@article{patra_nunn_levent_chelikani_2025, title={Prebiotics pectin and resistant starch‐type 4 stimulate peptide <scp>YY</scp> and cholecystokinin to promote satiety, and improve gut microbiota composition}, url={https://doi.org/10.1096/fj.202403239R}, DOI={10.1096/fj.202403239R}, abstractNote={Dietary prebiotics pectin and resistant starch type-4 (RS-4) promote satiety and alter gut microbiota; however, the underlying neurohormonal mechanisms of satiety remain poorly understood. We determined the effects of pectin, RS-4, and their combination on energy balance and gut microbiota composition, and assessed whether the gut hormones peptide YY (PYY) and cholecystokinin (CCK) play a role in fiber-induced satiety. High-fat diet -induced obese male rats (n = 7-8/group) were fed either control, pectin, RS-4, or a combination of pectin and RS-4 diet. We found that pectin, RS-4, and their combination decreased food intake. Pectin alone, or combined with RS-4, shifted substrate utilization towards fat and reduced gains in weight and adiposity. Pectin alone or combined with RS-4 enhanced the expression and plasma concentrations of PYY and CCK. Importantly, systemic blockade of PYY-Y2 and CCK-1 receptors attenuated the hypophagic effects of pectin, and CCK-1 receptor blockade partly attenuated the hypophagia from RS-4. The prebiotics significantly altered fecal β-diversity metrics, suggestive of improvements in gut microbiota composition. Pectin and RS-4 alone, or in combination, were associated with increased relative abundance of phylum Bacteroidota, decreased Firmicutes, and increased concentrations of amino acids and biogenic amines in feces. Collectively, these findings suggest that dietary pectin and RS-4 improved energy balance and gut microbiota composition, and importantly, demonstrated that the satiety effects of these diets were mediated, in part, via enhanced endogenous PYY and CCK signaling.}, journal={The FASEB Journal}, author={Patra, Souvik and Nunn, Savana L. Everhart and Levent, Gizem and Chelikani, Prasanth K.}, year={2025}, month={Mar} }
 @article{thompson_nunn_sarkar_clayton_2023, title={Diagnostic Screening of Bovine Mastitis Using MALDI-TOF MS Direct-Spotting of Milk and Machine Learning}, url={https://doi.org/10.3390/vetsci10020101}, DOI={10.3390/vetsci10020101}, abstractNote={Novel strategies for diagnostic screening of animal and herd health are crucial to contain disease outbreaks, maintain animal health, and maximize production efficiency. Mastitis is an inflammation of the mammary gland in dairy cows, often resulting from infection from a microorganism. Mastitis outbreaks result in loss of production, degradation of milk quality, and the need to isolate and treat affected animals. In this work, we evaluate MALDI-TOF mass spectrometry as a diagnostic for the culture-less screening of mastitis state from raw milk samples collected from regional dairies. Since sample preparation requires only minutes per sample using microvolumes of reagents and no cell culture, the technique is promising for rapid sample turnaround and low-cost diagnosis. Machine learning algorithms have been used to detect patterns embedded within MALDI-TOF spectra using a training set of 226 raw milk samples. A separate scoring set of 100 raw milk samples has been used to assess the specificity (spc) and sensitivity (sens) of the approach. Of machine learning models tested, the gradient-boosted tree model gave global optimal results, with the Youden index of J = 0.7, sens = 0.89, and spc = 0.81 achieved for the given set of conditions. Random forest models also performed well, achieving J > 0.63, with sens = 0.83 and spc = 0.81. Naïve Bayes, generalized linear, fast large-margin, and deep learning models failed to produce diagnostic results that were as favorable. We conclude that MALDI-TOF MS combined with machine learning is an alternative diagnostic tool for detection of high somatic cell count (SCC) and subclinical mastitis in dairy herds.}, journal={Veterinary Sciences}, author={Thompson, Jonathan and Nunn, Savana L. Everhart and Sarkar, Sumon and Clayton, Beth}, year={2023}, month={Jan} }
 @article{kirchner_everhart_doring_smits_faircloth_duong_goulter_goodson_shelley_shumaker_et al._2022, title={Cross-Contamination to Surfaces in Consumer Kitchens with MS2 as a Tracer Organism in Ground Turkey Patties}, volume={85}, ISSN={0362-028X}, url={http://dx.doi.org/10.4315/JFP-22-060}, DOI={10.4315/JFP-22-060}, abstractNote={It is estimated that one in five cases of foodborne illnesses is acquired in the home. However, how pathogens move throughout a kitchen environment when consumers are preparing food is not well characterized. The purpose of this study was to determine the prevalence and degree of cross-contamination across a variety of kitchen surfaces during a consumer meal preparation event. Consumers (n = 371) prepared a meal consisting of turkey patties containing the bacteriophage MS2 as a tracer organism and a ready-to-eat lettuce salad. Half were shown a video on proper thermometer use before the trial. After meal preparation, environmental sampling and detection were performed to assess cross-contamination with MS2. For most surfaces, positivity did not exceed 20%, with the exception of spice containers, for which 48% of the samples showed evidence of MS2 cross-contamination. Spice containers also had the highest MS2 concentrations, at a mean exceeding 6 log viral genome equivalent copies per surface. The high level of MS2 on spice containers drove the significant differences between surfaces, suggesting the significance of spice containers as a vehicle for cross-contamination, despite the absence of previous reports to this effect. The thermometer safety intervention did not affect cross-contamination. The efficiency of MS2 transfer, when expressed as a percentage, was relatively low, ranging from an average of 0.002 to 0.07%. Quantitative risk assessment work using these data would aid in further understanding the significance of cross-contamination frequency and efficiency. Overall, these data will help create more targeted consumer messaging to better influence consumer cross-contamination behaviors.HIGHLIGHTSForty-eight percent of spice containers sampled showed evidence of MS2 cross-contamination.Spice containers had the highest MS2 concentrations across kitchen surfaces.Spice containers may be a key vehicle for cross-contamination.The thermometer safety intervention did not affect cross-contamination.The efficiency of MS2 transfer was relatively low, ranging from 0.002 to 0.07%.}, note={Published 2022 by the International Association for Food Protection. Not subject to U.S. Copyright.}, number={11}, journal={Journal of Food Protection}, publisher={Elsevier BV}, author={Kirchner, Margaret and Everhart, Savana and Doring, Lindsey and Smits, Caitlin and Faircloth, Jeremy and Duong, Minh and Goulter, Rebecca M. and Goodson, Lydia and Shelley, Lisa and Shumaker, Ellen Thomas and et al.}, year={2022}, month={Nov}, pages={1594–1603} }