Recently, an association between dysbiosis of the gut microbiota (GMB) and the development of several diseases, such as Alzheimer’s disease (AD), has been proposed. Dysbiosis involves changes in microbial diversity influenced by environmental factors, like diet or lifestyle. In this study, we investigated the role of GMB parameters in Spanish AD patients, assessing the impact of adherence to the Mediterranean lifestyle (ML), as well as to characterize these parameters in relation to neuropsychological, neuropsychiatric, emotional, and functionality parameters. A case–control study was conducted to investigate the association between the composition of the GMB and cognitive, emotional, neuropsychiatric, and functionality status in Spanish AD patients, along with a shotgun metagenomics approach. Richness and alpha-diversity were significantly lower in the AD group compared to the controls. PERMANOVA and ANOSIM tests of Bray–Curtis dissimilarity, Aitchison distance, and Jaccard similarity did not showed significant differences in beta-diversity between the two groups. Moreover, associations between various phyla of the AD group and orientation performance, food consumption, and activities of daily living were identified. Dysbiosis observed in Spanish AD patients is characterized by reductions in richness and alpha-diversity, alongside alterations in GMB composition, which may be linked to adherence to the ML and cognitive and functionality symptoms.

: Dementia is a syndrome resulting from chronic or progressive brain disease. Around 40% of worldwide dementia can be prevented or delayed by modifying 12 risk factors: low educational attainment in early life, mid-life hypertension, mid-life obesity, hearing loss, traumatic brain injury, excessive alcohol consumption, smoking, depression, physical inactivity, social isolation, diabetes mellitus, and air pollution. There is growing evidence that gastrointestinal tract microbiota may significantly contribute to dementia pathogenesis. In particular, gut dysbiosis can trigger metabolic diseases and the progression of low-grade systemic inflammation, being involved in much of the major modifiable risk factors. In this review, we focus on studies that have evaluated the association between modifiable risk factors for dementia and the role of gut microbiota. We also suggest clinical implications for researchers in dementia-gut microbiota related fields.

Although research in recent years has revealed widespread discrimination against transgender people, few studies have addressed the attitudes of those who discriminate. In fact, although studies report that bullying is very common in adolescence, little is known about the attitudes of adolescents towards transgender people. This study aimed to determine the roles of social reputation, family socialisation, the big five personality traits and aggressiveness in transphobia and gender bashing among adolescents. The sample consisted of 479 students (50.1% boys) aged 14–19 (M = 15.04; SD = 1.06). The results revealed that transphobia and gender bashing were significantly related to the study variables. Specifically, the results showed that transphobia is largely predicted by variables of the type related to affect and personality, while gender bashing is largely related to variables of a social and reputational nature. Similarly, differences were found between genders, with boys having significantly higher scores than girls for transphobia and gender bashing, as well as specificity of predictors. The implications of these findings are discussed.

Parkinson's disease (PD) and dementia with Lewy bodies (DLB) are related α-synucleinopathies that share Lewy pathology, but they differ clinically. Increasing evidence links gut microbiota (GMB) dysbiosis and microbially derived metabolites to Parkinsonian disorders yet reported associations remain heterogeneous across cohorts and the Lewy body dementia syndromes are comparatively under characterized. This study integrated clinical characterization and GMB profiling in Parkinson's disease dementia (PDD), DLB, and healthy controls (HC) to identify shared and syndrome specific features, and to relate these patterns to cognitive, neuropsychiatric, and functional outcomes. The present cross-sectional case-control study in Spain included 76 adults aged 60 to 85 years (HC = 38, PDD = 27, DLB = 11). Stool samples underwent shotgun metagenomic sequencing, with species-level taxonomic profiling using Kraken2. Community diversity was assessed using observed species and Chao1 richness, Shannon alpha diversity, and Bray-Curtis dissimilarity for beta diversity. LEfSe and multivariate linear modeling with MaAsLin2 were performed to identify GMB species associated with PDD and DLB and their clinical correlates. PDD showed higher richness compared with HC. Shannon alpha diversity did not differ between groups. Bray-Curtis differed by separation of HC from both PDD and DLB, with no significant difference between Lewy body dementia syndromes. LEfSe identified 19 significantly differential taxa. Furthermore, several taxa showed significant multivariable associations with clinical outcomes. PDD and DLB shared a broadly similar GMB alteration away from HC, with multivariable associations between several taxa and clinical outcomes. Longitudinal and functional studies are needed to clarify causality and biomarker potential.