The human gut microbiome is integral to maintaining systemic physiological balance, with accumulating evidence emphasizing its critical role in reproductive health. This review investigates the bidirectional interactions between the gut microbiota and the female reproductive system, mediated by neuroendocrine, immune, and metabolic pathways, constituting the gut–reproductive axis. Dysbiosis, characterized by microbial imbalance, has been linked to reproductive disorders such as polycystic ovary syndrome (PCOS), endometriosis, infertility, impaired spermatogenesis, and pregnancy complications. These associations can be explained by immunological dysregulation, systemic inflammation, altered sex hormone metabolism, and hypothalamic–pituitary–gonadal (HPG) axis disturbances. This review aims to clarify the molecular and cellular mechanisms underpinning gut–reproductive interactions and to evaluate the feasibility of microbiome-targeted therapies as clinical interventions for improving reproductive outcomes.

Background/Objectives: Infertility in both men and women can be significantly influenced by oxidative stress (OS), which occurs due to an imbalance between reactive oxygen species (ROS) and the body’s antioxidant defenses. In women, OS disrupts oocyte maturation, implantation, and the viability of the embryo; in men, it impairs sperm quality, reduces motility, and damages DNA integrity. This review explores existing research on how dietary and lifestyle interventions can reduce OS and enhance reproductive health outcomes. Methods: We conducted a comprehensive review of clinical, translational, and molecular studies exploring the mechanisms by which OS affects fertility, as well as the efficacy of nutritional and behavioral strategies. The interventions evaluated include weight management, regular exercise, micronutrient supplementation, antioxidant-rich diets, smoking and alcohol cessation, and stress-reduction techniques. Results: Specific dietary components such as zinc, selenium, vitamins C and E, and polyphenols have been found to neutralize reactive oxygen species (ROS) and enhance gamete function. OS is additionally reduced through lifestyle modifications, including minimizing harmful exposures, managing stress, and participating in moderate physical activity. Biomarkers such as ROS levels, total antioxidant capacity, 8-OHdG, and DNA fragmentation index are essential for assessing the effectiveness of interventions. Conclusions: Fertility in both sexes can be improved, and oxidative stress significantly reduced, through a multimodal approach incorporating dietary and lifestyle changes. There are encouraging opportunities to improve reproductive health through customized approaches that are informed by biomarker profiles. To incorporate these treatments into regular fertility care, future studies should concentrate on standardized procedures and long-term results.

Background: Telomere attrition and mitochondrial dysfunction are two fundamental aspects of aging. Calorie restriction (CR) is the best strategy to postpone aging since it can enhance telomere attrition, boost antioxidant capacity, and lower the generation of reactive oxygen species (ROS). Since ROS is produced by mitochondria and can readily travel to cell nuclei, it is thought to be a crucial molecule for information transfer between mitochondria and cell nuclei. Important variables that affect the quality and functionality of sperm and may affect male reproductive health and fertility include telomere length, mitochondrial content, and the ratio of mitochondrial DNA (mtDNA) to nuclear DNA (nDNA). Telomere damage results from mitochondrial failure, whereas nuclear DNA remains unaffected. This research aims to investigate potential associations between these three variables and how they might relate to body mass index. Methods: Data were collected from 82 men who underwent IVF/ICSI at the University Hospital of Ioannina’s IVF Unit in the Obstetrics and Gynecology Department. Evaluations included sperm morphology, sperm count, sperm motility, and participant history. To address this, male participants who were categorized into three body mass index (ΒΜΙ) groups—normal, overweight, and obese—had their sperm samples tested. Results: For both the normal and overweight groups, our results show a negative connection between relative telomere length and ΒΜI. As an illustration of a potential connection between mitochondrial health and telomere maintenance, a positive correlation was found for the obese group. Only the obese group’s results were statistically significant (p < 0.05). More evidence that longer telomeres are associated with lower mitochondrial content can be found in the negative connection between telomere length and mitochondrial content in both the normal and overweight groups. However, the obese group showed a positive association. The data did not reach statistical significance for any of the three groups. These associations may affect sperm quality since telomere length and mitochondrial concentration are indicators of cellular integrity and health. Moreover, the ratio of mtDNA to nDNA was positively correlated with the relative telomere lengths of the obese group, but negatively correlated with the normal and overweight groups. In every group that was studied, the results were not statistically significant. According to this, male fertility may be negatively impacted by an imbalance in the copy number of the mitochondrial genome compared to the nuclear DNA in sperm. Conclusions: Essentially, the goal of our work is to determine whether mitochondria and telomere length in human sperm interact. Understanding these connections may aid in the explanation of some male infertility causes and possibly contribute to the creation of new treatment modalities for problems pertaining to reproductive health. The functional implications of these connections and their applications in therapeutic settings require further investigation.

