Biology subjects

Condori-Catachura, S.

Publications and source records attributed to Condori-Catachura, S..

3 recordsLinked to original sources

bioRxiv2025

Vitamin B2 Production by Vaginal Lactobacilli Promotes Symbiosis

The human vaginal microbiome, particularly with lactobacilli as the main inhabitants, plays a key role in maintaining womens health. While lactic acid-mediated pathogen exclusion is well known, broader metabolic functions of vaginal lactobacilli remain underexplored. In this study, we analyzed the vaginal microbiome and metabolome of 258 healthy women from the Isala program. Using targeted metabolomics analysis, we detected a high prevalence with strong interpersonal differences of most B-vitamins, their precursors, and vitamin A in the vaginal microenvironment. Riboflavin (B2) and biotin (B7) showed strong associations with Lactobacillus crispatus and Limosilactobacillus sp. Comparative genomics, phenotypic assays, and in vivo metatranscriptomic data (VIRGO2) collectively confirmed riboflavin biosynthesis by these taxa. Using a riboflavin overproducing Lim. reuteri as a functional model, we showed that microbially derived riboflavin and its pathway intermediates are transported across the vaginal epithelium and modulate host redox balance, cytokine production, and activation of mucosal-associated invariant T (MAIT) cells via induction of MR1 (Major histocompatibility complex, class I-related protein receptor), revealing a potential immunometabolic interface between the vaginal microbiota and its host.

microbiology↗

bioRxiv2025

First-void urine and cervicovaginal brushes as sampling devices for vaginal microbiome studies: a proof-of-concept study

This proof-of-concept study compares first-void urine (FVU) and cervicovaginal brushes to vaginal swabs for microbiome profiling in ten women. FVU and brushes provided comparable results in most cases, though storage conditions influenced microbial composition, especially for FVU. Despite limitations in sample size and diversity in participants, findings support these methods potential for self-sampling in womens health research, emphasizing the need for optimized techniques to improve vaginal microbiome profiling.

microbiology↗

bioRxiv2024

Lacticaseibacillus rhamnosus GG in a chewable colonizes the nose and facilitates local immune benefits in allergic rhinoconjunctivitis patients

Current treatments fall short in managing allergic rhinitis (AR), emphasizing the need for additional strategies. Beneficial bacteria application shows promise in AR, however most studies focus on oral probiotic administration without monitoring the applied strains in the upper respiratory tract (URT) and their local effects. In this randomized, double-blind, placebo-controlled trial, the probiotic Lacticaseibacillus rhamnosus GG was administered via chewable tablets in seasonal AR patients, randomized to probiotic (n=33) or placebo (n=31) groups. Per-protocol analysis of the URT microbiome, immune markers and AR symptoms was performed. L. rhamnosus GG trafficked from chewables to the oropharynx (77%, p=0.02) and nasopharynx (41%, p<0.0001). Control of self-reported AR symptoms via validated questionnaires under grass pollen exposure was observed after two weeks of probiotic administration and not upon placebo. A local decrease in salivary interleukin-4 (p < 0.05) and nasal IL-13 (p < 0.0001) was observed in the probiotic group. These data indicate that L. rhamnosus GG chewables can target the URT and exert local effects on key allergy cytokines after temporal probiotic engraftment. ImportanceAllergic rhinitis (AR) or hay fever is a highly prevalent condition, impacting nearly half the population in some countries. Supplementation of beneficial bacteria or probiotics has gained increasing attention in AR, and a key innovative way to do this is direct administration to the upper airways. Our study shows for the first time that the model probiotic strain Lacticaseibacillus rhamnosus GG can traffic to the nose in AR patients when administered via a slow-releasing chewable tablet. This trafficking is associated with local benefits in the airways, including on grass pollen-induced nasal symptoms and allergy-related cytokines.

microbiology↗