top of page
Karst Laboratory
University of Florida, Dept. of Molecular Genetics and Microbiology
Publications
Representative publications from the Karst Lab
Phophi L, Wilt HM, Hu Z, Gadikota R, Cadiz M, Manzi MS, Ortiz Martinez FD, Vanga S, Chapman EG, Tibbetts SA, Karst SM. (2026) Maternal diet shapes milk bile acids to regulate neonatal growth through TGR5. Cell Rep 27;45(1):116744.
Manzi MS, Phophi L, de Oca JMF, Wilt HM, Ensberg KJ, Feswick A, Karst SM, Tibbetts SA. (2026) Early-life gammaherpesvirus infection results in an expanded long-term latent reservoir. Front Cell Infect Microbiol 16:1874370.
Morales Aparicio J, Hu Z, Peiper AM, Phophi L, Wilt HM, Nair MS, Winton HB, Blessing K, Romero-Gonzalez GP, Karst SM. (2025) ASBT governs neonatal bile acid homeostasis early in life despite its strong ileal repression. Am J Physiol Gastrointest Liver Physiol 329(2):G307-G312.
Peiper AM, Morales Aparicio J, Hu Z, Phophi L, Helm EW, Rubinstein RJ, Phillips M, Williams CG, Subramanian S, Cross M, Iyer N, Nguyen Q, Newsome R, Jobin C, Langel SN, Bucardo F, Becker-Dreps S, Tan XD, Dawson PA, Karst SM. (2024) Metabolic immaturity and breastmilk bile acid metabolites are central determinants of heightened newborn vulnerability to norovirus diarrhea. Cell Host Microbe 32(9):1488-1501
Subramanian S, Geng H, Wu L, Du C, Peiper AM, Bu HF, Chou PM, Wang X, Tan SC, Iyer NR, Khan NH, Zechner EL, Fox JG, Breinbauer R, Qi C, Yamini B, Ting JP, De Plaen IG, Karst SM, Tan XD. Microbiota regulates neonatal disease tolerance to virus-evoked necrotizing enterocolitis by shaping the STAT1-NLRC5 axis in the intestinal epithelium. (2024) Cell Host Microbe 32(10):1805-1821.
Peiper AM, Helm EW, Nguyen Q, Phillips M, Williams CG, Shah D, Tatum S, Iyer N, Grodzki M, Eurell LB, Nasir A, Baldridge MT, Karst SM. (2023) Infection of neonatal mice with the murine norovirus strain WU23 is a robust model to study norovirus pathogenesis. Lab Anim 52(6):119-129.
Helm EW, Peiper AM, Phillips M, Williams CG, Sherman MB, Kelley T, Smith HQ, Jacobs SO, Shah D, Tatum SM, Iyer N, Grodzki M, Morales Aparicio JC, Kennedy EA, Manzi MS, Baldridge MT, Smith TJ, Karst SM. (2022) Environmentally-triggered contraction of the norovirus virion determines diarrheagenic potential. Front Immunol. 13:1043746.
Mirabelli C, Jones MK, Young VL, Kolawole AO, Owusu I, Shan M, Abuaita B, Turula H, Trevino JG, Grigorova I, Lundy SK, Lyssiotis CA, Ward VK, Karst SM, Wobus CE. (2022) Human Norovirus Triggers Primary B Cell Immune Activation In Vitro. mBio 13(2):e0017522.
Grodzki M, Bluhm AP, Schaefer M, Tagmount A, Russo M, Sobh A, Rafiee R, Vulpe CD, Karst SM, Norris MH. (2022) Genome-scale CRISPR screens identify host factors that promote human coronavirus infection. Genome Med 14(1):10.
Roth AN, Helm EW, Mirabelli C, Kirsche E, Smith JC, Eurell LB, Ghosh S, Altan-Bonnet N, Wobus CE, Karst SM. (2020) Norovirus infection causes acute self-resolving diarrhea in wild-type neonatal mice. Nat Commun 11(1):2968.
Grau KR, Zhu S, Peterson ST, Helm EW, Philip D, Phillips M, Hernandez A, Turula H, Frasse P, Graziano VR, Wilen CB, Wobus CE, Baldridge MT, Karst SM. (2020) The intestinal regionalization of acute norovirus infection is regulated by the microbiota via bile acid-mediated priming of type III interferon. Nat Microbiol 5(1):84-92.
