About

Professor Claudio Gonzalez is a faculty member in the Department of Microbiology and Cell Science at the University of Florida. His research group focuses on a significant group of enzymes known as esterases, which includes carboxylesterases, arylesterases, and thioesterases. These enzymes are of particular interest in his studies, indicating a specialized focus on their biochemical properties and potential applications. Professor Gonzalez contributes to the department's mission by engaging in research that advances understanding of these enzymes, supporting the broader field of microbiology and cell science.

Research topics

• Biochemistry
• Biology
• Microbiology
• Immunology
• Molecular biology
• Botany
• Endocrinology
• Cell biology
• Horticulture
• Food science

Selected publications

• A critical evaluation of methodological and mechanistic insights on probiotic-derived extracellular vesicles

  Frontiers in Nutrition · 2025-08-29 · 4 citations

  reviewOpen access

  Probiotic extracellular vesicles (pEVs) have emerged as promising postbiotics with potential applications in inflammatory diseases, infections, allergies, cancer treatment, autoimmune disorders, and even neurological and degenerative conditions. Yet despite the surge in research on pEVs, critical gaps and inconsistencies in study design, methodology, and mechanistic understanding hinder unlocking their full potential. This literature review provides a concise introduction to beneficial bacterial EVs, mechanistic insights into their role in interkingdom interactions, and current challenges in pEV research. We highlight methodological inconsistencies in model selection, control design, and effect measurement, discuss their consequences and provide recommendations to improve experimental rigor and comparability of results. These include methodological considerations like standardization strategies for pEV preparation, purification, formulation, and administration as well as general study design questions. Finally, we outline key avenues for future research, emphasizing the need for biomarkers to track pEV biodistribution, the identification of effector molecules, and a deeper understanding of their mechanistic targets, as well as their interactions with food components and their use as delivery systems, among others. By addressing these challenges, this review aims to provide a roadmap for advancing pEV research and facilitating their transition into clinical and biotechnological applications.

  PublisherOA PDFDOI

• Nutritional and functional characterization of legume protein concentrates for sustainable food development: in vivo effects in Sprague-Dawley rats

  2025-05-29

  dissertationSenior author

  The growing global population, projected to reach between 9 and 10 billion people by 2050, highlights the need for sustainable and nutritious food sources. Conventional food systems, which significantly contribute to ecological issues such as greenhouse gas emissions and deforestation, underline the need for alternative protein sources that are both sustainable and nutritionally beneficial. In this context, plant-based proteins, especially those derived from legumes, are gaining attention due to their nutritional benefits, such as the essential bioactive compounds they contain. Legumes like lupine, chickpeas, beans, peas, fava beans, and lentils account for 80% of global production, with a 44% increase in Europe in recent years. As a result, large quantities of by-products from these legumes, such as defective seeds, pods, and skins, are generated, which are traditionally used for animal feed. However, when properly processed, these by-products can be transformed into valuable ingredients for human consumption. Additionally, their gluten-free nature improves the nutritional profile of gluten-free products and helps reduce the glycemic index of foods. The incorporation of plant proteins in food products requires a detailed analysis of characteristics such as amino acid composition, molecular weight, structure, and functional properties. The functionality of these proteins is closely related to their molecular properties in different states (native, intermediate, or denatured). Furthermore, the antinutritional factors present in legumes must be considered, as they can affect nutritional quality. These compounds are present in protein concentrates and isolates at higher concentrations than in raw seeds, limiting their applicability in food formulation. Despite the great potential of legume proteins as alternatives to animal proteins, there are significant challenges related to amino acid composition, the presence of antinutritional factors, and the need to improve their functionality. Overcoming these challenges is key to enhancing the viability of legume proteins as sustainable and nutritious alternatives in global protein sources. Protein concentrates from legume by-products have the potential to meet essential nutritional requirements and serve as a viable and sustainable alternative to animal proteins, providing comparable or superior nutritional benefits while helping to meet the growing demand for environmentally friendly and health-oriented protein sources. The main objective of this doctoral thesis is to identify and characterize legume-based protein alternatives for human food formulation, with an emphasis on their nutritional quality and functional properties to support the development of sustainable and health-promoting food products. To this end, the following specific objectives have been formulated: (1) To characterize the nutritional and functional quality of protein concentrates from by-products of four legume seeds (common bean, lentil, lupine, and pea) from a physicochemical perspective; (2) To investigate in vivo how the incorporation of protein concentrates from legume seed by-products, as the sole protein source, affects daily food and water intake, excretion patterns, overall body composition, and food preference in ad libitum-fed Sprague-Dawley rats; (3) To investigate the effect of selected protein concentrates from legume seed by-products on hematological and metabolic parameters, as well as on gut microbiota composition, in ad libitum-fed Sprague-Dawley rats.

