Short-Chain Fatty-Acid-Producing Bacteria: Key Components of the Human Gut Microbiota.

Short-chain fatty acids (SCFAs) play a key role in health and disease, as they regulate gut homeostasis and their deficiency is involved in the pathogenesis of several disorders, including inflammatory bowel diseases, colorectal cancer, and cardiometabolic disorders. SCFAs are metabolites of specific bacterial taxa of the human gut microbiota, and their production is influenced by specific foods or food supplements, mainly prebiotics, by the direct fostering of these taxa. This Review provides an overview of SCFAs' roles and functions, and of SCFA-producing bacteria, from their microbiological characteristics and taxonomy to the biochemical process that lead to the release of SCFAs. Moreover, we will describe the potential therapeutic approaches to boost the levels of SCFAs in the human gut and treat different related diseases.

Histamine-producing bacteria and their role in gastrointestinal disorders.

INTRODUCTION: Gut microbiota produces thousands of metabolites, which have a huge impact on the host health. Specific microbial strains are able to synthesize histamine, a molecule with a crucial role in many physiologic and pathologic mechanisms of the host. This function is mediated by the histidine decarboxylase enzyme (HDC) that converts the amino acid histidine to histamine. AREAS COVERED: This review summarizes the emerging data on histamine production by gut microbiota, and the effect of bacterial-derived histamine in different clinical contexts, including cancer, irritable bowel syndrome, and other gastrointestinal and extraintestinal pathologies. This review will also outline the impact of histamine on the immune system and the effect of probiotics that can secrete histamine. Search methodology: we searched the literature on PubMed up to February 2023. EXPERT OPINION: The potential of modulating gut microbiota to influence histamine production is a promising area of research, and although our knowledge of histamine-secreting bacteria is still limited, recent advances are exploring their diagnostic and therapeutical potential. Diet, probiotics, and pharmacological treatments directed to the modulation of histamine-secreting bacteria may in the future potentially be employed in the prevention and management of several gastrointestinal and extraintestinal disorders.

CAR-T-Derived Extracellular Vesicles: A Promising Development of CAR-T Anti-Tumor Therapy.

Extracellular vesicles (EVs) are a heterogenous population of plasma membrane-surrounded particles that are released in the extracellular milieu by almost all types of living cells. EVs are key players in intercellular crosstalk, both locally and systemically, given that they deliver their cargoes (consisting of proteins, lipids, mRNAs, miRNAs, and DNA fragments) to target cells, crossing biological barriers. Those mechanisms further trigger a wide range of biological responses. Interestingly, EV phenotypes and cargoes and, therefore, their functions, stem from their specific parental cells. For these reasons, EVs have been proposed as promising candidates for EV-based, cell-free therapies. One of the new frontiers of cell-based immunotherapy for the fight against refractory neoplastic diseases is represented by genetically engineered chimeric antigen receptor T (CAR-T) lymphocytes, which in recent years have demonstrated their effectiveness by reaching commercialization and clinical application for some neoplastic diseases. CAR-T-derived EVs represent a recent promising development of CAR-T immunotherapy approaches. This crosscutting innovative strategy is designed to exploit the advantages of genetically engineered cell-based immunotherapy together with those of cell-free EVs, which in principle might be safer and more efficient in crossing biological and tumor-associated barriers. In this review, we underlined the potential of CAR-T-derived EVs as therapeutic agents in tumors.

The Role of Gut Microbiota and Leaky Gut in the Pathogenesis of Food Allergy.

Food allergy (FA) is a growing public health concern, with an increasing prevalence in Western countries. Increasing evidence suggests that the balance of human gut microbiota and the integrity of our intestinal barrier may play roles in the development of FA. Environmental factors, including industrialization and consumption of highly processed food, can contribute to altering the gut microbiota and the intestinal barrier, increasing the susceptibility to allergic sensitization. Compositional and functional alterations to the gut microbiome have also been associated with FA. In addition, increased permeability of the gut barrier allows the translocation of allergenic molecules, triggering Th2 immune responses. Preclinical and clinical studies have highlighted the potential of probiotics, prebiotics, and postbiotics in the prevention and treatment of FA through enhancing gut barrier function and promoting the restoration of healthy gut microbiota. Finally, fecal microbiota transplantation (FMT) is now being explored as a promising therapeutic strategy to prevent FA in both experimental and clinical studies. In this review article, we aim to explore the complex interplay between intestinal permeability and gut microbiota in the development of FA, as well as depict potential therapeutic strategies.

Ortho-Perio Risk Assessment and timing flowchart for lingual orthodontics in an interdisciplinary adult ortho-perio patient: A case report of "Perio-Guided" Orthodontic treatment.

