Recent interest in the role of microbiota in health and disease has implicated gut microbiota dysbiosis in psychiatric disorders including major depressive disorder. Several antidepressant drugs that belong to the class of selective serotonin reuptake inhibitors have been found to display antimicrobial activities. In fact, one of the first antidepressants discovered serendipitously in the 1950s, the monoamine-oxidase inhibitor Iproniazid, was a drug used for the treatment of tuberculosis. In the current study we chronically treated DBA/2J mice for 2 weeks with paroxetine, a selective serotonin reuptake inhibitor, and collected fecal pellets as a proxy for the gut microbiota from the animals after 7 and 14 days. Behavioral testing with the forced swim test revealed significant differences between paroxetine- and vehicle-treated mice. Untargeted mass spectrometry and 16S rRNA profiling of fecal pellet extracts showed several primary and secondary bile acid level, and microbiota alpha diversity differences, respectively between paroxetine- and vehicle-treated mice, suggesting that microbiota functions are altered by the drug. In addition to their lipid absorbing activities bile acids have important signaling activities and have been associated with gastrointestinal diseases and colorectal cancer. Antidepressant drugs like paroxetine should therefore be used with caution to prevent undesirable side effects.

Here, we report the characterization of two Cupriavidus strains, NOV2-1 and OV2-1, isolated from an iron-oxide deposit in an underground tunnel of the Naica mine in Mexico. This unique biotope, characterized by its high temperature (≈50 °C) and the presence of heavy metals, is no longer available for sampling at this time. The genomes of NOV2-1 and OV2-1 comprised two replicons: a chromosome of 3.58 and 3.53 Mb, respectively, and a chromid of 2.1 Mb in both strains. No plasmids were found. The average nucleotide identity and the core genome phylogeny showed that NOV2-1 and OV2-1 belonged to the Cupriavidus gilardii species. NOV2-1 and OV2-1 grew up to 48 °C, with an optimal temperature of 42 °C. Discrete differences were observed between C. gilardii CCUG38401^T, NOV2-1, and OV2-1 in the biochemical tests. NOV2-1 and OV2-1 presented resistance to zinc, lead, copper, cadmium, nickel, and cobalt. Several complete and incomplete gene clusters related to the resistance to these heavy metals (ars, czc, cop 1, sil-cop 2, cup, mmf, and mer) were detected in the genome of these strains. Although further studies are needed to determine the origin and role of the detected gene clusters, it is suggested that the czc system may have been mobilized by horizontal gene transfer. This study expands the extreme biotopes where Cupriavidus strains can be retrieved.

The Cuatro Ciénegas Basin (CCB) in Coahuila, Mexico, a Ramsar Wetland, is characterized by a unique network of pozas renowned for microbial diversity. Among them, the Churince hydrological system epitomized a delicate balance of endemic species, stable water regimes, and complex microbial assemblages. Over the last five decades, however, the Churince underwent catastrophic ~ 99% water loss, driven by intensive agricultural extraction. This desiccation caused hydrological collapse and reshaped microbial physiology. Longitudinal records from 2007 to 2025, combining satellite imagery, piezometer data, and field observations, documented progressive declines beginning in 2011 and culminating in complete desiccation by 2019. To track microbial responses, we employed a cultivation-based approach distinguishing vegetative cells from dormant spores, quantified as heat-resistant CFU, enabling direct physiological assessment of metabolic activity versus dormancy. As water diminished, spore abundance increased relative to vegetative forms, revealing a shift toward dormancy as a survival strategy under extreme desiccation. Complementary mesocosm experiments showed that reduced diversity further enriched for spores, illustrating how loss of community complexity accelerated dormancy and erosion of active assemblages. Together, these results demonstrated that habitat loss triggered microbial community change, which we frame as a microbial extension of the ecological concept of community disassembly. By combining two decades of hydrological evidence with microbial physiology, this study fills a critical gap in understanding how wetland drying selects for microbial dormancy. These findings underscore the urgent need for sustainable agriculture and integrated water management to preserve biodiversity and ecosystem function in threatened wetlands worldwide.

Stratified benthic deposits offer crucial modern analogs for Precambrian biogeochemical dynamics, yet whether the vertical organization of deep sedimentary columns reflects depositional history, present-day geochemical conditions, or both remains poorly understood, particularly under extreme oligotrophy. Here, we present a depth-resolved exploratory survey of a continuous 34-cm sediment core partitioned into 11 discrete horizons (L1 to L11) from Poza Roja 2, an alkaline, sub-hypersaline pond in the Cuatro Ciénegas Basin, Mexico. Integrating physical stratigraphy, organic carbon and nutrient stoichiometry, and 16S rRNA gene metabarcoding, we evaluated down-core microbial community structure alongside acute phosphorus scarcity. Molar C:Po and N:Po ratios exceeded canonical Redfield proportions (106:16:1) in every layer, by up to 48.5-fold and 87.8-fold, respectively, both peaking in layer L4. Unconstrained ordination (PCoA) and hierarchical clustering grouped the layers into three compositional zones: upper (L2–L4), intermediate (L5–L6), and basal (L8–L11), with L1 and L7 occupying transitional positions. Archaea accounted for 31.0% of prokaryotic reads, ranging from 8.3% (L5) to 43.7% (L9), and were dominated by SM1-50 (Thermoplasmatota) and Halobacteriota. The phototrophic heliobacterium Heliorestis peaked in the intermediate zone (47.6% of bacterial reads in L6). Constrained Redundancy Analysis models lacked statistical significance (P ≥ 0.12), highlighting the exploratory nature of a single core (n = 11). This pilot characterization provides a baseline for understanding deep biogenic archives under severe nutrient limitation.

The Cuatro Ciénegas Basin (CCB) in Coahuila, Mexico, a Ramsar Wetland, is historically characterized by a unique network of pozas renowned for microbial diversity. Among them, the Churince hydrological system epitomized a delicate balance of endemic species, stable water regimes, and complex microbial assemblages. Over the last five decades, however, Churince underwent a catastrophic ∼99% water loss, primarily driven by intensive agricultural extraction. We showed that this desiccation not only caused hydrological collapse but also reshaped microbial physiology. Longitudinal records from 2007 to 2019, combining satellite imagery, piezometer data, and field observations, documented progressive declines beginning in 2011 and culminating in the complete desiccation of the Intermediate Lagoon by 2019. To track microbial responses, we employed a cultivation-based approach distinguishing vegetative cells from dormant spores, enabling direct physiological assessment of metabolic activity versus dormancy. As water diminished, spore abundance increased relative to vegetative forms, revealing a shift toward dormancy as a survival strategy under extreme desiccation. Complementary mesocosm experiments showed that reduced diversity further enriched for spores, illustrating how loss of community complexity accelerated dormancy and erosion of active assemblages. Together, these results demonstrated that habitat loss triggered microbial community change, which we frame as a microbial extension of the ecological concept of community disassembly. By combining two decades of hydrological evidence with microbial physiology, this study fills a critical gap in understanding how wetland drying selects for microbial dormancy. These findings underscore the urgent need for sustainable agriculture and integrated water management to preserve biodiversity and ecosystem function in threatened wetlands worldwide.