Grau KR, Roth AN, Zhu S, Hernandez A, Colliou N, DiVita BB, Philip DT, Riffe C, Giasson B, Wallet SM, Mohamadzadeh M, Karst SM. (2017) The major targets of acute norovirus infection are immune cells in the gut-associated lymphoid tissue. Nat Microbiol 2(12):1586-1591.
Zhu S, Jones MK, Hickman D, Han S, Reeves W, Karst SM. (2016) Norovirus antagonism of B-cell antigen presentation results in impaired control of acute infection. Mucosal Immunol 9(6):1559-1570.
Zhu S, Watanabe M, Kirkpatrick E, Murray AB, Sok R, Karst SM. (2015) Regulation of Norovirus Virulence by the VP1 Protruding Domain Correlates with B Cell Infection Efficiency. J Virol 90(6):2858-67.
Jones MK, Grau KR, Costantini V, Kolawole AO, de Graaf M, Freiden P, Graves CL, Koopmans M, Wallet SM, Tibbetts SA, Schultz-Cherry S, Wobus CE, Vinjé J, Karst SM. (2015) Human norovirus culture in B cells. Nat Protoc 10(12):1939-47.
Jones MK, Watanabe M, Zhu S, Graves CL, Keyes LR, Grau KR, Gonzalez-Hernandez MB, Iovine NM, Wobus CE, Vinjé J, Tibbetts SA, Wallet SM, Karst SM. (2014) Enteric bacteria promote human and mouse norovirus infection of B cells. Science 346(6210):755-9.
Hickman D, Jones MK, Zhu S, Kirkpatrick E, Ostrov DA, Wang X, Ukhanova M, Sun Y, Mai V, Salemi M, Karst SM. (2014) The effect of malnutrition on norovirus infection. mBio 5(2):e01032-13.
Zhu S, Regev D, Watanabe M, Hickman D, Moussatche N, Jesus DM, Kahan SM, Napthine S, Brierley I, Hunter RN 3rd, Devabhaktuni D, Jones MK, Karst SM. (2013) Identification of immune and viral correlates of norovirus protective immunity through comparative study of intra-cluster norovirus strains. PLoS Pathog 9(9):e1003592.
Kahan SM, Liu G, Reinhard MK, Hsu CC, Livingston RS, Karst SM. (2011) Comparative murine norovirus studies reveal a lack of correlation between intestinal virus titers and enteric pathology. Virology 421(2):202-10.
Liu G, Kahan SM, Jia Y, Karst SM. (2009) Primary high-dose murine norovirus 1 infection fails to protect from secondary challenge with homologous virus. J Virol 83(13):6963-8.
Changotra H, Jia Y, Moore TN, Liu G, Kahan SM, Sosnovtsev SV, Karst SM. (2009) Type I and type II interferons inhibit the translation of murine norovirus proteins. J Virol 83(11):5683-92.
Mumphrey SM, Changotra H, Moore TN, Heimann-Nichols ER, Wobus CE, Reilly MJ, Moghadamfalahi M, Shukla D, Karst SM. (2007) Murine norovirus 1 infection is associated with histopathological changes in immunocompetent hosts, but clinical disease is prevented by STAT1-dependent interferon responses. J Virol 81(7):3251-63.
Recommended Reading
New to the lab? Start here.
These papers provide useful background for the major concepts, approaches, and questions that shape our research.
Developmental origins of health and disease (DOHaD)
Gretchev et al., 2026 - Unpacking developmental programming
Provides the conceptual foundation for DOHaD and the idea that signals
experienced during critical developmental windows can have lasting effects on physiology and disease risk.
Hesketh et al., 2025 - Early life factors that affect obesity
Places obesity and metabolic health in a life-course framework, emphasizing how maternal and early-life environments can shape later adiposity.
Donato et al., 2023 - Developmental programming of metabolism by adipokines
Highlights adipose tissue as an active developmental and endocrine organ and
illustrates how early-life signals can program metabolic function.
Bile acid-microbiota interactions
Gretchev et al., 2026 - Unpacking developmental programming
Provides the conceptual foundation for DOHaD and the idea that signals experienced during critical developmental windows can have lasting effects on physiology and disease risk.