  PublisherDOI

• Lactobacillus johnsonii N6.2 Phospholipids Induce T Cell Anergy upon Cognate Dendritic Cell Interactions

  Metabolites · 2025-04-22 · 1 citations

  articleOpen accessSenior authorCorresponding

  Background/Objectives: Lactobacillus johnsonii N6.2 is a gut symbiont with probiotic properties. L. johnsonii N6.2 delayed the progression of type 1 diabetes (T1D) in diabetic-prone rats. The probiotic intake demonstrated immune cell modulation in healthy volunteers, leading to improved wellness and fewer reported symptoms like headaches and abdominal pain. These systemic immune-modulating benefits are attributed to L. johnsonii N6.2’s bioactive fractions, including extracellular vesicles (EVs) and purified phospholipids (PLs). We have previously shown that L. johnsonii N6.2 PLs modulate dendritic cell (DC) function towards a regulatory-like phenotype. Here, we further characterize the immune regulatory effects of L. johnsonii N6.2 PLs on adaptive immunity, specifically upon DC and T cell interactions. We hypothesized that PL-stimulated DCs suppress T cell-mediated responses to maintain tolerance in intra- and extra-intestinal sites. Methods: Bone marrow-derived dendritic cells (BMDCs) were generated from Sprague-Dawley rats and stimulated with L. johnsonii N6.2 PLs. Isogenic T cells were isolated from PBMCs obtained via terminal exsanguination. In vitro cellular assays, co-culture experiments, gene expression analysis by qRT-PCR, and flow cytometry assays were conducted to assess the immune regulatory effects of L. johnsonii N6.2 PLs. Results: The PL-stimulated BMDCs upregulated DC regulatory markers and exhibited an immature-like phenotype with reduced surface expression of maturation markers but increased surface migratory molecules (ICAM-1). These BMDCs presented immunosuppressive functions upon cognate T cell interactions and in the presence of TCR stimulation. Specifically, PL-stimulated BMCDs suppressed Th1 effector function and induced the expression of T cell anergy-related genes after co-culturing for 72 h. Conclusions: This study highlights the immune regulatory capacity of L. johnsonii N6.2’s bioactive components on adaptive immunity, specifically that of purified PLs on DC:T cell-mediated responses leading to immunosuppression. Our findings suggest that L. johnsonii N6.2-purified PLs play a role in regulating adaptive immunity, offering potential benefits for managing immune-related diseases like T1D.

  PublisherOA PDFDOI

• Maternal Light and Temperature Modulate Seed Longevity in Arabidopsis

  2025-11-04

  articleOpen access

  Seed longevity is defined as the length of time a seed can preserve its germination capacity, and it is a relevant trait for disciplines from agriculture to ecology. Seed longevity is a polygenic trait influenced by genetic and environmental factors. Despite the recognized impact of climate change on many reproductive aspects of plant biology, studies focused on how these new conditions affect this trait are scarce. In this work, we describe how environmental conditions to which the plants are exposed during seed development, termed the maternal environment effect, modulate longevity of the new developed seeds. Eight Arabidopsis thaliana natural accessions were grown on a combination of four different environmental scenarios: 22°C or 27°C at both low-light or high-light intensity. The combined effect of both 27°C and high light conditions generated seeds with higher longevity, although the effect is accession dependent. Similarly, an anticorrelation was found between seed dormancy and seed longevity when seeds were developed at 22ºC under HL conditions, highlighting the importance of the environment in determining final seed properties. Transcriptome analysis of the Bor-4 accession, whose seeds presented the highest difference in longevity between conditions, revealed a very dynamic composition of stored mRNAs modulated by the four different environmental conditions during seed development. Nearly 80% of the differentially expressed genes exhibited a combined effect when both temperature and light-intensity were altered. Results suggest that seeds subjected to higher temperature and light intensity are primed with antioxidant defences and have a higher potential to deploy raffinose family oligosaccharides, which would be critical to safeguard cellular components during the ageing process.

