Biology subjects

Chatman, C. C.

Publications and source records attributed to Chatman, C. C..

3 recordsLinked to original sources

bioRxiv2025

Lifetime exposure to known and emerging groundwater contaminants significantly alters poultry microbiome and metabolome

The exposome encompasses all lifetime environmental exposures affecting health. Its complexity and high data dimensionality make it challenging to link specific exposure combinations to adverse health outcomes. Establishing relevant exposome criteria is key to addressing current knowledge gaps. This study evaluated contaminant levels in Wisconsin groundwater and their effects on host health. We focused on three co-occurring chemicals that were detected at concentrations exceeding groundwater standards, nitrate, atrazine and imidacloprid, and the emerging contaminant, microplastics. In this study, broilers were exposed to a low dose chemical mixture (35,000 ppb nitrate + 1.7 ppb atrazine + 0.58 ppb imidacloprid) and high dose chemical mixture (100,000 ppb nitrate + 3,000 ppb atrazine + 3,000 ppb imidacloprid) or polyethylene microplastics (PE MPs) for 49 days. We observed that both ternary mixtures and PE fiber MPs significantly altered the cecal microbiomes as determined by the enrichment of genera, Fournierella, Ruminococcus and an unclassified genus in the family Coriobacteriaceae. In addition, +PE fiber presence dysregulated metabolic pathways associated with bile acid biosynthesis and lipid metabolism. Similarly, perturbations to cecal microbial activity for both ternary chemical mixtures were confirmed via modulation of six metabolites including methylisopelletierine which had a higher total ion intensity than the control group. Interestingly, there were no detectable pathological effects to either the +PE fiber or ternary mixture treatment groups. Overall, the data presented here demonstrates that low doses of environmental contaminants are sufficient to dysregulate cecal taxonomic composition and microbial activity without inducing detectable pathological effects. ImportanceWe found that exposure to mixtures of environmental toxins caused gut dysbiosis observed by changes to the chicken cecal microbiome and metabolome. This highlights the importance of conducting such studies with environmentally relevant mixtures of contaminants at detected concentrations to understand the actual risks associated with exposures like drinking contaminated groundwater over a long period of time. Our findings demonstrate that gut microbial metabolites, now known to be key regulators and signaling molecules in a wide range of host health issues, are the source of the negative health outcomes; superseding cell death or pathological damage that are caused by acute exposures. These changes have implications for predicting negative long-term chronic health outcomes.

systems biology↗

bioRxiv2025

Acute exposure to groundwater contaminants mixture of nitrate, atrazine and imidacloprid impacts growth kinetics of poultry cecal microbiomes and significantly decreases Caco-2 cell viability

Atmospheric deposition, and agricultural runoff or erosion events have substantially contributed to groundwater pollution throughout the USA. This can become troublesome in states like Wisconsin where 68% of the population rely on groundwater for their drinking water source. As such, exposome research must account for the complexity and frequency of environmental exposures. This study aimed to elucidate chemical-biological interactions and adverse outcome pathways associated with an environmentally relevant mixture of agricultural chemicals detected in Wisconsin groundwater via in vitro and in silico methodologies. Using in vitro models, we determined that a ternary mixture of environmentally relevant concentrations of nitrate, atrazine and imidacloprid resulted in an overt decline in growth rate to the poultry cecal microbiome compared to each chemical singularly. Further, there was a decrease in Caco-2 cell viability in various two-chemical combinations. In silico methods analyzed contaminants detected in Wisconsin groundwater wells from across the state and prioritized two groundwater wells as potential for health concerns. Prioritized chemicals in these groundwater wells were linked to nine gene targets and several adverse outcome pathways. In all, the results demonstrated that there is chemical-biological interaction between these model organisms agricultural and chemical mixtures at real world exposure concentrations. HighlightsO_LIin silico methods were able to predict potential adverse effects for communities utilizing these groundwater wells C_LIO_LI8 out of 9 chemicals prioritized with in silico tools were herbicides C_LIO_LIA ternary mixture of nitrate, imidacloprid and atrazine resulted in a decline in growth rate for poultry cecal microbiome C_LIO_LICaco-2 cells significantly impacted by two-chemical combinations but not ternary mixtures C_LI

pharmacology and toxicology↗

bioRxiv2023

Co-exposure to Polyethylene Fiber and Salmonella enterica Typhimurium Alters Microbiome and Metabolome of in vitro Chicken Cecal Mesocosms

Humans and animals encounter a summation of exposures during their lifetime (the exposome). In recent years, the scope of the exposome has begun to include microplastics. Microplastics (MPs) have increasingly been found in locations where there could be an interaction with Salmonella enterica Typhimurium, one of the commonly isolated serovars from processed chicken. In this study, the microbiota response to a 24-hour co-exposure to Salmonella enterica Typhimurium and/or low-density polyethylene (PE) microplastics in an in vitro broiler cecal model was determined using 16S rRNA amplicon sequencing (Illumina) and untargeted metabolomics. Community sequencing results indicated that PE fiber with and without S. Typhimurium yielded a lower Firmicutes/Bacteroides ratio compared to other treatment groups, which is associated with poor gut health, and overall had greater changes to the cecal microbial community composition. However, changes in the total metabolome were primarily driven by the presence of S. Typhimurium. Additionally, the co-exposure to PE Fiber and S. Typhimurium caused greater cecal microbial community and metabolome changes than either exposure alone. Our results indicate that polymer shape is an important factor in effects resulting from exposure. It also demonstrates that microplastic-pathogen interactions cause metabolic alterations to the chicken cecal microbiome in an in vitro chicken cecal model. IMPORTANCEResearching the exposome, a summation of exposure of ones lifespan, will aid in determining the environmental factors that contribute to disease states. There is an emerging concern that microplastic-pathogen interactions in the gastrointestinal tract of broiler chickens may lead to an increase in Salmonella infection across flocks and eventually increased incidence of human salmonellosis cases. In this research article, we elucidated the effects of co-exposure to polyethylene microplastics and Salmonella enterica serovar Typhimurium on the ceca microbial community. Salmonella presence caused strong shifts in the cecal metabolome but not the microbiome. The inverse was true for polyethylene fiber. Polyethylene powder had almost no effect. The co-exposure had worse effects than either alone. This demonstrates that exposure effects to the gut microbial community are contaminant specific. When combined, the interactions between exposures exacerbate changes to the gut environment. The results herein support current Salmonella mitigation efforts and understanding microplastics-pathogen interactions.

systems biology↗