Microbiota-Gut-Brain Axis Dysregulation in Alzheimer's Disease: Multi-Pathway Effects and Therapeutic Potential

Electroacupuncture intervention alleviates depressive-like behaviors and regulates gut microbiome in a mouse model of depression

Electroacupuncture (EA) is a neuroregulatory therapy for depression. Nonetheless, the effects of EA on the gut microbiome in mice models of depression are not well established. Here, using a chronic unpredictable mild stress (CUMS) model in mice, we evaluated the antidepressant effects of EA and changes in gut microbiota with behavioral tests and 16S rRNA gene sequencing. The results found that EA increased the time spent in the center area of the open-field test and the percentage of sucrose preference and reduced the immobility time in the tail suspension test in CUMS-treated mice. Furthermore, the genus Lachnoclostridium, Ruminococcaceae_UCG-002 and Rikenellaceae_RC9_gut_group were enriched in the CUMS group, which was positively correlated with depressive-like behaviors. Whereas phylum Actinobacteria and genus Allobaculum, Bifidobacterium, Dubosiella, Rikenella and Ileibacterium were enriched in the EA and CUMS + EA groups, all of which were negatively correlated with depressive-like behaviors. This study characterizes gut microbiota under EA treatment and provides new insights into the association of anti-depressive-like effects of EA and gut microbiota.

Advancing Neurological Health: Insights into Aging, Immunity, and Vascular Dynamics

This editorial provides an overview of recent advancements in the understanding and treatment of neurological disorders, focusing on aging, immunity, and blood flow, as featured in this special issue. The first section explores the importance of identifying biomarkers of aging and aging-related diseases, such as Alzheimer's Disease, highlighting the emerging role of saliva-based biomarkers and the gut-brain axis in disease diagnosis and management. In the subsequent section, the dysregulated immune systems associated with aging are discussed, emphasizing the intricate landscape of the immune system during aging and its bidirectional relationship with neuroinflammation. Additionally, insights into the involvement of Myeloid-Derived Suppressor Cells (MDSCs) in Multiple Sclerosis (MS) pathogenesis are presented. The third section examines the role of microglia in neuroinflammation and various neurological diseases, including age-related macular degeneration (AMD) and Tuberculous Meningitis (TBM). Furthermore, the therapeutic potential of stem cell and extracellular vesicle-based therapies for stroke is explored, along with molecular mechanism of how inflammation regulates cerebral and myocardial ischemia. Finally, the importance of blood flow in maintaining vascular health and its impact on neurological disorders are discussed, highlighting the potential of novel assessment methods for optimizing patient care. Overall, this special issue offers valuable insights into the complex mechanisms underlying neurological disorders and identifies potential avenues for therapeutic intervention.

The interaction between Mediterranean diet and intestinal microbiome: relevance for preventive strategies against frailty in older individuals

Age-related changes in intestinal microbiome composition and function are increasingly recognized as pivotal in the pathophysiology of aging and are associated with the aging phenotype. Diet is a major determinant of gut-microbiota composition throughout the entire lifespan, and several of the benefits of a healthy diet in aging could be mediated by the microbiome. Mediterranean diet (MD) is a traditional dietary pattern regarded as the healthy diet paradigm, and a large number of studies have demonstrated its benefits in promoting healthy aging. MD has also a positive modulatory effect on intestinal microbiome, favoring bacterial taxa involved in the synthesis of several bioactive compounds, such as short-chain fatty acids (SCFAs), that counteract inflammation, anabolic resistance, and tissue degeneration. Intervention studies conducted in older populations have suggested that the individual response of older subjects to MD, in terms of reduction of frailty scores and amelioration of cognitive function, is significantly mediated by the gut-microbiota composition and functionality. In this context, the pathophysiology of intestinal microbiome in aging should be considered when designing MD-based interventions tailored to the needs of geriatric patients.

Neuroinflammation and Neurodegenerative Diseases: How Much Do We Still Not Know?

The term "neuroinflammation" defines the typical inflammatory response of the brain closely related to the onset of many neurodegenerative diseases (NDs). Neuroinflammation is well known, but its mechanisms and pathways are not entirely comprehended. Some progresses have been achieved through many efforts and research. Consequently, new cellular and molecular mechanisms, diverse and conventional, are emerging. In listing some of those that will be the subject of our description and discussion, essential are the important roles of peripheral and infiltrated monocytes and clonotypic cells, alterations in the gut-brain axis, dysregulation of the apelinergic system, alterations in the endothelial glycocalyx of the endothelial component of neuronal vascular units, variations in expression of some genes and levels of the encoding molecules by the action of microRNAs (miRNAs), or other epigenetic factors and distinctive transcriptional factors, as well as the role of autophagy, ferroptosis, sex differences, and modifications in the circadian cycle. Such mechanisms can add significantly to understanding the complex etiological puzzle of neuroinflammation and ND. In addition, they could represent biomarkers and targets of ND, which is increasing in the elderly.