Linking serum vitamin D levels with gut microbiota after 1-year lifestyle intervention with Mediterranean diet in patients with obesity and metabolic syndrome: a nested cross-sectional and prospective study

ABSTRACT

Vitamin D, microbiota, and the Mediterranean diet (MedDiet) have been the focus of recent research due to their potential role in maintaining overall health. We hypothesize that MedDiet may alter the gut microbiota profile through changes in vitamin D levels. We aimed to investigate changes in gut microbiota and serum vitamin D levels after a MedDiet within a lifestyle intervention. The study included 91 patients with obesity and metabolic syndrome, who were categorized based on their serum vitamin D levels as having either optimal or low 25-hydroxyvitamin D [25(OH)D levels]. The profile of the gut microbiota was analyzed by the 16S rRNA sequencing, inferring its functionality through PICRUsT. Participants underwent a hypocaloric MedDiet and change in their lifestyle for 1 year, and the profile and functionality of their gut microbiota were evaluated by analyzing inter-individual differences in time. At baseline, gut microbiota profiles qualitatively differed between participants with Optimal or Low 25(OH)D levels [Unweighted (p = 0.016)]. Moreover, participants with Optimal 25(OH)D levels showed a higher gut microbiota diversity than those with Low 25(OH)D levels (p < 0.05). The differential analysis of abundance between the Low and Optimal 25(OH)D groups revealed differences in the levels of Bacteroides, Prevotella, and two Clostridiales features. After 1-year dietary intervention, both groups increased their 25(OH)D levels. Furthermore, both groups did not show significant differences in gut microbiota diversity, although the Low 25(OH)D group showed greater improvement in gut microbiota diversity by comparing at baseline and after dietary intervention (p < 0.05). Changes in specific bacterial taxa were observed within each group but did not differ significantly between the groups. Metabolic pathway analysis indicated differences in microbial functions between the groups (p < 0.05). These findings suggest that 25(OH)D status is associated with gut microbiota composition, diversity, and functionality, and lifestyle intervention can modulate both gut microbiota and 25(OH)D levels, potentially influencing metabolic pathways.

KEYWORDS:

• 25-hydroxyvitamin D
• obesity
• metabolic syndrome
• gut microbiota
• vitamin D
• MedDiet
• mediterranean diet

Acknowledgments

This study has been partially funded by Instituto de Salud Carlos III (ISCIII), and Junta de Andalucía, co-funded by the European Regional Development Fund, through the projects PI18/01160, PI21/01677, and UMA-FEDERJA-116. This study was supported by “Centro de Investigacion Biomédica en Red Fisiopatología de la Obesidad y Nutricion”, which is an initiative of the “Instituto de Salud Carlos III” (ISCIII) of Spain, co-funded by the European Union (CB06/03), a grant from ISCIII (PI18/01399, PI21/00633) and a grant from Consejeria Universidad, Investigacion e Innovacion Junta de Andalucia (PY20-01270). HB is supported by a predoctoral fellowship (“Plan Propio IBIMA 2020 A.1 Contratos predoctorales”, Ref.: predoc20_002) and by a “Sara Borrell” postdoctoral contract (CD22/00053) from the Instituto de Salud Carlos III - Madrid (Spain), “Financiado por la Unión Europea – NextGenerationEU” y mediante el Plan de Recuperación, Transformación y Resiliencia. PRL was supported by a “Sara Borrell” postdoctoral contract (CD19/00216) from the ISCIII-Madrid (Spain), cofunded by the Fondo Europeo de Desarrollo Regional-FEDER. IM-I was supported by a Miguel Servet II contract -CPII21-00013- Instituto de Salud Carlos III (ISCIII). M.M.G. was the recipient of the Nicolas Monardes Programme from the “Servicio Andaluz de Salud, Junta de Andalucia,” Spain (RC-0001-2018 and C-0029-2014).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contribution

HB and PRL designed research studies. FJT, IMI and MMG supervised the study. HB, PRL, JP, JL, conducted experiments. HB and IMI acquired data. HB and PRL wrote the manuscript. HB, PRL, and IMI analyzed data. All authors revised the manuscript.

Data availability statement

Due to the nature of this research, participants of this study did not agree for their data to be shared publicly, so supporting data is not available.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/19490976.2023.2249150

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

The work was supported by the Instituto de Salud Carlos III [CD22/00053]; Instituto de Salud Carlos III [CD19/00216]; Instituto de Salud Carlos III [PI18/01160, PI21/01677]; Instituto de Salud Carlos III [CPII21-00013]; Servicio Andaluz de Salud [RC-0001-2018, C-0029-2014].