Background: The human gastrointestinal tract is home to a wide variety of microorganisms. For some decades now, bacteria known as probiotics have been added to various foods because of their beneficial effects for human health. Evidence indicates that probiotics significantly regulate gut microbiota, which is vital for digestion, metabolism, immune function, and mental health. Methods: We conducted a narrative review of available original research published in PubMed for the past ten years focusing on recent advancements that provide a thorough understanding of the relationship between the gastrointestinal system and the brain. Results: Recent advances in research have focused on the importance of gut microbiota in influencing mental health. The microbiota–gut–brain axis is a complex, bidirectional communication network linking the central nervous system and the gastrointestinal tract, which highlights how the gut and brain are deeply interconnected and influence each other in ways that affect our overall health, emotions, and behavior. This powerful link is a major area of research as scientists discover more about how gut health can impact mental well-being. Conclusions: A comprehensive understanding of microbiota composition and mechanisms involved in these interactions between the gut and the brain could shape future medical and therapeutic approaches. It would balance scientific explanation with clinical relevance, offering insights into how understanding the brain–gut axis can revolutionize our approach to treating mental health and gastrointestinal disorders.

Hepatocellular adenomas are benign endothelial tumors of the liver, mostly associated with female individual users of estrogen-containing medications. However, the precise factors underlying the selective development of hepatic adenomas in certain females remain elusive. Additionally, the conventional profile of individuals prone to hepatic adenoma is changing. Notably, male patients exhibit a higher risk of malignant progression of hepatocellular adenomas, and there are instances where hepatic adenomas have no identifiable cause. In this paper, we theorize the role of the human gastrointestinal microbiota, specifically, of bacterial species producing β-glucuronidase enzymes, in the development of hepatic adenomas through the estrogen recycling pathway. Furthermore, we aim to address some of the existing gaps in our knowledge of pathophysiological pathways which are not yet subject to research or need to be studied further. As microbial β-glucuronidases proteins recycle estrogen and facilitate the conversion of inactive estrogen into its active form, this process results in elevated levels of unbound plasmatic estrogen, leading to extended exposure to estrogen. We suggest that an imbalance in the estrobolome could contribute to sex hormone disease evolution and, consequently, to the advancement of hepatocellular adenomas, which are estrogen related.

Stroke–heart syndrome (SHS), a critical yet underrecognized condition, encompasses a range of cardiac complications that arise following an ischemic stroke. This narrative review explores the pathophysiology, clinical manifestations, and implications of SHS, focusing on the complex interplay between the brain and the heart. Acute ischemic stroke (AIS) triggers autonomic dysfunction, leading to a surge in catecholamines and subsequent myocardial injury. Our review highlights the five cardinal manifestations of SHS: elevated cardiac troponin (cTn) levels, acute myocardial infarction, left ventricular dysfunction, arrhythmias, and sudden cardiac death. Despite the significant impact of these complications on patient outcomes, there is a notable absence of specific guidelines for their management. Through a comprehensive literature search, we synthesized findings from recent studies to elucidate the mechanisms underlying SHS and identified gaps in the current understanding. Our findings underscore the importance of early detection and multidisciplinary management of cardiac complications post-stroke. Future research should focus on establishing evidence-based protocols to improve clinical outcomes for stroke patients with SHS. Addressing this unmet need will enhance the care of stroke survivors and reduce mortality rates associated with cardiac complications.

This study examines the effects of metformin on brain functions focusing on the variability of the results reported in the literature. While some studies suggest that metformin may have neuroprotective effects in diabetic patients, others report an insignificant impact of metformin on cognitive function, or even a negative effect. We propose that this inconsistency may be due to intrinsic cellular-level variability among individuals, which we term “biovariance”. Biovariance persists even in demographically homogeneous samples due to complex and stochastic biological processes. Additionally, the complex metabolic actions of metformin, including its influence on neuroenergetics and neuronal survival, may produce different effects depending on individual metabolic characteristics.

In-stent restenosis (ISR) remains a clinically relevant cause of recurrent ischemia and repeat revascularization despite progressive refinements in stent design and implantation technique. Contemporary data indicate that restenosis-related target lesion revascularization (TLR) has declined from bare-metal stent (BMS) to early- and newer-generation drug-eluting stents (DESs), yet ISR continues to accumulate over long-term follow-up and is associated with worse outcomes than PCI for de novo lesions. Mechanistically, ISR is a time-dependent, heterogeneous process dominated early by neointimal hyperplasia—triggered by mechanical endothelial injury, delayed re-endothelialization, inflammation/oxidative stress, vascular smooth muscle cell phenotypic switching, and extracellular matrix deposition—and later by in-stent neoatherosclerosis, which may confer a higher-risk plaque substrate and overlap with thrombotic complications. Clinically, ISR frequently presents as an acute coronary syndrome (ACS) rather than stable symptoms, underscoring the prognostic relevance of prompt recognition and mechanism-informed management. Patient-level risk determinants repeatedly reported across cohorts include diabetes mellitus, chronic kidney disease, dyslipidemia, hypertension, and smoking, while lesion/procedural factors include small vessel caliber, long/complex or bifurcation lesions, multiple stent layers, and suboptimal stent expansion. Intravascular imaging (OCT/IVUS) is central to phenotyping ISR mechanisms (e.g., underexpansion, calcific neoatherosclerosis, stent fracture, homogeneous hyperplasia) and can guide targeted prevention and therapy. This review synthesizes current evidence on ISR biology and risk factors to support risk stratification, preventive strategies, and individualized management.

Hypothalamic hamartomas (HH) are infrequent, non-neoplastic malformations of the hypothalamus with heterogeneous clinical features, with symptoms including gelastic seizures, central precocious puberty, and cognitive or behavioral deficits. This narrative review synthesizes current knowledge regarding the etiology, clinical manifestations, diagnostic advances, and therapeutic approaches for HH. Genetic insights highlight the role of postzygotic mosaicism and dysregulated Sonic Hedgehog signaling in HH development, emphasizing their relevance in potential therapeutic strategies. Diagnostic modalities such as MRI, PET, and SEEG are pivotal in identifying and characterizing HHs, enabling precise treatment planning. Therapeutic interventions span pharmacological, surgical, and neuromodulatory approaches. While surgical approaches, such as transcallosal resection or stereotactic radiosurgery, can offer considerable seizure control, newer modalities, such as laser interstitial laser thermal therapy (LITT) as well as stereotactic radiofrequency thermocoagulation, prioritize minimizing both cognitive and behavioral sequelae. The use of pharmacologic management and neuromodulation provides adjuvant benefits, specifically in drug-resistant epilepsy; despite progress, limitations still remain, including variability of outcomes and not enough long-term studies. This review underscores the need for multidisciplinary care and advanced research to optimize outcomes and improve the quality of life for patients with HH.