Multiple demographic or economic parameters contribute to the origin of emerging infections, for example: poverty, urbanization, climate change, conflicts and population migrations. All these factors are a challenge to assess the impact (present and future) of parasitic diseases on public health. The intestine is a major target of these infections; it is a nutrient-rich environment harbouring a complex and dynamic population of 100 trillion microbes: the microbiome. Most researches on the microbiome focus on bacteria, which share the gut ecosystem with a population of uni- and multi cellular eukaryotic organisms that may prey on them.  Our interest focuses on the families of eukaryotic microbes inhabiting the intestine, called intestinal eukaryome, that include fungi, protists and helminths. Knowledge on the reciprocal influence between the microbiome and the eukaryome, and on their combined impact on homeostasis and intestinal diseases is scanty and can be considered as an important emerging field. Furthermore, the factors that differentiate pathogenic eukaryotes from commensals are still unknown. This book presents an overview of the science presented and discussed in theFirst Eukaryome Congress held from October 16th to 18th, 2019 at the Pasteur Institute in Paris.This book covers the following topics:Phylogenetic, prevalence, and diversity of intestinal eukaryotic microbes; and their (still enigmatic) historical evolution and potential contributions to mucosal immune homeostasis.Integrative biology to study the molecular cell biology of parasite-host interactions and the multiple parameters underlining the infectious process.The exploitation of tissue engineering and microfluidics to establish three-dimensional (3D) systems that help to understand homeostasis and pathological processes in the human intestine.

Dr. Nancy Guillen received her degree in Biology in 1972 at the Universidad Central de Venezuela in Caracas and her Doctorat d'Etat in Natural Sciences with speciality in Microbiology at the University of Paris Sud-Orsay (France) in 1979. She obtained her habilitation diploma at the same University in 1986 and got a permanent position as senior researcher at the National Centre for Research (CNRS-France) in 1982, she was a visiting fellow at Rockefeller University (1979) and at the Public Health Research Institute, New York City (1986-1987). Currently, Dr Nancy Guillén is Emeritus Research Director at the CNRS, a position she has held since 2015. Currently she is interested in understand the cellular and molecular mechanisms responsible for the invasion of tissue by the parasitic amoebaEntamoeba histolytica, the agent aetiology of amoebiasis. This infectious disease is endemic world wide. Dr Nancy Guillén has been consecutively vice-president of the scientific council ofPasteur Institute (until 2011), member of the scientific council in the department-INRA Animal Health (2006-2016), scientific coordinator of the Pasteur-Weizmann Council (2008-2013) and co-director of the department of Cell Biology and Infection, Institut Pasteur until 2014. Responsible for the cell biology section at the French National Laboratory of Excellence supporting Parasitology (Labex ParaFrap) and lead the Post-Doctoral Program in this Labex until end of 2019. Her research activity is documented by more than 182 publications in international peer-reviewed journals

Eukaryome: Emerging field with profound translational potential.- Resolving amoebozoan encystation from Dictyostelium evo-devo and amoebozoan comparative genomics.- Integrative omics analysis of the effect of bacteria on the resistance of Entamoeba histolytica to oxidative stress.- Histomonas meleagridis molecular traits from past to future.- Exploring the biology and evolution of Blastocystis and its role in the microbiome.- Advances in the study of Blastocystis spp. in Mexico: prevalence, genetic diversity, clinical association and their possible role in the human intestine.- Cryptosporidium infection in Bangladesh children.- The current molecular epidemiological scenario of Cryptosporidium, Giardia and Blastocystis in Spain. Implication for public health.- The protozoome of the periodontal sulcus: from health to disease.- Tritrichomonas spp. and Their Impact on Gut Immune Homeostasis.- Contribution of host immunity to the development ofEntamoeba histolytica-induced liver abscess.- Oxidative Stress And Heat Stress In Experimental Amoebic Liver Abscess.- Role of Extracellular Traps promoted by intestinal parasites. Relationship with virulence.- Parasite secretory molecules in host-parasite interaction.- The Role of Host PKC during Intracellular Cryptosporidium Infection.- Immune response triggered by Entamoeba histolytica in a 3D-intestinal model.- Receptors for phagocytosis and trogocytosis in Entamoeba histolytica.- PtdIns(3,4,5)P3 binding protein screening reveals unique molecules involved in endocytic processes.- Molecular insights into E. histolytica mediated host tissue invasion.- Vesicular trafficking in Entamoeba histolytica is essential for its virulence.- MOLECULAR CHARACTERIZATION OF Entamoeba histolytica tRNA GENES.- Gene silencing and overexpression to study pathogenicity factors of Entamoeba histolytica.- Polyadenylation machineries in intestinal parasites: latest advances in the protozoan parasite Entamoeba histolytica.- Probiotics as anti-Giardia defenders: Overview on putative control mechanisms.- A protocol to quantify cellular morphodynamics: from cell labelling to automatic image analysis.-