Hesketh et al., 2025 - Early life factors that affect obesity
Places obesity and metabolic health in a life-course framework, emphasizing how maternal and early-life environments can shape later adiposity.
Donato et al., 2023 - Programming of metabolism by adipokines during development
Highlights adipose tissue as an active developmental and endocrine organ and illustrates how early-life signals can program metabolic function.
Milk metabolites & maternal-infant signaling
Stinson et al., 2022 - Microbial metabolites: the next frontier in human milk
Introduces the concept that maternal microbial metabolites can be transmitted to infants through milk, providing a potential pathway for the maternal microbiome to influence early-life development.
Calvo-Lerma et al., 2024 - The human milk metabolome
Provides a comprehensive view of the diverse metabolites present in human milk and how the milk metabolome varies with maternal and perinatal factors.
Phophi et al., 2026 - Maternal diet shapes milk bile acids to regulate neonatal growth
Demonstrates that maternal diet alters the milk bile acid pool and that milk bile acids act as developmental signals regulating neonatal growth through TGR5.
Bile acid-microbiota interactions
Collins et al., 2022 - Bile acids and the gut microbiota
Provides a broad framework for the bidirectional relationship between the gut microbiota and bile acids, including microbial bile acid metabolism and the effects of bile acids on microbial communities and host signaling.
Sayin et al., 2013 - Gut microbiota regulate bile acid metabolism
A landmark mechanistic study showing that the microbiota reshapes the host bile
acid pool and, through these changes, alters FXR signaling and bile acid synthesis.
van Best et al., 2020 - Bile acids drive the newborn gut microbiota maturation
Demonstrates that bile acids are host-derived signals that shape the developing intestinal microbiota, with specific bile acids accelerating microbiota maturation in neonatal mice
Bile acid-microbiota interactions
Collins et al., 2022 - Bile acids and the gut microbiota
Provides a broad framework for the bidirectional relationship between the gut microbiota and bile acids, including microbial bile acid metabolism and the effects of bile acids on microbial communities and host signaling.
Sayin et al., 2013 - Gut microbiota regulate bile acid metabolism
A landmark mechanistic study showing that the microbiota reshapes the host bile
acid pool and, through these changes, alters FXR signaling and bile acid synthesis.
van Best et al., 2020 - Bile acids drive the newborn gut microbiota maturation
Demonstrates that bile acids are host-derived signals that shape the developing intestinal microbiota, with specific bile acids accelerating microbiota maturation in neonatal mice
Bile acid-microbiota interactions
Collins et al., 2022 - Bile acids and the gut microbiota
Provides a broad framework for the bidirectional relationship between the gut microbiota and bile acids, including microbial bile acid metabolism and the effects of bile acids on microbial communities and host signaling.
Sayin et al., 2013 - Gut microbiota regulate bile acid metabolism
A landmark mechanistic study showing that the microbiota reshapes the host bile
acid pool and, through these changes, alters FXR signaling and bile acid synthesis.
van Best et al., 2020 - Bile acids drive the newborn gut microbiota maturation
Demonstrates that bile acids are host-derived signals that shape the developing intestinal microbiota, with specific bile acids accelerating microbiota maturation in neonatal mice
Bile acid-microbiota interactions
Collins et al., 2022 - Bile acids and the gut microbiota
Provides a broad framework for the bidirectional relationship between the gut microbiota and bile acids, including microbial bile acid metabolism and the effects of bile acids on microbial communities and host signaling.
Sayin et al., 2013 - Gut microbiota regulate bile acid metabolism
A landmark mechanistic study showing that the microbiota reshapes the host bile
acid pool and, through these changes, alters FXR signaling and bile acid synthesis.
van Best et al., 2020 - Bile acids drive the newborn gut microbiota maturation
Demonstrates that bile acids are host-derived signals that shape the developing intestinal microbiota, with specific bile acids accelerating microbiota maturation in neonatal mice
Neonatal & early-life immunity
Kollmann et al., 2017 - Lessons from immune ontogeny
Explains how the distinctive immune responses of newborns reflect developmental adaptation rather than simple immune immaturity, and how these differences contribute to heightened susceptibility to infection.
