Blood orange juice is an important source of
flavanones and
anthocyanins, mainly
hesperidin,
narirutin, and cyanidin-3-O-glucoside. The benefits of these bioactive compounds have been reported, but the mechanistic details behind their
biological effects are not well established. This study investigated the effects of Moro orange (Citrus sinensis L. Osbeck) juice (MOJ) on gut microbiota composition and cardiometabolic
biomarkers in
overweight women. In this study, 12
overweight women (BMI from 25.0 to 29.9 kg/m2), aged 18-37 years, consumed 500 mL of MOJ every day for 4 weeks. We assessed the gut microbiota composition, levels of
short-chain fatty acids (SCFAs), cardiometabolic
biomarkers, and
insulin resistance (HOMA-IR) at baseline and after 2 weeks and 4 weeks of MOJ intake. The results suggested that MOJ intake affected the abundance of specific operational taxonomic units (OTUs) of the gut microbiota but did not significantly alter the diversity and general composition of the gut microbiota. However, MOJ intake increased the production of SCFAs, especially propionic and
isobutyric acids, and significantly improved cardiometabolic
biomarkers such as blood pressure and plasma
VCAM-1 levels in the
overweight women. Additionally, we observed significant associations between gut microbiota OTUs belonging to the Bacteroidetes phyla and Prevotella 9 genera and the cardiometabolic
biomarkers. Furthermore, MOJ reduced fasting
glucose and
insulin levels and HOMA-IR values, thereby enhancing
insulin sensitivity in the
insulin-resistant
overweight women. Finally, we highlighted the importance of orange juice intake duration because some beneficial changes such as blood pressure improvements were evident at the 2-week time interval of the intervention, but other changes became significant only at the 4-week interval of MOJ intake. In conclusion, our study demonstrated that changes in specific OTUs of the gut microbiota in response to MOJ intake were associated with significant improvements in some cardiometabolic
biomarkers and SCFA levels in
overweight women with
insulin resistance.