Biology subjects

Bigonne, H.

Publications and source records attributed to Bigonne, H..

3 recordsLinked to original sources

bioRxiv2026

Chemical probes reveal individualized gut microbiome biotransformation capacity and the impacts of ex vivo fermentation conditions

The gut microbiome transforms endogenous and exogenous chemicals, contributing to bioactivation or detoxification via the formation of metabolites with altered bioactivity. Most high content microbiome assays infer function from genetic composition rather than direct assessment of biotransformation activity, and it remains difficult to predict functional consequences of environmental factors and experimental variation. Therefore, we developed an anaerobic fecal fermentation workflow that couples targeted LC-MS/MS quantification of dynamic profiles of 20 chemical probes with untargeted metabolomics to profile human microbiome biotransformation capacity and used it to assess the impact of experimental conditions on biotransformation profiles. Across five donors and 240 fermentations, inoculum density and growth medium composition strongly influenced probe transformation rates, whereas the biotransformation capacities of fecal slurries frozen at -80{degrees}C did not differ from fresh fecal samples. Individual donors could be uniquely stratified on the basis of biotransformation profile data in a way that was not recapitulated by 16S rRNA taxonomic structure or predicted functional pathways. Finally, expected biotransformation products and metabolic trends could be confirmed with untargeted metabolomics characterization. This scalable platform directly profiles gut microbial biotransformation activity, supporting wider applications of standardized microbiome functional phenotyping in humans and quantitative models of microbiome-competent biokinetics assessment in pharmacology and toxicology.

microbiology↗

bioRxiv2025

Chemical activity profiling reveals how exposure to drugs or dietary compounds alters gut microbial biotransformation capacity

The gut microbiome catalyzes biotransformation reactions that influence intestinal absorption as a basis of microbiome-host interactions. A better understanding of microbiota biotransformation capacity, and its alteration in dysregulated states, would enable the prediction of individual responses to drugs and toxins and improve safety assessment. Here, we profiled chemical activities in rat gut microbiota ex vivo, and quantified biotransformation capacity changes induced by oral exposure to eight drugs and dietary compounds: tobramycin, colistin, acesulfame potassium, saccharin, bovine serum albumin (BSA), meropenem, doripenem, and daidzein. We implemented an approach involving inoculation with metabolic probes during microbiota fermentations and measured their degradation. In most exposure groups, we observed no alteration of microbiota biotransformation capacity, however, we detected significant alterations in biotransformation rates after exposure to meropenem, doripenem and tobramycin. Interestingly, common patterns of biotransformation capacity were observed in the gut microbiomes from rats exposed to carbapenems and partially shared in microbiomes exposed to tobramycin. These results aligned well with prior metagenomic and metabolomic findings. Further, correlations between microbial taxa and reaction rates were assessed to establish a link between specific bacteria and probe degradation. This functionally relevant strategy revealed alterations of microbiota biotransformation capacity, as induced by in vivo exposures.

microbiology↗

bioRxiv2024

Human internal exposures of bisphenol A and six data-poor analogues predicted by physiologically based kinetic models with multimodal parameterization

BackgroundBisphenols (BP) AF, B, E, F, M, and S have been introduced as substitutes for bisphenol A (BPA) and are increasingly used in consumer products. Despite widespread human exposure and potential adverse health outcomes related to BPF, BPB, BPS, and BPAF, their physiological disposition in humans is poorly characterized, which hinders assessment of associated risks. ObjectivesOur goal was to simulate the kinetic behavior of prevalent bisphenol analogs in organs of toxicological interest. To enable predictions of physiologically relevant internal concentrations of a family of structurally similar compounds with limited available human data, we aim to establish a reproducible framework using multimodal parameterization methods. MethodsHerein we developed physiologically based kinetic (PBK) models, following oral exposure. Their parametrization was primarily based on structural, physiological and experimental values, as well as quantitative structure-activity relationship (QSAR) predictions. Outputs were evaluated against available biomonitoring data for BPA and BPS. Critical parameters were identified by sensitivity analysis and iteratively re-sampled in Monte Carlo (MC) simulations to quantify uncertainties. ResultsAmong human models parametrized for males and females of different ages, we predicted that bisphenols reached the highest concentrations in 5-year-old males. Environmentally relevant exposure levels resulted in maximum concentrations in the blood and testes for BPS, and in the thyroid for BPM. After 96 hours, steady-state concentrations were not yet reached in the breasts for BPA, BPAF, BPB, BPE, BPF and BPM. ConclusionsThe data from this study suggest significant variability in internal concentrations for identical exposures to different bisphenols analogs that further depend on age, sex and organ. This diversity in toxicokinetic behavior should be considered for health risk assessment of these substitutes.

pharmacology and toxicology↗