Claudia Muñoz-Yáñez

Gut microbiota is shaped by interactions among diet, host characteristics, and microbial colonisation. This exploratory cross-sectional study examined associations between a dietary gradient, Blastocystis colonisation, and gut microbiota in 41 university students, seven (17.1%) of whom were colonised with Blastocystis. Dietary intake was assessed using a validated food frequency questionnaire, and a diet-ratio was derived from the relative energy contribution of industrialised and non-industrialised foods. Gut microbiota was characterised by 16S rRNA gene sequencing. The multivariable model including diet-ratio, age, and body mass index was associated with microbiota structure in the primary genus-level analysis (PERMANOVA: R² = 0.090, p = 0.041), although this association was attenuated after adjustment for abdominal pain and was not retained using the de novo DADA2 ASV table. Blastocystis colonisation was not associated with overall microbiota composition but was associated with greater alpha diversity (Shannon: p = 0.033; Gini–Simpson: p = 0.043). These alpha-diversity associations remained statistically significant after additional adjustment for abdominal pain and genus-level rarefaction, although they were less consistent in other sensitivity analyses. Genus-level associations with the dietary gradient did not remain significant after false discovery rate correction. No statistically significant diet-ratio × Blastocystis interaction was detected, although the small number of colonised participants limited assessment of effect modification. Overall, these findings suggest that dietary and Blastocystis-related associations may involve different ecological dimensions of the gut microbiota and warrant confirmation in larger studies.

Diet and gut microbiota are significant determinants of host health, but how dietary quality modulates gut microbiota in Blastocystis-colonised individuals remains underexplored. We studied two contrasting cohorts: university students (FACSA, n = 46) and institutionalised children with their caregivers (PAVILA, n = 37), representing distinct dietary and sociodemographic contexts. Eight participants from each cohort tested positive for Blastocystis; however, two PAVILA samples could not be sequenced, resulting in a final microbiota subcohort of 14 individuals (FACSA n = 8, PAVILA n = 6). Dietary quality was assessed using the Healthy Eating Index-2020 (HEI-2020), and faecal microbiota was characterised through 16S rRNA sequencing. Alpha and beta diversity were analysed, and genus-level transformed data were further evaluated using permutational multivariate analysis of variance (PERMANOVA), principal coordinates analysis (PCoA), and distance-based redundancy analysis (db-RDA). The FACSA cohort exhibited higher microbial richness and diversity (Shannon and Simpson indexes, p < 0.01) compared to PAVILA, with marked differences in microbial composition (PERMANOVA R² = 0.39, p = 0.002). Total diet quality correlated with microbial structure (R² = 0.26, p = 0.016), with protein (R² = 0.23, p = 0.017) and vegetable components (R² = 0.17, p = 0.044) as primary contributors. Multivariate analysis showed that higher protein and vegetable intakes were associated with genera such as Sellimonas, Murimonas, Alistipes, and Desulfovibrio (FACSA group). In contrast, Hydrogenoanaerobacterium, V9D2013_group, and Haemophilus were linked to lower-quality diets (PAVILA group). Our results indicate that diet quality significantly influences gut microbiota composition in individuals colonised by Blastocystis, underscoring its potential as a target for nutritional interventions in vulnerable populations.

Diet and gut microbiota are key determinants of host health, but their interaction in Blastocystis-colonised individuals remains poorly understood. We evaluated the rela-tionship between diet quality, faecal microbial diversity, and Blastocystis colonisation in two cohorts: university students (FACSA) and institutionalised children with their caregivers (PAVILA), all Blastocystis-positive subjects. We assessed diet quality using the Healthy Eating Index-2020 (HEI-2020), and we characterised faecal microbiota by 16S rRNA sequencing. Alpha and beta diversity were analysed, and genus-level trans-formed data were further evaluated using PERMANOVA, PCoA, and db-RDA. The FACSA cohort presented higher microbial richness and diversity (Shannon and Simpson indexes) than PAVILA (p < 0.01), and microbial composition differed signifi-cantly between cohorts (PERMANOVA R² = 0.39, p = 0.002). Total diet quality was as-sociated with microbial structure (R² = 0.26, p = 0.016), with protein (R² = 0.23, p = 0.017) and vegetable (R² = 0.17, p = 0.044) components being the main contributors. Multivariate analysis showed higher protein and vegetable intakes were associated with genera such as Sellimonas, Murimonas, Alistipes and Desulfovibrio (FACSA group). In contrast, Hydrogenoanaerobacterium, V9D2013_group and Haemophilus were related to lower-quality diets (PAVILA group). Despite universal colonisation by Blastocystis, differences in microbial diversity and structure reflect a modulating effect of diet con-ditioned by the sociodemographic environment. These findings suggest the relevance of dietary quality as a modulator of the gut microbiota in populations colonised by Blastocystis and may guide future nutritional interventions in vulnerable groups.

