ConclusionBesides gut inflammation, pregnant individuals with IBD also exhibit a Th17 immune tone in the vaginal mucosa. The vaginal microbiota diversity or composition, particularly high in the beneficial L. crispatus, is positively associated with healthier diets, regardless of IBD status. Why was the study conducted?An altered vaginal microbiota has been implicated in preterm birth. There is no research on the vaginal microbiome and the factors that influence it in pregnant individuals with Inflammatory Bowel Disease (IBD) at a higher risk of preterm delivery. Key findingsPregnant individuals with IBD exhibit a comparable vaginal microbiome to healthy pregnant individuals. However, pregnant individuals with IBD present a vaginal immune profile characterized by increased levels of Th17 pro-inflammatory cytokines. High dietary quality, and optimal consumption of vegetables and added sugars were associated with vaginal dominance by the beneficial L. crispatus. What does this add to what is known?Our results indicate that the vaginal immune environment and not the microbiome might explain poor pregnancy outcomes for individuals with IBD. Moreover, our study supports the importance of diet to favor L. crispatus, a bacterium associated with a lower risk of preterm birth.

microbiology↗

bioRxiv2023

The cervical microbiota of Hispanics living in Puerto Rico is highly volatile and dominated by L. iners regardless of HPV status

IntroductionThe cervicovaginal microbiota is influenced by host physiology, immunology, lifestyle, and ethnicity. We hypothesized that there would be differences in the cervicovaginal microbiota among pregnant, non-pregnant and menopausal women living in Puerto Rico with and without Human Papillomavirus (HPV) infection and cervical cancer. We specifically wanted to determine if the microbiota associated with variation in cervical cytology. A total of 294 women comprised of reproductive-age non-pregnant (N=196), pregnant (N=37), and menopausal (N=61) women were enrolled. The cervicovaginal bacteria was characterized by 16S rRNA amplicon sequencing, the HPV were genotyped with SPF10-LiPA, and cervical cytology was quantified. High-risk HPV (HR-HPV, 67.3%) was prevalent, including genotypes not covered by the 9vt HPV vaccine. Cervical lesions (34%) were also common. The cervical microbiota was dominated by Lactobacillus iners. Pregnant women in the 2nd and 3rd trimesters had decreased diversity and a decreased abundance of microbes associated with bacterial vaginosis. Women in menopause had greater alpha diversity, a greater proportion of facultative and strictly anaerobic bacteria, and higher cervicovaginal pH than pre-menopausal women. Cervical lesions were associated with greater alpha diversity. However, no significant associations between the microbiota and HPV infection (HR or LR-HPV types) were found. The cervicovaginal microbiota women living in Puerto Rican were either dominated by L. iners or diverse microbial communities regardless of a womans physiological stage. We postulate that the microbiota and the high prevalence of HR-HPV, increase the risk of cervical lesions of women living in Puerto Rico.

microbiology↗