Investigation of the role of nutrition and gut microbiome in well-being as well as in the etiology of disease and morbidity in humans

Gut microbiota, one of the most complex and dense microbial ecosystems, is recognized for its crucial role in human health. Imbalance in the dynamic interactions among intestinal microbial communities, a phenomenon called dysbiosis, has been related to many pathological conditions, such as inflammatory bowel disease, irritable bowel syndrome, obesity, and colorectal cancer. The modulation of Gut Microbiome (GM) through the consumption of functional foods can restore gut homeostasis and reverse leaky gut state. Recently, the development of advanced sequencing tools paved the way for significant breakthroughs in Gut Microbiome research while many studies have revealed the fundamental importance of the microbiome in shaping host immune responses.
Supported by and building on the FUNglucan project (2018-2022) and through applying holistic approaches such as NMR Metabolomics and Next Generation Sequencing, we aim at identifying dietary factors with enhanced prebiotic activity in view of the development of novel food products which promote health and quality of life, of the elderly in particular, through exploiting the Greek biodiversity. In vitro, in vivo, ex vivo as well as clinical intervention studies are being implemented.

Selected Publications

• Vlassopoulou, M., Paschalidis, N., Savvides, A.L., Saxami, G., Mitsou, E.K., Kerezoudi, E.N., Koutrotsios, G., Zervakis, G.I., Georgiadis, P., Kyriacou, A., Pletsa, V. Immunomodulating Activity of Pleurotus eryngii Mushrooms Following Their In Vitro Fermentation by Human Fecal Microbiota. J Fungi (Basel). 2022 , 8.  
  https://doi:10.3390/jof804032
• Saxami, G., Kerezoudi, E.N., Mitsou, E.K., Koutrotsios, G., Zervakis, G.I., Pletsa, V., Kyriacou, A. Fermentation supernatants of pleurotus eryngii mushroom ameliorate intestinal epithelial barrier dysfunction in lipopolysaccharide-induced caco-2 cells via upregulation of tight junctions. Microorganisms 2021, 9.
  https://doi.org/10.3390/microorganisms9102071
• Vlassopoulou, M., Yannakoulia, M., Pletsa, V., Zervakis, G.I., Kyriacou, A. Effects of fungal beta-glucans on health-a systematic review of randomized controlled trials. Food Funct.2021, 12, 3366–3380.
  https://doi.org/10.1039/d1fo00122a
• Boulaka, A.; Christodoulou, P.; Vlassopoulou, M.; Koutrotsios, G.; Bekiaris, G.; Zervakis, G.I.; Mitsou, E.K.; Saxami, G.; Kyriacou, A.; Zervou, M.; Georgiadis, P.; Pletsa, V. Genoprotective Properties and Metabolites of β-Glucan-Rich Edible Mushrooms Following Their In Vitro Fermentation by Human Faecal Microbiota. Molecules 2020,  25, 3554. https://doi.org/10.3390/molecules25153554
• Mitsou EK, Saxami G, Stamoulou E, Kerezoudi E, Terzi E, Koutrotsios G, Bekiaris G, Zervakis GI, Mountzouris KC, Pletsa V, Kyriacou A. Effects of Rich in Β-Glucans Edible Mushrooms on Aging Gut Microbiota Characteristics: An In Vitro Study. Molecules 2020, Jun 18;25(12):2806.
  https://doi:10.3390/molecules25122806 
• Turunen KT, Pletsa V, Georgiadis P, Triantafillidis JK, Karamanolis D, Kyriacou A. Impact of β-glucan on the Fecal Water Genotoxicity of Polypectomized Patients. Nutr Cancer 2016, May-Jun;68(4):560-7.
  https://doi:10.1080/01635581.2016.1156713 

Investigation of the molecular mechanisms of genotoxicity, carcinogenesis and cell death

The development of bioactive compounds against selected therapeutic targets and their evaluation in relevant preclinical disease models/intervention studies, in the context of drug design and discovery, is of utmost importance for chemoprevention and treatment.
The Comet Assay has been widely used for detecting primary DNA damage in individual cells. The micronucleus (MN) test is also a well-established assay for detecting clastogenicity and aneugenicity. We utilize these two assays in order to assess the genotoxicity or anti-genotoxicity of novel bioactive synthetic or natural compounds or mixtures.
On the other hand, chemotherapeutic agents inducing DNA damage may activate cell death by apoptosis or necrosis. The molecular basis underlying the decision- making process is currently the subject of intense investigation because a deeper understanding of how a given chemotherapy affects all of the signaling pathways involved in cell death is highly relevant in order to develop more effective therapeutics and prevent recurrence. We assess geno/cytotoxicity of novel bioactive lead compounds and further study the molecular mechanism underlying their action in view of their use as chemotherapeutic drugs. We emphasize on the identification/validation of new prognostic chemo-sensitivity/resistance biomarkers, related to cell death pathways and the cell’s response to DNA damaging insults.