Thalassemia is an autosomal recessive hereditary chronic hemolytic anemia characterized by a partial or complete deficiency in the synthesis of alpha- or beta-globin chains, which are essential components of adult hemoglobin. Mutations in the globin genes lead to the production of unstable globin chains that precipitate within cells, causing hemolysis. This shortens the lifespan of mature red blood cells (RBCs) and results in the premature destruction of RBC precursors in the bone marrow. Regular red blood cell transfusions are the standard treatment for thalassemia. However, these transfusions can lead to increased iron overload, which can impair vital systems such as the liver, heart, ovaries, and endocrine system. Focusing on female reproductive endocrinology, recurrent blood transfusions can cause iron accumulation in the pituitary and hypothalamus, leading to hypogonadotropic hypogonadism (HH), the most common endocrinopathy in these patients, affecting 40–91% of women. Recurrent transfusions and the resulting iron overload can also lead to oxidative stress and ovarian damage in patients with beta-thalassemia major (BTM). Despite advancements in iron chelation therapy, hypothalamic–pituitary damage associated with HH contributes to subfertility and sexual dysfunction, often with little to no recovery. In women exposed to gonadotoxic drugs, particularly those with BTM, anti-Mullerian hormone (AMH)—a marker of ovarian reserve—is frequently used to assess ovarian damage. This review aims to explore the pathophysiology of β-thalassemia and its major clinical manifestations, with a focus on endocrine complications and their impact on ovarian reserve. It also investigates how metabolomics can provide insights into the disease’s metabolic alterations and inform current and emerging therapeutic strategies to mitigate complications and optimize patient outcomes, potentially leading to more effective and personalized treatments.

Pre-implantation genetic testing (PGT) is a crucial process for selecting embryos created through assisted reproductive technology (ART). Couples with chromosomal rearrangements, infertility, recurrent miscarriages, advanced maternal age, known single-gene disorders, a family history of genetic conditions, previously affected pregnancies, poor embryo quality, or congenital anomalies may be candidates for PGT. Preimplantation genetic testing for aneuploidies (PGT-A) enables the selection and transfer of euploid embryos, significantly enhancing implantation rates in assisted reproduction. Fluorescence in situ hybridization (FISH) is the preferred method for analyzing biopsied cells to identify these abnormalities. While FISH is a well-established method for identifying sperm aneuploidy, NGS offers a more comprehensive assessment of genetic material, potentially enhancing our understanding of male infertility. Chromosomal abnormalities, arising during meiosis, can lead to aneuploid sperm, which may hinder embryo implantation and increase miscarriage rates. This review provides a comparative analysis of fluorescence in situ hybridization (FISH) and next-generation sequencing (NGS) in sperm evaluations, focusing on their implications for preimplantation genetic testing. This analysis explores the strengths and limitations of FISH and NGS, aiming to elucidate their roles in improving ART outcomes and reducing the risk of genetic disorders in offspring. Ultimately, the findings will inform best practices in sperm evaluations and preimplantation genetic testing strategies.

Background/Objectives: Traditional semen analysis techniques frequently result in incorrect male infertility diagnoses, despite advancements in assisted reproductive technology (ART). Reduced fertilization potential, decreased embryo development, and lower pregnancy success rates are associated with elevated DNA Fragmentation Index (DFI), which has been proposed as a diagnostic indicator of sperm DNA integrity. Improving reproductive outcomes requires incorporating DFI into predictive models due to its diagnostic importance. Methods: In this study, semen samples were stratified into low and high DFI groups across two datasets: the “Reference” dataset (162 samples) containing sperm motility (A, B, and C), total sperm count, and morphology percentage, and the “ORP” dataset (37 samples) with the same features plus oxidation-reduction potential (ORP). We trained and evaluated four machine learning (ML) models—Logistic Regression, Support Vector Machines (SVM), Bernoulli Naive Bayes (BNB), and Random Forest (RF)- using three feature subsets and three preprocessing techniques (Robust Scaling, Min-Max Scaling, and Standard Scaling). Results: Feature subset selection had a significant impact on model performance, with the full feature set (X_all) yielding the best results, and the combination of Robust and MinMax scaling forming the most effective preprocessing pipeline. Conclusions: ORP proved to be a critical feature, enhancing model generalization and prediction performance. These findings suggest that data enrichment, particularly with ORP, could enable the development of ML frameworks that improve prognostic precision and patient outcomes in ART.