Blastocystis is a very common gastrointestinal protozoan globally distributed; it colonizes humans and non-humans, and in some communities, it reaches prevalences of up to 100%. Blastocystis is transmitted through the fecal-oral route, contaminated food and water, and close contact with animals. There are 34 known subtypes of Blastocystis, and subtypes 1 to 4 (ST1ST4) are the most common in humans. It should be remembered that its pathogenicity is controversial since some studies have shown that Blastocystis is more prevalent in healthy individuals; who have greater diversity and richness of the intestinal microbiota; other studies suggest that Blastocystis infections occur in individuals with intestinal dysbiosis. In America and Africa, a high incidence of ST1 and ST2 is observed in rural areas. Recent data indicate that Blastocystis is linked with specific gut microbiota profiles and health indicators. Convincing information and tools that distinguish asymptomatic colonization from infection in children have yet to be demonstrated. Although this protozoan can cause disease under certain circumstances, but the attention of Blastocystis may change, as the frequency of Blastocystis subtypes in children may vary depending on the geographic area and local health conditions.

El síndrome metabólico (SM) es conjunto de enfermedades crónicas caracterizado por cambios bioquímicos e inflamatorios con riesgo aumentado de morbimortalidad. El objetivo fue describir los marcadores de inflamación, el riesgo cardiovascular y el consumo dietético en sujetos con SM. Se incluyeron para análisis transversal sujetos con SM de dos Unidades Médicas de Atención Especializada en Enfermedades Crónicas (UNEME-EC) de la región Laguna del estado de Durango. El 100% de los sujetos presentaron obesidad abdominal, 34.4% exhibió un riesgo cardiovascular intermedio-alto, niveles de IPL e INL por encima de la media en el 49% y 45.2% respectivamente. El consumo dietético fue elevado en calorías, cereales y alimentos de origen animal y bajo en fibra. El riesgo elevado de morbimortalidad a 10 años encontrado en estos sujetos requiere un mayor control y la evaluación de factores asociados al descontrol metabólico e inflamatorio que presentan.

Los desórdenes metabólicos se caracterizan por inflamación crónica de bajo grado. Diversos marcadores inflamatorios, aterogénicos y adipocinas se asocian con síndrome metabólico, incrementando la aterosclerosis y la morbi-mortalidad cardiovascular. Objetivo: describir el riesgo cardiovascular (RCV), la adiposidad, los marcadores inflamatorios y aterogénicos en pacientes mexicanos con enfermedad metabólica del Estado de Durango, México. En todos los participantes se realizó antropometría, determinación bioquímica y lipídica, biometría hemática y adipocinas séricas. Se calcularon adiposidad, índices aterogénicos e inflamatorios y RCV. La grasa visceral y corporal se clasificó como alta y muy alta, respectivamente; 88.3% tenían síndrome metabólico. El perfil lipídico, los marcadores bioquímicos, la adiponectina, el índice aterogénico y el RCV fueron mayores a mayor número de comorbilidades. Conclusión: las metas terapéuticas deben enfocarse enérgicamente a pacientes con mayor número de anormalidades metabólicas para disminuir su RCV y mortalidad.

The role played by Blastocystis in humans has been a subject of discussion due to its intestinal effects and modifications in the intestinal microbiota. We aimed to analyze the relationship between Blastocystis subtypes ST1-4 and 7, the Firmicutes to Bacteroidetes ratio (F/B ratio) of fecal microbiota, and chronic stress in university students. This study had a cross-sectional design with a sample of 202 students. We analyzed fecal and hair samples, and stress inventories were applied to the students. The results showed a frequency of Blastocystis-colonized students of 52.97%. Regarding fecal microbiota, a median RAU of 0.801 for Firmicutes and 0.82 of Bacteroidetes were obtained, with an F/B ratio of 0.83. A low F/B ratio (66.04%) was more frequent in Blastocystis-colonized students, whereas a high F/B ratio (68.09%) (p = < 0.0001) was found in the Blastocystis-non-colonized. Only Blastocystis ST3 did not significantly correlate with a low F/B ratio (p = 0.290). The ST4 was associated with lower values of cortisol (p = 0.030), psychological stress (p = 0.040), and lower frequency of constipation (p = 0.010). Only two students with the ST1 had abdominal pain (p = 0.007). Our results suggest that colonization by Blastocystis subtypes can modify the intestinal microbiota due to a decreased ratio between the two most representative phyla (F/B). Also, the results of this study show that ST4 colonization is related to a lower level of chronic stress. Graphical abstract

