This reasearch project is part of the MIND Foods HUB. During the last decades, the incidence of autoimmune and allergic diseases (AADs) has seen an exponential increase worldwide. These disorders are characterized by abnormal alterations in Th1/Th2 populations, driven by an improper activation of regulatory T cells. Reduced exposure to intestinal microorganisms – which are thought to have co-evolved alongside the human species – has been identified as one of the factors accused of taking part in the improper activation of Treg populations. Consequently, the hypothesis of an impoverished gut microbiota has grown over the years. And so have its names: from the ‘hygiene hypothesis’ to the ‘old friends hypothesis’, and from the ‘microbial deprivation hypothesis’ to the most recent and well-accepted ‘biodiversity hypothesis’. Several elements are thought to have reduced a profuse contact with microorganisms: the industrial revolution and the resulting redistribution of people, moving from the countryside to urban areas, the less frequent contact with pets and animals, families becoming smaller and having fewer children, caesarean delivery, the lack of breastfeeding, the large use of antibiotics during the first years of life. In addition, as societies evolved, so did dietary regimens. Nowadays, the ever-increasing demand for healthy and fast foods has triggered technical and technological advancements around food safety. This is especially true for ready-to-eat (RTE) products, which, by definition, are a category of commercially available goods intended for human consumption, and requiring no cooking or any other intervention whatsoever, before ingestion. So modern diets – poor in raw or fermented foods – combined with the extreme pre-packaging cleaning procedures fresh products have to undergo, have drastically reduced our windows of exposure to microbial agents, and could therefore play a clear role in the increasing incidence of AADs. The fact that food should still be considered a vehicle for essential microorganisms – and in particular when in its raw or fermented forms – is the rationale behind this Ph.D. project. In specific, raw rocket salads were chosen as a model, due to their growing market importance, consumption rate during quick busy-day healthy meals, and presence in urban households and offices. Through this Ph.D. project microbial communities associated with different commercially available rocket salads will be analysed, characterised and compared (i.e. conventional, organic, RTE, non-washed pre-packed, freshly supplied loose salad, etc.), with the purpose of verifying whether farming and processing methods do affect microbial load diversity. A complete antibiotic resistance profile, by means of an E. coli BAC library of bacterial metagenomic DNA isolated from rocket salads, will also be produced. And finally, with the scope of designing a novel reinforced RTE salad, a library of lactic acid bacteria will be created – each of which characterised and selected based on the presence of functional activities, such as immunomodulatory capability, vitamin production, or myrosinase activity. In conclusion, this project will help us better understand whether the modern tendencies in dietary products consumption, with little fermented foods and high quantities of processed goods – irradiated, pasteurized, microfiltered, etc. – could have played a role in the increasing incidence of AADs. The possibility of using microorganisms in RTE products, resulting in microbial-reinforced products, will also be investigated. The basis for a new branch of research about microorganisms and their relevance in daily food intake will therefore be set.