  PublisherOA PDFDOI

• Maternal Light and Temperature Modulate Seed Longevity in Arabidopsis

  bioRxiv (Cold Spring Harbor Laboratory) · 2025-10-19

  preprint

  Abstract Seed longevity is defined as the length of time a seed can preserve its germination capacity, and it is a relevant trait for disciplines from agriculture to ecology. Seed longevity is a polygenic trait influenced by genetic and environmental factors. Despite the recognized impact of climate change on many reproductive aspects of plant biology, studies focused on how these new conditions affect this trait are scarce. In this work, we describe how environmental conditions to which the plants are exposed during seed development, termed the maternal environment effect, modulate longevity of the new developed seeds. Eight Arabidopsis thaliana natural accessions were grown on a combination of four different environmental scenarios: 22°C or 27°C at both low-light or high-light intensity. The combined effect of both 27°C and high light conditions generated seeds with higher longevity, although the effect is accession dependent. Similarly, an anticorrelation was found between seed dormancy and seed longevity when seeds were developed at 22°C under HL conditions, highlighting the importance of the environment in determining final seed properties. Transcriptome analysis of the Bor-4 accession, whose seeds presented the highest difference in longevity between conditions, revealed a very dynamic composition of stored mRNAs modulated by the four different environmental conditions during seed development. Nearly 80% of the differentially expressed genes exhibited a combined effect when both temperature and light-intensity were altered. Results suggest that seeds subjected to higher temperature and light intensity are primed with antioxidant defences and have a higher potential to deploy raffinose family oligosaccharides, which would be critical to safeguard cellular components during the ageing process.

  PublisherDOI

• Lactobacillus johnsonii N6.2 improves glycemia and reduces diabetes-induced organ injury in the db/db mice model

  Journal of Endocrinology · 2025-10-01 · 1 citations

  article

  Diabetes mellitus is a complex metabolic disorder characterized by hyperglycemia and the associated comorbidities. Type 2 diabetes is also associated with the dysfunction of liver, kidney and nervous system. In addition, an altered microbiota is frequently observed in subjects with type 2 diabetes. In this study, a db/db (diabetic) mouse model of type 2 diabetes was used to elucidate the beneficial effects of the probiotic Lactobacillus johnsonii N6.2. To evaluate metabolic effects, we performed metabolomics on liver samples, and RNA-seq from the liver and visceral adipose tissue, followed by qRT-PCR validation. Using L. johnsonii N6.2 extracellular vesicles, we evaluated lipid accumulation in hepatocytes. Finally, the gut microbiome of db/db mice was profiled using 16S rRNA sequencing. We observed that administration of the probiotic improved glycemic levels and decreased diabetes scores and type 2 diabetes-associated injury to the pancreas, liver and kidneys. Liver metabolomic and transcriptome analyses identified biomarkers of L. johnsonii N6.2 activity, including modulation of the vitamin K pathway, upregulation of FGF21, a key regulator of glucose and lipid metabolism, and alternations in selected circadian genes. This study elucidates the beneficial effects of L. johnsonii N6.2, against the common symptoms of type 2 diabetes, highlighting its potential as an adjuvant therapeutic agent.

  PublisherDOI

• The Sdp-SH3b2 domain contained in Lactobacillus johnsonii N6.2-derived extracellular vesicles inhibit murine norovirus replication

  Frontiers in Immunology · 2024-12-05 · 9 citations

  articleOpen access

  The internalization of Lactobacillus johnsonii N6.2 extracellular vesicles (EVs) by cells results in a significant induction of the 2’,5’-oligoadenylate synthetase (OAS) pathway. It also induces expression of IFI44L, MX1, MX2 and DDX60 . In this work, we evaluated whether the antiviral response induced by L. johnsonii N6.2-derived EVs, has an inhibitory effect on an RNA viral insult using murine norovirus (MNV-1) as the viral infection model. We found that RAW 264.7 Macrophages treated with EVs significantly decreased the levels of MNV-1 genome. These results were consistent with an increase in expression of Oas1b, Oas2, Oasl, Mx1, Mx2 and Ifi44l (6 hours post infection). Out of six proteins enriched in EVs, we found that SH3b2 domain of Sdp was the only protein effector molecule able to recapitulate the activation of the OAS pathway. In C57BL6 mice, the administration of live L. johnsonii N6.2, EVs, and Sdp-SH3b2/liposomes significantly decreased MNV-1 titers in the distal ileum, in contrast to the controls with PBS and liposomes alone that did not affect MNV-1. These results establish that the SH3b2 domain of Sdp, which is enriched in L. johnsonii derived EVs, is an effector molecule in EVs that can orchestrate the control of viral infections in vivo .

