Probiotic-Mediated Vitamin D Supplementation Improves the Gut Microbiota and Vitamin D Receptor Composition in Obese Rats

Kılınç G. E., Söğüt M.

FOOD SCIENCE & NUTRITION, vol.14, no.6, 2026 (SCI-Expanded, Scopus)

  • Publication Type: Article / Article
  • Volume: 14 Issue: 6
  • Publication Date: 2026
  • Doi Number: 10.1002/fsn3.71967
  • Journal Name: FOOD SCIENCE & NUTRITION
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Food Science & Technology Abstracts, Greenfile, Academic Search Ultimate (EBSCO), Natural Science Collection (ProQuest), Health Research Premium Collection (ProQuest)
  • Keywords: gut microbiota, obesity, probiotics, vitamin D, vitamin D receptor
  • Ondokuz Mayıs University Affiliated: Yes

Abstract

Obesity is a complex disorder affecting metabolism and immunity, with gut microbiota and vitamin D metabolism playing key roles. This study aimed to evaluate the impact of vitamin D supplementation and probiotics on the vitamin D receptor (VDR) levels and the gut microbiota of rats given a high-fat diet as an experimental model of obesity. In this study, experimental obese rat models were used to assess the impact of vitamin D and probiotic supplements on lipid profiles, inflammation, obesity, diabetes, VDR, and gut microbiota. 24 Wistar rats (4-6 weeks) were divided into four groups: control, high-fat diet, high-fat diet with probiotic supplementation (HFD + P), and high-fat diet with probiotic and vitamin D supplementation (HFD + P + VD). Blood and fecal samples were collected from rats for analysis. Changes in BMI values, initial and final weights, and weight changes across all groups were found (p = 0.018, p = 0.006, p = 0.023). HFD + P and HFD + P + VD showed lower levels of insulin, CRP, triglycerides, IL-6, HOMA-IR, and leptin. Supplementing probiotics and vitamin D reduced the phylum Bacteroidetes while increasing the phyla Proteobacteria, Firmicutes, and Actinobacteria. The findings suggest that probiotics combined with vitamin D supplementation may be a promising approach for supporting the management of obesity-related metabolic disorders and microbiota. Furthermore, probiotics may enhance vitamin D's effectiveness by inducing VDR expression.