Selected Publications

• Boulaka, A.; Christodoulou, P.; Vlassopoulou, M.; Koutrotsios, G.; Bekiaris, G.; Zervakis, G.I.; Mitsou, E.K.; Saxami, G.; Kyriacou, A.; Zervou, M.; Georgiadis, P.; Pletsa, V. Genoprotective Properties and Metabolites of β-Glucan-Rich Edible Mushrooms Following Their In Vitro Fermentation by Human Faecal Microbiota. Molecules 2020, 25, 3554. https://doi.org/10.3390/molecules25153554     
• Papadodima, O., Moulos, P., Koryllou, A., Piroti, G., Kolisis, F., Chatziioannou, A., Pletsa, V. Modulation of pathways underlying distinct cell death mechanisms in two human lung cancer cell lines in response to SN1 methylating agents treatment. PLoS ONE 2016, 11. https://doi.org/10.1371/journal.pone.0160248  

In collaboration with the Biomimetics & Nanobiotechnology Program, ICB, NHRF

In recent years, research groups worldwide have focused attention on the development of safe biocompatible, nanosized systems for encapsulating, protecting and delivering sensitive bioactive components with health-promoting properties, including the prevention and treatment of cancer. In parallel, combination of neutraceuticals with orally delivered chemotherapeutic drugs has emerged in the context of nano-sized delivery systems due to their excellent biocompatibility, negligible biotoxicity, manufacturing scalability and mainly enhanced bioavailability affecting cancer therapy efficacy.
As nanocarriers are becoming very important as drug delivery systems,  in collaboration with the Program of Biomimetics & Nanobiotechnology, we evaluate, in vitro, ex vivo and in vivo, the biological action of nano-dispersions as carriers of lipophilic lead compounds in target tissues of relevance.

Selected Publications

• Theochari, I., Mitsou, E., Nikolic, I., Ilic, T., Dobricic, V., Pletsa, V., Savic, S., Xenakis, A., Papadimitriou, V. Colloidal nanodispersions for the topical delivery of Ibuprofen: Structure, dynamics and bioperformances. J. Mol. Liq. 2021, 334. https://doi.org/10.1016/j.molliq.2021.116021
• Theochari, I., Ilic, T., Nicolic, I., Dobricic, V., Tenchiou, A., Papahatjis, D., Savic, S., Xenakis, A., Papadimitriou, V., Pletsa, V. Biological evaluation of oil-in-water microemulsions as carriers of benzothiophene analogues for dermal applications. Biomimetics 2021, 6, 1–15.
  https://doi.org/10.3390/BIOMIMETICS6010010.
• Demisli, S.; Mitsou, E.; Pletsa, V.; Xenakis, A.; Papadimitriou, V. Development and Study of Nanoemulsions and Nanoemulsion-Based Hydrogels for the Encapsulation of Lipophilic Compounds. Nanomaterials 2020, 10, 2464. https://doi.org/10.3390/nano10122464
• Mitsou E, Pletsa V, Sotiroudis G, Panine P, Zoumpanioti M, Xenakis A. Development of a Microemulsion for Encapsulation and Delivery of Gallic Acid. The Role of Chitosan. Colloids and Surfaces B. Biointerfaces 2020.
  https://doi.org/10.1016/j.colsurfb.2020.110974
• Theochari I, Papadimitriou V, Papahatzis D, Assimomytis N, Pappou E,  Pratsinis H, Xenakis A, Pletsa V (2018) “Oil-in-water microemulsions as hosts for benzothiophene-based cytotoxic compounds: an effective combination” Biomimetics 2018,3,13. https://doi:1033.90/biomimetics3020013 

MSc Programs

The members of the group participate in the administration/organization and teaching in

• “Oncology: from Oncogenesis to Therapy” interdepartmental postgraduate programme, Joint Master’s Degree, University of Crete/National Hellenic Research Foundation.
  http://www.english.med.uoc.gr/oncology
• “Bioenterpreneurship” , interdepartmental, interdisciplinary postgraduate programme, Joint Master’s Degree, University of Thessaly/National Hellenic Research Foundation. Dr. V. Pletsa is member of the Interdepartmental and Coordination Committee.
  http://bioepixirin.bio.uth.gr/

PhD theses

2018-present: M. Vlassopoulou “Prebiotic, Immunomodulating and Anti-cancer activity of β-glucans: a mechanistic study”, Harokopio University, Department of Nutrition and Dietetics (ongoing in NHRF and HUA).

