In this study, we investigate the associations between Vitamin D Receptor (VDR) polymorphisms and gut microbiota in a sample of the Spanish population. The exploration of these connections is of great importance as VDR plays a crucial role in mediating the biological effects of vitamin D, and the gut microbiota is known to influence various aspects of human health. By analyzing genetic variations in the VDR gene and their potential impact on gut microbial composition, we aim to shed light on the interplay between these factors in the context of the Spanish population.
We recruited a total of 87 healthy participants (57 men and 30 women), aged between 18 and 48 years. To ensure homogeneity and eliminate potential confounding factors, exclusion criteria were applied, including any form of pathology within six months prior to the study, previous gastrointestinal surgery, antibiotics intake within three months prior to the study, smoking, usage of prebiotics, probiotics, or nutritional supplements, being vegetarian or vegan, and pregnancy or lactation. All participants were of Caucasian ethnicity and residing in Spain.
To test if we were having a homogeneous sample representative of the Spanish population, conditions for checking Hardy-Weinberg equilibrium for the VDR (rs2731236). Allelic discrimination analysis was performed with predesigned Applied Biosystems TaqMan® SNP Genotyping Assays: and the StepOnePlus Real-Time PCR system from ThermoFisher Scientific. The SNP exact test for Hardy-Weinberg equilibrium was conducted for the entire population and separately for males and females. The whole population (p-value=0.071), as well as the male (p-value=0.52) and female (p-value=0.24) subgroups, were all in Hardy-Weinberg equilibrium for the studied SNP.
The samples were analyzed using a metataxonomic approach based on the V3-V4 regions for sequencing. Anthropometric measures, as well as dietary habits, were also studied. Statistical analysis was carried out using QIIME2 v2019.10, SPSS software v26.0 (SPSS, Chicago, IL), and the R statistical package v4.1.1.
No differences were found in both body composition parameters and diet.
LEfSe (Linear Discriminant Analysis Effect Size) statistical analysis shows that the GG genotype is enriched in the g__Solobacterium whilst the AA genotype was enriched in g__Victivallaceae g__Moryella g__Enterococcus f__Enterococcaceae p__Desulfobacterota c__Desulfovibrionia o__Desulfovibrionales f__Desulfovibrionaceae f__Selenomonadaceae and f__Ruminococcaceae.
These findings suggest that genetic variations may influence gut microbiota composition, leading to different associations with specific microbial taxa. Further investigations are warranted to elucidate the potential impact of these microbial variations on human health and disease.
