The gut microbiota plays a vital role in various physical and physiological processes, including immune system regulation, neurotransmitter production, inflammatory response modulation, and the inhibition of pathogenic organisms. An imbalance in the microbial community, known as dysbiosis, has been associated with numerous health issues. Biological influences, health behaviors, socioeconomic determinants, and nutritional status can disrupt this balance. Objective: To evaluate the differences in the gut microbiota composition in medical students according to fiber intake, ultra-processed food (UPF) consumption, sex, body mass index, and socioeconomic status. Methods: A cross-sectional study was conducted with 91 medical students, and 82 fecal samples were analyzed. Sociodemographic and dietary data were collected via questionnaires, UPF consumption was assessed using the NOVA classification, and trained nutritionists performed anthropometry. DNA extraction and 16S rRNA sequencing were performed for the microbial analysis. Bioinformatics and statistical tests included the Dunn and Kruskal–Wallis tests, a PCoA analysis, PERMANOVA, ANOVA, Spearman’s rank correlation, and alpha and beta diversity metrics. Results: Dietary fiber intake strongly influences gut microbiota composition. Lower fiber intake was associated with a higher prevalence of Parabacteroides and Muribaculaceae. Prevotella was more prevalent in individuals with lower UPF intake, while Phascolarctobacterium was prevalent in those with higher UPF consumption. Significant differences were associated with sex and UPF consumption but not BMI or SES. Women consumed more UPF, which correlated with distinct gut microbiota profiles. Conclusions: This study highlights the significant impact of diet, particularly fiber intake and UPF, on gut microbiota composition, emphasizing the importance of dietary habits in maintaining gut health.

Introduction: Compared to the general population, medical students are at greater risk of suffering from mental health problems, which can also affect their academic performance and professional future. Objectives: To evaluate the factors associated with depression, anxiety, and stress in medical students in Mexico. Methods: This was a cross-sectional study. A self-administered questionnaire was used to obtain sociodemographic, behavioral, and grade point average data, including the Depression, Anxiety, and Stress Scale-21 (DASS-21) screening instrument. Analysis: Measures of central tendency, dispersion, frequency, and proportion were used. The Wilcoxon rank-sum and immediate proportions tests were used to determine differences between the sexes, and the chi-square and Fisher’s exact tests were used between the scholar years. Logistic and linear regression models were performed to evaluate factors associated with depression, stress, and anxiety. Results: Depression affected 49% of students and was more common during the third year (60.1%). Anxiety was found in 66.1% of students and was also more common in third year (74.7%). Stress affected 73.2% of students, with greater severity and frequency in women. Low perception of social support and adverse childhood experiences were found to be associated with increased risk of depression, anxiety, and stress. However, in all cases, physical activity was found to be a protective factor. Conclusions: Studying mental health in medical students in Mexico is crucial to improving their well-being and academic performance, preventing burnout, and optimizing medical care. Adapting interventions to local and cultural factors can strengthen the health system and support the training of better professionals.

Background: Inconsistent epidemiological evidence between uric acid (UA) and bone mineral density (BMD) has been observed. Therefore, we evaluated the association between UA and BMD in Mexican adults. Methods: This analysis was conducted on 1423 participants from the Health Workers Cohort Study. We explored cross-sectional associations using linear regression and longitudinal associations using fixed-effects linear regression by sex and age groups (<45 and ≥45 years). Results: In females <45 years old, the cross-sectional analysis showed that UA levels were positively associated with total hip BMD. However, in the longitudinal analysis, we observed a negative association with the femoral neck and lumbar spine BMD. In contrast, in males <45 years old, we found an increase in total hip and femoral neck BMD in the groups with high levels of UA in the longitudinal association. On the other hand, in females ≥45 years old, we observed a longitudinal association between UA and loss of BMD at different sites. We did not observe an association between UA levels and BMD in males ≥45 years old. Conclusions: Our results suggest higher serum UA levels are associated with low BMD at different skeletal sites in Mexican females. Further studies are needed to delineate the underlying mechanisms behind this observation.

Background: Depression is a significant global mental health concern, especially among medical students. This study combines two components: (1) a cross-sectional assessment of depression and related psychological and demographic factors among students at “Dunărea de Jos” University of Galați, and (2) a systematic review and meta-analysis of published Romanian studies on depression in medical students. Methods: For the cross-sectional component, 495 students (Years I–III) completed online questionnaires assessing depressive symptoms (PHQ-9), personality traits, procrastination, and sociodemographic factors. In the systematic review, studies from PubMed and Web of Science were synthesized following PRISMA guidelines, with prevalence data being pooled via random-effects meta-analysis. Results: In the Galați sample, 34.0% of students had clinically significant depressive symptoms (PHQ-9 ≥ 10). Depression was associated with female gender, being in the third year of study, low social support, high neuroticism, and procrastination. The meta-analysis (six studies, N = 1546) yielded a pooled national prevalence of 19.99% (95% CI: 18.24–21.73%). Conclusions: Depression is highly prevalent among Romanian medical students, particularly in Galați. The findings support the need for targeted mental health interventions in Romanian universities. Registration: This systematic review has been registered in the Prospero database (registration number CRD420251056873).