The course aims to provide students with the knowledge related to the taxonomy and physiology of probiotic microorganisms, to the understanding of the mechanisms through which probiotics interact with the physiology of the host, to the learning of the scientific research strategies adopted to determine these mechanisms, to aspects related to the production technologies of probiotic microorganisms. The course also aims to provide students with the knowledge related to the regulations in force in the probiotic field.
Expected learning outcomes
At the end of the course the students will be able to critically evaluate products containing probiotics, both from a microbiological and technological point of view. Furthermore, students will be able to establish the most suitable criteria for the selection of a microorganism to be used as a probiotic and for the scientific evaluation of its effectiveness.
Lesson period: Second semester
(In case of multiple editions, please check the period, as it may vary)
Interactions between microorganisms and the human organism; the classification of living organisms; notes on the concepts of superorganism, microbiota and microbiome. The origins of the probiotic approach; the definition of probiotic; the FAO/WHO guidelines. Description of the procedure necessary for the evaluation of a probiotic according to FAO/WHO. Taxonomic identification of genus and species. The microorganisms used as probiotics (lactic acid bacteria, bifidobacteria and other microorganisms used as probiotics). Characterization at the strain level: the international collections of microbial strains; molecular fingerprinting techniques for strain characterization: PFGE and RAPD. The problem of genetic stability in probiotics. Next generation probiotics and live biotherapeutics. The microorganisms present in food as potential probiotics: yogurt and traditional fermented products. Functional characterization of a probiotic: evaluation of gastro-intestinal transit resistance; strategies to increase gastro-intestinal transit survival: microencapsulation; bacterial adhesion to the intestinal epithelium. Methods for the study of bacterial adhesion. In vitro assay for studying the antagonism with reporter systems based on bioluminescence. Measurement of trans-epithelial electrical resistance (TEER). The strain-specificity of probiotic properties: the example of Lactobacillus paracasei. The reporter system for the study of NF-kappaB activation in Caco-2 cell line. Antagonism and antimicrobial activity of probiotics towards pathogens (assay for evaluating antagonistic activity, bacteriocins, reuterin). Introduction to probiotic safety. Tests for the evaluation of the safety of a probiotic: the deconjugation of bile salts; the production of D-lactic acid by probiotics and D-lactic acid acidosis; bacterial hemolysis; determination of the infectivity of probiotics in animal models. Assessment of the safety of a probiotic: antibiotic resistance in probiotics (intrinsic antibiotic resistance vs acquired resistance; resistance mechanisms; EFSA breackpoints). Risks for the human health of taking probiotics: discussion of some clinical cases. The use of probiotics for the management of adverse effects related to the consumption of antibiotics: discussion of recent scientific literature and how they have been addressed by the press. A solution to safety problems: products containing inactivated probiotic microorganisms (paraprobiotics). The definition of synbiotics, bifidogenic and postbiotic. Probiotics and experimentation on humans: markers of type a, b and c. Example of a type "a" marker study: recovery studies. The label of probiotic products. The packaging for probiotic products. The difficulties associated with studying the efficacy of probiotics. The beneficial effects on human health attributed to probiotics (evaluation of available meta-analyzes). Brief description of the possible mechanisms of action of probiotics. The probiotic market; European legislation on probiotics (regulation 258/97 / EC on novel food, the concept of qualified safety presumption; QPS, legislation 1924/2006 on health claims, the consequences of EC regulation 1924/2006). The guidelines of the Italian Ministry of Health. Probiotics in zootechnics. Unconventional use of probiotic microorganisms: (i) biopreservation, the use of bacteria and their products for food preservation and safety; (ii) the probiotic approach to human health outside the gastrointestinal tract (oral cavity, vaginal mucosa, skin); (iii) the use of bacteria in clinical practice (the use of bacterial recombinants and drug delivery systems); (iv) fecal microbiota transplantation.
Prerequisites for admission
General Microbiology, Organic Chemistry, Biochemistry, Principles of Human Nutrition
The teaching will be delivered through lectures lasting 3 academic hours. Furthermore, an educational visit is planned to a company that produces microbial biomass.
Materials required for exam preparation: - presentations shown in class available in PDF format on the Ariel platform; - lecture notes; - additional information for students who do not participate in the lessons are available in Ariel in the session called "Course Information".
Assessement methods and criteria
- Type of exam: a written test with open answers lasting 60 minutes. Registration to the exams has to be done through the UNIMIA services (formerly SIFA). Students who participate in at least 75% of the lessons may, upon request, take the exam in oral form by appointment within 3 months from the end of the course. - Evaluation parameters: demonstration of acquisition of the concepts; ability to organize knowledge discursively. Importance will be given to the correct use of the specialized vocabulary. Furthermore, through specific questions, the autonomy of judgment of the candidate will be considered and evaluated. - Evaluation: mark out of thirty. - Method of communicating the results of the test: through the UNIMIA services (formerly SIFA) with the possibility of refusal of the vote by the student.