Palma et al., 2026 - Immune development in early life
Provides a current framework for immune ontogeny and how maternal, microbial, nutritional, and environmental signals establish immune trajectories during critical windows of early life.
Macpherson et al., 2017 - How maternal diet and microbiota shape neonatal immunity
Highlights how maternal microbial and dietary metabolites transferred during pregnancy and through milk can shape immune development in the offspring
Bile acids & immune regulation
Fiorucci et al., 2026 - Secondary bile acids as immune mediators
Reviews how microbiota-derived secondary bile acids regulate both innate and adaptive immunity through diverse bile acid receptors and signaling pathways.
Hang et al., 2019 - Bile acid metabolites control TH17 and Treg differentiation
Identifies specific microbial bile acid metabolites that directly regulate TH17 and Treg differentiation, establishing a mechanistic link between bile acid metabolism and adaptive immunity.
Song et al., 2020 - Microbial bile acids regulate intestinal Treg homeostasis
Demonstrates that microbiota-derived bile acids regulate intestinal RORg+ Treg cells and are required for normal immune homeostasis in the gut.
Bile acids & immune regulation
Fiorucci et al., 2026 - Secondary bile acids as immune mediators
Reviews how microbiota-derived secondary bile acids regulate both innate and adaptive immunity through diverse bile acid receptors and signaling pathways.
Hang et al., 2019 - Bile acid metabolites control TH17 and Treg differentiation
Identifies specific microbial bile acid metabolites that directly regulate TH17 and Treg differentiation, establishing a mechanistic link between bile acid metabolism and adaptive immunity.
Song et al., 2020 - Microbial bile acids regulate intestinal Treg homeostasis
Demonstrates that microbiota-derived bile acids regulate intestinal RORg+ Treg cells and are required for normal immune homeostasis in the gut.
Bile acids & immune regulation
Fiorucci et al., 2026 - Secondary bile acids as immune mediators
Reviews how microbiota-derived secondary bile acids regulate both innate and adaptive immunity through diverse bile acid receptors and signaling pathways.
Hang et al., 2019 - Bile acid metabolites control TH17 and Treg differentiation
Identifies specific microbial bile acid metabolites that directly regulate TH17 and Treg differentiation, establishing a mechanistic link between bile acid metabolism and adaptive immunity.
Song et al., 2020 - Microbial bile acids regulate intestinal Treg homeostasis
Demonstrates that microbiota-derived bile acids regulate intestinal RORg+ Treg cells and are required for normal immune homeostasis in the gut.
Bile acids & immune regulation
Fiorucci et al., 2026 - Secondary bile acids as immune mediators
Reviews how microbiota-derived secondary bile acids regulate both innate and adaptive immunity through diverse bile acid receptors and signaling pathways.
Hang et al., 2019 - Bile acid metabolites control TH17 and Treg differentiation
Identifies specific microbial bile acid metabolites that directly regulate TH17 and Treg differentiation, establishing a mechanistic link between bile acid metabolism and adaptive immunity.
Song et al., 2020 - Microbial bile acids regulate intestinal Treg homeostasis
Demonstrates that microbiota-derived bile acids regulate intestinal RORg+ Treg cells and are required for normal immune homeostasis in the gut.
Bile acids & immune regulation
Fiorucci et al., 2026 - Secondary bile acids as immune mediators
Reviews how microbiota-derived secondary bile acids regulate both innate and adaptive immunity through diverse bile acid receptors and signaling pathways.
Hang et al., 2019 - Bile acid metabolites control TH17 and Treg differentiation
Identifies specific microbial bile acid metabolites that directly regulate TH17 and Treg differentiation, establishing a mechanistic link between bile acid metabolism and adaptive immunity.
Song et al., 2020 - Microbial bile acids regulate intestinal Treg homeostasis
Demonstrates that microbiota-derived bile acids regulate intestinal RORg+ Treg cells and are required for normal immune homeostasis in the gut.
Bile acids & immune regulation
Fiorucci et al., 2026 - Secondary bile acids as immune mediators
Reviews how microbiota-derived secondary bile acids regulate both innate and adaptive immunity through diverse bile acid receptors and signaling pathways.