2016-2020: Ioanna Theochari “Development of Nanodispersions as carriers of bioactive compounds. Biological applications”, University of Thessaly, School of Health Sciences, Department of Biochemistry & Biotechnology, Larissa 2020.
https://www.didaktorika.gr/eadd/bitstream/10442/47075/1/47075.pdf

2016-2019: Evgenia Mitsou “Development of microemulsions for the administration of bioactive compounds”, University of Ioannina, School of Health Sciences, Department of Biological Applications and Technology, Laboratory of Biotechnology, Ioannina 2019. https://www.didaktorika.gr/eadd/bitstream/10442/46670/1/46670.pdf

MSc theses

2020-present

• E. Kotsa “Epigenetics of obesity and type II diabetes”, Postgraduate program “Biology applications in Medicine” http://mde-biol-med-applications.biol.uoa.gr/news.html, Faculty of Biology, NKUA (ongoing).

2020-2021

• A. Psychaki “Conducting Clinical studies in Greece and abroad” Post graduate program Bioepixirin (Joint Master’s Degree, University of Thessaly/National Hellenic Research Foundation).
• F. Tsikrika “Use of e-commerce as a tool of drug marketing by Greek pharmaceutical companies” Post graduate program Bioepixirin (Joint Master’s Degree, University of Thessaly/National Hellenic Research Foundation).

2019-2020

• E. Lianou “Metabolic analysis and anti-genotoxic imprint of the products of the in vitro fermentation of edible Greek mushrooms by the intestinal microbiome of healthy volunteers”, Post graduate program “Microbial Biotecnology”, Department of Biology, NKUA.
  
• M. Prevezanou "Induction of immunogenic cell death during anticancer therapy-Clinical applications and challenges", Post graduate program “Oncology: from Oncogenesis to Therapy”, (Joint Master’s Degree, University of Crete/National Hellenic Research Foundation).

2018-2019

• C.M. Papachristophorou “Business plan for the creation of a standard unit of production and development of functional and innovative agricultural products” Post graduate program Bioepixirin (Joint Master’s Degree, University of Thessaly/National Hellenic Research Foundation).
• M. Chatzitheodorou “Retrospective study for the presence of Arboviruses Usutu and Toscana in human cerebrospinal fluid samples with molecular methods”, Post graduate program Bioepixirin (Joint Master’s Degree, University of Thessaly/National Hellenic Research Foundation).
  
• M. Zotou “In vitro biological assessment of the potential anticarcinogenic action of small organic compounds: benzoxazines” Post graduate program Bioepixirin (Joint Master’s Degree, University of Thessaly/National Hellenic Research Foundation).
  
• P. Ragias “Nanodispersions as carriers of bioactive compounds” by Panteleimon Ragias Post graduate program Bioepixirin (Joint Master’s Degree, University of Thessaly/National Hellenic Research Foundation).

Graduate theses

2018-2022

• K. Skiada “"Biological evaluation of gelled microemulsions as carriers of bioactive substances for use in cosmetics, medicines and foods", Department of Biological Applications and Technology, University of Ioannina (ongoing).
• O. Konstanta “In vitro evaluation of the health-promoting properties of the fungus Pleurotus eryngii”, Department of Biology, School of Science, NKUA (ongoing).
• E. Vlahou “Investigation of Prebiotic, Immunomodulating and Anti-cancer activity of Pleurotus ostreatus και Ganoderma lucidum, edible mushrooms of the Greek flora”, Department of Biology, School of Science, NKUA, 2019.
• N. Georgakopoulos “Nanodispersions as carriers of bioactive compounds. Applications in anticancer therapy”, Department of Biology, School of Science, NKUA, 2018.

Erasmus Internship

15/4/-15/7.2019: Mr. Αhmad Maswadeh & Miss Mays Aqrouq, Jordan University of Science and Technology / Faculty of Science and Art / Department of Genetic Engineering and Biotechnology, in the context of their visit at the Department of Biology, NKUA during the second semester of 2018-2019. Both students were trained in molecular and cellular biology techniques with special emphasis on modern approaches for the cytotoxicity and genotoxicity assessment of chemical as well as dietary agents.

