Infertile couples undergoing the use of assisted reproductive technology are a good study model to evaluate the microbiological signatures affecting reproductive health. We tested vaginal lavages, follicular fluids, embryo culture mediums, and seminal fluids from 47 couples for their microbiome composition and HPV infection. Twenty-five infertile couples were diagnosed with unexplained infertility, whereas 22 were diagnosed with explained infertility. Lactobacilli were dominant in the vaginal lavages of both patient groups, and the most abundant species was L. iners (CST III), which is linked to a decreased fertility rate. Besides this, L. gasseri—which is known to be associated with oocyte DNA fragmentation and decreased sperm mobility—was identified in the seminal fluids, follicular fluids, and embryo culture media of the unexplained infertility group. Prevotella was increased in the seminal fluids of the explained infertility group, along with HPV-positive seminal fluids: an infection commonly associated with infertility, especially male infertility. Prevotella has been described to negatively affect sperm motility. Taken together, these results suggest that the profiling of the reproductive tract microbiome can add new perspectives to human reproduction.

The current knowledge concerning the connection between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the renin–angiotensin system (RAS) system in the male reproductive apparatus is still limited, so dedicated studies are urgently required. Concerns about the male fertility consequences of SARS-CoV-2 infection have started to emerge, since epidemiologic studies observed that this coronavirus affects male patients more frequently and with increased severity, possibly because of the hormone-regulated expression of angiotensin-converting enzyme 2 (ACE2) receptor. A disturbance in fertility is also expected based on studies of the previous SARS-CoV infection, which targets the same ACE2 receptor when entering the host cells. In addition, bioinformatics analyses reveal the abundant expression of ACE2 receptor in the male reproductive tissues, particularly in the testis. It has been proposed that pharmacological intervention favoring the angiotensin-(1–7)/ACE2/Mas receptor pathway and increasing ACE2 expression and activity could greatly prevent inflammatory lesions in this area. Finally, in laboratories performing assisted reproductive technologies it is recommended that more attention should be paid not only to sperm quality but also to safety aspects. Data about the potential infectivity of seminal fluid are in fact conflicting and do not exclude risks for both personnel and patients. The potential infectivity of SARS-CoV-2 in reproductive male tissues should be strongly considered and further investigated for the proper management of in vitro fertilization procedures.

Type 1 Diabetes Mellitus (T1DM) is a chronic autoimmune disease that results in the destruction of pancreatic β cells, leading to hyperglycaemia and the need for lifelong insulin therapy. Although genetic predisposition and environmental factors are considered key contributors to T1DM, the exact causes of the disease remain partially unclear. Recent evidence has focused on the relationship between the gut, the oral cavity, immune regulation, and systemic inflammation. In individuals with T1DM, changes in the gut and oral microbial composition are commonly observed, indicating that dysbiosis may contribute to immune dysregulation. Gut dysbiosis can influence the immune system through increased intestinal permeability, altered production of short chain fatty acids (SCFAs), and interactions with the mucosal immune system, potentially triggering the autoimmune response. Similarly, oral dysbiosis may contribute to the development of systemic inflammation and thus influence the progression of T1DM. A comprehensive understanding of these relationships is essential for the identification of biomarkers for early diagnosis and monitoring, as well as for the development of therapies aimed at restoring microbial balance. This review presents a synthesis of current research on the connection between T1DM and microbiome dysbiosis, with a focus on the gut and oral microbiomes in pediatric populations. It explores potential mechanisms by which microbial dysbiosis contributes to the pathogenesis of T1DM and examines the potential of microbiome-based therapies, including probiotics, prebiotics, synbiotics, and faecal microbiota transplantation (FMT). This complex relationship highlights the need for longitudinal studies to monitor microbiome changes over time, investigate causal relationships between specific microbial species and T1DM, and develop personalised medicine approaches.

The morphology of spermatozoa is a fundamental aspect to consider in fertilization, sperm pathology, assisted reproduction and contraception. Head, neck, midpiece, principal and terminal part of flagellum are the main sperm components to investigate for identifying morphological features and related anomalies. Recently, scanning near-field optical microscopy (SNOM), which belongs to the wide family of nanoscopic techniques, has opened up new routes for the investigation of biological systems. SNOM is the only technique able to provide simultaneously highly resolved topography and optical images with a resolution beyond the diffraction limit, typical of conventional optical microscopy. This offers the advantage to obtain complementary information about cell surface and cytoplasmatic structures. In this work human spermatozoa both healthy and with morphological anomalies are analyzed by SNOM, to demonstrate the potentiality of such approach in the visualization of sperm morphological details. The combination of SNOM topography with optical (reflection and transmission) images enables to examine typical topographic features of spermatozoa together with underlying cytoplasmic structures. Indeed the head shape and inner components as acrosome and nucleus, and the organization of mitochondria in the midpiece region are observed. Analogously for principal tract of the tail, the ridges and the columns are detected in the SNOM topography, while their internal arrangement can be observed in the corresponding SNOM optical transmission images, without requiring specific staining procedures or invasive protocols. Such findings demonstrate that SNOM represents a versatile and powerful tool to describe topographical and inner structural details of spermatozoa simultaneously. This analysis could be helpful for better characterizing several morphological anomalies, often related to sperm infertility, which cannot be examined by conventional techniques all together.