Hang et al., 2019 - Bile acid metabolites control TH17 and Treg differentiation
Identifies specific microbial bile acid metabolites that directly regulate TH17 and Treg differentiation, establishing a mechanistic link between bile acid metabolism and adaptive immunity.
Song et al., 2020 - Microbial bile acids regulate intestinal Treg homeostasis
Demonstrates that microbiota-derived bile acids regulate intestinal RORg+ Treg cells and are required for normal immune homeostasis in the gut.
Bile acids & intestinal microbiota
Collins et al., 2022 - Bile acids and the gut microbiota
Provides a broad framework for the bidirectional relationship between the gut microbiota and bile acids, including microbial bile acid metabolism and the effects of bile acids on microbial communities and host signaling.
Sayin et al., 2013 - Gut microbiota regulate bile acid metabolism
A landmark mechanistic study showing that the microbiota reshapes the host bile
acid pool and, through these changes, alters FXR signaling and bile acid synthesis.
van Best et al., 2020 - Bile acids drive the newborn gut microbiota maturation
Demonstrates that bile acids are host-derived signals that shape the developing intestinal microbiota, with specific bile acids accelerating microbiota maturation in neonatal mice
Bile acids as endocrine signals
Makishima et al., 1999 - Bile acids are physiological ligands for FXR
Established bile acids as signaling molecules by identifying them as endogenous ligands for the nuclear receptor FXR, linking bile acid sensing to transcriptional regulation and metabolic homeostasis.
Kawamata et al., 2003 - TGR5 is a membrane receptor for bile acids
Identified TGR5 as a G protein-coupled bile acid receptor, establishing a second major pathway through which bile acids can signal to cells and tissues.
Thomas et al., 2009 - Bile acid sensing by TGR5 controls glucose homeostasis
Demonstrates that bile acids function as metabolic hormones through TGR5, promoting intestinal GLP-1 release and regulating glucose homeostasis.
Bile acids & antiviral immunity
Xiong et al., 2018 - TGR5 amplifies type I interferon responses
Demonstrates that TGR5 promotes antiviral immunity by enhancing IRF3 activation and type I interferon production, establishing bile acid signaling as a positive regulator of antiviral responses.
Liang et al., 2024 - FXR suppresses antiviral interferon responses
Shows that FXR interacts with activated IRF3 and impairs its DNA binding and transcriptional activity, revealing an opposing mechanism by which bile acid signaling can suppress antiviral immunity.
Winkler et al., 2020 - Bile acids restrict systemic alphavirus infection
Demonstrates that the microbiota-derived secondary bile acid DCA promotes systemic type I interferon responses to restrict chikungunya virus infection and dissemination.
Nagai et al., 2020 - Bile acids protect against respiratory virus infections
Shows that microbiota-derived bile acids enhance resistance to influenza and SARS-CoV-2 infection by limiting viral replication and damaging inflammation, with DCA–TGR5 signaling contributing to protection during influenza infection
Bile acids & noroviruses
Graziano et al., 2019 - Norovirus attachment and entry
Reviews how bile acids and other host factors influence norovirus attachment and entry, including direct interactions between bile acids and the viral capsid.
Grau et al., 2020 - Bile acids regulate intestinal norovirus infection
Demonstrates that microbiota-modified bile acids prime type III interferon responses and determine the regional outcome of murine norovirus infection.
Peiper et al., 2024 - Milk bile acids govern neonatal susceptibility to noroviruses
Demonstrates that microbiota-derived bile acids transmitted through milk activate TGR5-dependent antiviral immunity and protect neonatal mice from norovirus disease.
Adipose development
Wang et al., 2013 - Adipose tissue development and expansion
Uses lineage tracing to define when distinct white adipose depots develop and demonstrates that adipogenesis and expansion differ markedly between subcutaneous and visceral fat.
Merrick et al., 2019 - Adipocyte progenitor cell hierarchy
Identifies distinct adipose progenitor populations and establishes a developmental hierarchy in which DPP4+ progenitors give rise to ICAM1+ committed preadipocytes and mature adipocytes.
Sebo & Rodeheffer, et al., 2019 - Adipocyte lineage and adipose tissue development
Reviews how distinct adipocyte progenitor populations and developmental lineages establish adipose depots and determine their capacity for adipogenesis and remodeling.
bottom of page