Background: Blastocystis is a typical anaerobic colon protist in humans with controversial pathogenicity and has relation with alterations in the intestinal microbiota composition (dysbiosis), whose eventual indicator is the Firmicutes/Bacteroidetes ratio (F/B ratio); this indicator is also linked to complications such as diabetes, obesity, or inflammatory bowel disease. The present study investigated the prevalence of Blastocystis and its association with Firmicutes/Bacteroidetes ratio in healthy and metabolic diseased subjects. Methods: Fecal and blood samples were collected consecutively from 200 healthy subjects and 84 subjects with metabolic disease; Blastocystis and its most frequent subtypes were identified by end-point PCR and the two most representative phyla of the intestinal microbiota Firmicutes and Bacteroidetes by real-time PCR. Results: The prevalence of Blastocystis in healthy subjects was 47.0, and 65.48% in subjects with metabolic disease; the most prevalent subtype in the total population was ST3 (28.38%), followed by ST1 (14.86%), ST4, ST5, and ST7 (each one of them with 14.19% respectively), and finally ST2 (8.78%). The low F/B ratio was associated with the prevalence of Blastocystis in the two cohorts FACSA (OR = 3.78 p < 0.05) and UNEME (OR = 4.29 p < 0.05). Regarding the subtype level, an association between the FACSA cohort ST1 and ST7 with low Firmicutes/Bacteroidetes ratio was found (OR = 3.99 and 5.44 p < 0.05, respectively). Conclusions: The evident predatory role of Blastocystis over Firmicutes phylum was observed in both cohorts since the abundance of bacterial group’s Bacteroidetes increases in the groups colonized by this eukaryote and, therefore, may have a beneficial effect.

Introducción. La obesidad y su comorbilidad son de las principales causas de muerte en México, es una enfermedad multifactorial, en la que se ha visto además la participación de un agente infeccioso. Ad36 se ha asociado con obesidad, pero paradójicamente también con niveles más bajos de glucosa, colesterol y triglicéridos, sin embargo, existe controversia en diferentes poblaciones. Objetivo. Evaluar la asociación de anticuerpos antiAd36 con variables antropométricas y bioquímicas. Material y métodos. Estudio transversal en 299 niños mexicanos mestizos en edad escolar (6 a 12 años). Se obtuvieron mediciones antropométricas de altura, peso corporal, circunferencia de la cintura, grosor del pliegue cutáneo del tríceps, se calculó índice de masa corporal (IMC) y relación cintura/ altura. Las variables bioquímicas incluyeron niveles séricos de glucosa, triglicéridos, colesterol total, lipoproteínas de alta densidad y lipoproteínas de baja densidad. Se utilizó un ensayo inmunoabsorbente ligado a enzimas (ELISA) para determinar los anticuerpos contra Ad36 en las muestras de suero. Resultados. Los anticuerpos anti-Ad36 se asociaron con niveles más bajos de colesterol sérico total (β = -0.133, p = 0.021) y LDL (β = -0.166, p = 0.004), y con niveles más altos de HDL (β = 0.120, p = 0.037), pero no con obesidad. Conclusión. En resumen, la exposición previa a Ad36 se asoció con un mejor perfil lipídico en niños mexicanos, independientemente de la obesidadBackground. Obesity and its comorbidities are one of the main causes of death in Mexico; it is a multifactorial disease, in which the participation of an infectious agent has been evaluated. Ad36 is associated with obesity, but paradoxically also with lower levels of glucose, cholesterol and triglycerides; however, there is controversy in different populations. Objective. To evaluate the association of antibodies against Ad36 with anthropometric and biochemical variables. Material and Methods. Cross-sectional study in 299 Mexican-mestizo children of elementary schools (6-12 years old). Anthropometric measurements of height, body weight, waist circumference, thickness of the triceps skin fold were obtained; body mass index (BMI) and waist / height ratio were calculated. Biochemical variables included serum glucose, triglycerides, total cholesterol, high-density lipoproteins, and low-density lipoproteins. An enzyme-linked immunosorbent assay (ELISA) was used to determine antibodies against Ad36 in serum samples. Results. Anti-Ad36 antibodies were associated with lower levels of total serum cholesterol (β = -0.133, p = 0.021) and LDL (β = -0.166, p = 0.004), and with higher levels of HDL (β = 0.120, p = 0.037), but not with obesity. Conclusion. Previous exposure to Ad36 was associated with a better lipid profile in Mexican children, regardless of obesity