  PublisherDOI

• Bile promotes Lactobacillus johnsonii N6.2 extracellular vesicle production with conserved immunomodulatory properties

  Scientific Reports · 2024-05-28 · 12 citations

  articleOpen access

  Recently, Lactobacillus johnsonii N6.2-derived extracellular vesicles (EVs) were shown to reduce apoptosis in human beta cell lines and stimulate insulin secretion in human islets. Our goal was to identify a physiologically relevant environmental condition that induces a hypervesiculation phenotype in L. johnsonii N6.2 and to evaluate if transcriptional changes are involved in this process. Culturing this strain in the presence of 0.2% bovine bile, which mimics a stressor encountered by the bacterium in the small intestine, resulted in approximately a 100-fold increase in EVs relative to cells grown in media without bile. Whole transcriptome analysis of cells grown with bile revealed upregulation of several peptidoglycan hydrolases as well as several genes involved in fatty acid utilization. These results suggest that the hypervesiculation phenotype may be the result of increased cell wall turnover combined with increased accumulation of phospholipids, in agreement with our previous proteomic and lipidomics results. Additionally, EVs isolated from L. johnsonii N6.2 grown in presence of bile maintained their immunomodulatory properties in host-derived βlox5 pancreatic and THP-1 macrophage cell lines. Our findings suggest that in L. johnsonii N6.2 vesiculogenesis is significantly impacted by the expression of cell wall modifying enzymes and proteins utilized for exogenous fatty acid uptake that are regulated at the transcriptional level. Furthermore, this data suggests that vesiculogenesis could be stimulated in vivo using small molecules thereby maximizing the beneficial interactions between bacteria and their hosts.

  PublisherOA PDFDOI

• Erucic acid utilization by Lactobacillus johnsonii N6.2

  Frontiers in Microbiology · 2024-11-25 · 2 citations

  articleOpen access

  A multivariate nutritional analysis indicated that the consumption of erucic acid-rich food, a fatty acid (FA) found primarily in rapeseed and mustard oil, was positively correlated with higher counts of lactic acid bacteria (LAB). Furthermore, we showed Lactobacillus johnsonii N6.2, as well as other species of LAB tested from the former Lactobacillus genus, were able to efficiently use erucic acid (EA) as the source of FA. In this work, we identified significant changes induced in the FA profiles of L. johnsonii cultured with EA as the source of FA. We performed global transcriptomics to identify genes and pathways involved in EA utilization. It was found that L. johnsonii incorporates external fatty acids via a FakA/FakB and the plsX/plsY/plsC pathway for phosphatidic acid synthesis. It was found that cells grown in MRS with EA (MRS-E) significantly upregulated fakB2 and fakB4 when compared to cells grown in standard MRS with tween 80 as the source of FA. Additionally, in MRS-E, L. johnsonii N6.2 induced the expression of plsY2, plsC2 and plsC4 while the expression of pslX was constitutive during short term EA exposure. LC–MS analyses revealed that L. johnsonii N6.2 rapidly incorporates EA and synthesizes a variety of long chain fatty acids, including the health-relevant omega-9 monounsaturated fatty acids such as nervonic and gondoic acids.

  PublisherOA PDFDOI

• Pasteurization of human milk affects the miRNA cargo of EVs decreasing its immunomodulatory activity

  Scientific Reports · 2023-06-21 · 20 citations

  articleOpen access

  Abstract In this report, we evaluated the effect of the pasteurization (P) process of mother’s own milk (MOM) on the miRNA content of extracellular vesicles (EVs) and its impact on innate immune responses. Differences in size or particle number were not observed upon pasteurization of MOM (PMOM). However, significant differences were observed in the EV membrane marker CD63 and miRNA profiles. miRNA sequencing identified 33 differentially enriched miRNAs between MOM EV and PMOM EV . These changes correlated with significant decreases in the ability of PMOM EV to modulate IL-8 secretion in intestinal Caco2 cells where only MOM EV were able to decrease IL-8 secretion in presence of TNFα. While EVs from MOM EV and PMOM EV were both able to induce a tolerogenic M2-like phenotype in THP-1 macrophages, a significant decrease in the transcript levels of IL-10 and RNA sensing genes was observed with PMOM EV . Together, our data indicates that pasteurization of MOM impacts the integrity and functionality of MOM EV , decreasing its EVs-mediated immunomodulatory activity. This data provides biomarkers that may be utilized during the optimization of milk processing to preserve its bioactivity.

  PublisherOA PDFDOI

Frequent coauthors

• Graciela L. Lorca

  University of Florida

  52 shared

• Alexei Savchenko

  University of Calgary

  30 shared

• Alexander F. Yakunin

  University of Toronto

  26 shared

• Greg Brown

  University of Toronto

  24 shared

• A. Joachimiak

  University of Chicago

  20 shared

• Michael Proudfoot

  University of Toronto

  20 shared

• Ekaterina Kuznetsova

  Sechenov University

  20 shared

• Fernando A. Pagliai

  University of Florida

  18 shared