Background/Objectives: The effects of geographical origin, alongside age, diet, and drug treatments, on the gut microbiota have not been thoroughly analyzed in African countries. Furthermore, eukaryotic components, including Blastocystis, the most common intestinal protozoan worldwide, require further investigation. This study compares the gut microbiota of Italian subjects with that of two African groups to examine the influence of dietary patterns and the effects of Blastocystis presence and subtypes. Methods: Three cohorts of healthy subjects (Italians residing in Rome, Africans residing in the Côte d’Ivoire, and Africans living in Italy) were compared by sequencing the V3-V4 hypervariable regions of the 16S rDNA gene. Taxa abundance and associations with typical West African and Italian foods were determined using DESeq2. Co-abundant genera were identified with a weighted correlation network analysis (WGCNA). Blastocystis subtypes were determined and correlated with the microbial composition in the three groups. Results: Distinct microbial taxa were associated with specific foods, including palm oil, Cube Maggi, sunflower oil, and olive oil. A Mediterranean diet consumed for over two years did not alter the abundance of Faecalibacterium and Dorea in the Africans living in Italy compared with Africans living in Côte d’Ivoire, whereas differences were observed in the abundance of some Prevotella-9, Bacteroides, and Lachnospiraceae OTUs. Significant associations were identified between palm oil and Subdoligranulum, Cube Maggi and Dorea, sunflower oil and the Ruminococcus torques group, and olive oil and Faecalibacterium. Concerning Blastocystis, alpha and beta diversity analysis showed a significant separation between carriers and non-carriers. Conclusions: This study provides the first comparative analysis of gut microbiota composition between individuals from Côte d’Ivoire and Italians focusing on the influence of distinct dietary patterns.

Gut microbiota (GM) alterations and related metabolic outputs have been implicated in metabolic syndrome (MetS) and early cardiometabolic risk. However, the associations between GM alterations and MetS, and their relationship with the marked interindividual variability in cardiovascular risk, remain incompletely defined. We conducted a cross-sectional study in individuals with obesity (n = 176) to evaluate associations between GM features and MetS clinical traits using 16S amplicon profiling data. Prevalence of individual MetS traits was 37.4% for hyperglycemia, 23.4% for hypertriglyceridemia, 54.0% for hypertension, and 52.1% for low HDL cholesterol, with 51.1% of participants meeting criteria for MetS overall. Comparative analysis of 16S rRNA amplicon sequencing data identified a shared gut microbial signature comprising 45 ASVs across MetS clinical components. Members of Prevotellaceae and Ruminococcaceae were consistently reduced in MetS, whereas Veillonella and Streptococcus were enriched. Reduced microbial alpha diversity was observed in individuals with MetS. PICRUSt2-based functional inference indicated lower representation of pathways related to complex carbohydrate utilization and short-chain fatty acid (SCFA) metabolism in MetS-positive individuals. Our results, derived from two independent datasets, indicate that MetS is associated with a depletion of bacterial taxa involved in complex carbohydrate metabolism and SCFA production.