Training Internships

2018-2021: A. Lemonidis (Department of Biology, NKUA), D. Kaligosi (Department of Biotechnology, AUA), M. Paxinou (Department of Computer Science & Biomedical Informatics, UTH), F. Karamitsa (Department of Biology, NKUA).

• The members of the group actively and regularly participate in communicating Science to the public, students and pupils, within the frame of dedicated events (i.e. Researcher's Night, Athens Science and Technology Festival, Open ICB weeks) as well as in NHRF’s Science Communication & Dissemination Events annual events; "Youth, Antiaging and Longevity: Modern Approaches to Biological Age through the Historical and Biological Sciences", March 2018 / “Nutrition & Health”, May 2020.
  www.eie.gr/nhrf/institutes/ibmcb/index-en-ibcmb.html
• Dr. V. Pletsa is Vice-President of the NHRF’s Research Ethics Committee http://www.eie.gr/ethics_committee_gr.html 

Building on the FUNglucan project (Development of a novel FUNctional food enriched with β-glucans isolated from edible mushrooms of Greek habitats) and the collaborations developed during its implementation, we will intensify the effort to raise funding for pursuing this line of activity:

Already, Nutribiome (Nutrition-Gut Microbiome Interactions in Health & Disease), a proposal on the establishment of a sustainable Network for Excellencecompetent to address all main aspects of the axis Nutrition-Gut Microbiome-Gut barrier integrity-Disease Prevention, has been  submitted in the  HORIZON-WIDERA-2021-ACCESS-03 Twinning call (coordinator Dr. V. Pletsa) and is currently under evaluation. Through the proposed action, we would like to scale up current activities through a strategic partnership with the Nutrition Gut Brain Axis Interactions (NGBI) research center in Orebro University (OU), Sweden and the Department of Genomics and Health-FISABIO in Spain, two leading counterparts at EU level.

To the same direction, the proposal Pleuromics (Evaluation of the health-promoting properties of edible mushrooms of the Pleurotus eryngii species through -omics technologies, in view of the production of a novel functional food) has been submitted (coordinator Dr. V. Pletsa) in the context of the national call Research & Innovation Synergies in the Attica Region, and is currently under evaluation. The proposal links academia to food industry, aiming at producing a novel functional food with a high commercialization perspective. Main partner in this effort is PAPADOPOULOS SA, one of the biggest food industries in Greece, active in food innovation.

Overall, the main targets are: 

• Development of innovative approaches in the R&I domain of Nutrition-Gut Microbiome interactions through joint research activities, knowledge transfer and exchange of best practice with leading counterparts at EU level.
• Synergies with industry towards the commercial exploitation of research results and production of novel functional foods
• Enhancing education, mobility and training of young scientists.

Cancer remains the second most common cause of death worldwide and a major hurdle in health care. New strategies should be implemented in basic, translational, and clinical cancer research to improve diagnosis and treatment and, ultimately, decrease the overall cancer burden in Greece and worldwide.

Our group participates in the Hellenic Network for Precision Medicine on Cancer (HNPMC; https://oncopmnet.gr/) which aims at the application of NGS holistic DNA analysis, in order to assist in the development of targeted therapies and high quality prevention and health diagnostic services, as well as in the Joint Action on European Networks of Expertise (JANE) on cancer, 2022-2025, (EU4H).

Furthermore, we also participate in the recently submitted proposals: ACETRAC (Athens Centre of Excellence for Translational Cancer Research at ACCC) in the context of the HORIZON-WIDERA-2022-ACCESS-01-two-stage (Teaming for Excellence) call and MultiOncoMIcS (Multi-OMICS biomarkers discovery and implementation for cancer prevention) in the context of the HORIZON-WIDERA-2021-ACCESS-03: Twinning call.

(In collaboration with the Biomimetics & Nanobiotechnology Program, ICB, NHRF)

The main objective of this line of activity is the development of biocompatible and safe nanocarriers as protective encapsulation systems to improve the solubility and increase bioavailability of certain nutraceuticals with potential chemopreventive activity, such as vitamin D3, R-(+)-limonene and propolis extracts. Moreover, co-administration of nutraceuticals with orally delivered chemotherapeutic agents will be also investigated through in vitro and in vivo biological evaluation. We are planning to intensify our efforts to raise funding, through competitive national and international calls, in order to support this cutting-edge research activity in the upcoming period.