INTRODUCTION: The treatment of ortho-perio patients is a challenge for the interdisciplinary team. Not only are adult patients with overt perio pathology involved, but any ortho patient, even young ones, can be a perio patient and vice versa. Diagnosis and risk assessment of every ortho-perio patient is essential to establish a correct treatment plan, schedule and prognosis. Orthodontics becomes a "Perio-Guided" Orthodontic Treatment and Periodontics a "Ortho-Guided Periodontal Treatment". MATERIAL AND METHODS: This case report presents a man with a very compromised dentition asking for a complete interdisciplinary rehabilitation treated with a combined ortho-perio treatment in lingual mechanics. The periodontal evaluation confirmed the possibility of performing orthodontic treatment after active periodontal treatment. Treatment objectives were the resolution of the crowding, the correction of the levels of the gingival margin, the bone levelling, the preparation for restorative spaces; the objectives of the latter prior to implant placement were: redistribution of space, optimization of the position of adjacent teeth and their parallelism, exploitation of edentulous sites to correct dental class II and placement of the least number of implants possible. After integrating the conventional perio risk assessment with a new Ortho-Perio Risk Assessment (OPRA), a lingual fixed appliance was applied with the help of miniscrews to correct class II division 2 by substituting the upper right first premolar into a canine and retracting the entire upper arch, while correcting the deep bite and optimising the occlusion. RESULTS: At the end of the treatment, the patient had molar relationships of class II on the right and class I on the left with a class I canine and the 14 in the position of 13. Incisal relationships were corrected, the position of the incisors was optimized, the spaces in the upper arch were fully resolved by orthodontics. During the treatment, orthodontics corrected the uneven gingival margin of the anterior teeth and levelled the bone. CONCLUSIONS: Correct ortho-perio risk assessment (OPRA) is necessary to plan the risk of expression of the periodontal phenotype in ortho-patient. OPRA and the lingual mechanics allowed an orthodontic resolution of the malocclusion and an enhancement of the perio-implant-restorative contributions. OPRA followed by periodontal therapy and lingual mechanics resolved the malocclusion by improving the restorative peri-implant conditions. Orthodontists and periodontists should be aware of the characteristics of the individual expression of the periodontal phenotype at the beginning of treatment and involve patients in the outcome, sequencing of combined treatments, ortho-perio retention and stability.

One-year impact of COVID-19 pandemic on Italian dental professionals: a cross-sectional survey.

BACKGROUND: COVID-19 pandemic has disrupted the daily work of the dental professionals, assuming unprecedented economic, managerial, and psychological implications. The aim of this cross-sectional survey was to analyze the extent of the impact linked to the imposed working conditions on the Italian dental team. METHODS: The survey was administered with a web-based form (Google Forms®; Google LLC, Mountain View, CA, USA) to Italian dentists and hygienists. To be enrolled in the study, participants had to reach the adulthood and agree to sign the privacy policy. The impact of COVID-19 was analyzed through a 27-items questionnaire, which was divided into 4 main domains: personal protective equipment (PPE), operative procedures, secretarial organization, and self-reported quality of life (including e-learning appraisal). RESULTS: A total of 614 between dentists and dental hygienists completed the questionnaire. Compared to the prepandemic period, the use of PPE such as face shields, surgical caps and disposable gowns were implemented after the COVID-19 outbreak. Almost the whole interviewed (99.9%) received the COVID-19 vaccine. An increased use of preoperatory mouthwashes and rubber dam was referred during the pandemic, while aerosolization (i.e., ultrasound) was drastically reduced. A certain number of respondents (30% dentists, 27% hygienists) suffered from work-related stresses during the pandemic until they desired to change jobs. E-learning was considered beneficial for the 70% of participants. CONCLUSIONS: COVID-19 pandemic influenced dental professionals' life, leading to a rearrangement of professional, managerial, and cultural life for both dentists and hygienists even after 1 year from the outbreak.

Lingual orthodontics in an adult patient with upper premolar extraction: Case report.

OBJECTIVE: To show with this case report that lingual orthodontics can be a solution in complex adult situation and with interdisciplinary approach. MATERIALS AND METHODS: The patient presented a dental and skeletal high angle class II division 1 with a previous extraction of one mandibular incisor. The strategy of treatment was upper first premolar-extraction to obtain a correction of the incisal-class II relationship with a normal lip function, a class II molar relationship on the right side and a class I on the left side. A lingual appliance and miniscrews were used. RESULTS: The lingual orthodontic treatment with miniscrews responded to the occlusal objectives with a good upper incisors torque and retraction control. DISCUSSION: Limits and advantages of lingual orthodontics were discussed. CONCLUSION: Lingual mechanics can provide good results from both an aesthetic and function point of view in adult complex extractions case. It ensures aesthetics during treatment, incisor control during retraction. Miniscrews were also useful to overcome the periodontal limits and enhance the anchorage.