Mediterranean-like diet may modulate acute inflammation in Wistar rats

INTRODUCTION AND OBJECTIVES

Mediterranean Diet (MD) is very rich in bioactive components such as fiber and polyphenols. Some of these have demonstrated its immunomodulatory effect and its activity in inflammation models.

The objective of this study was to evaluate the impact of a diet rich in polyphenols and fibers on the animal's innate immunity.

MATERIAL AND METHODS

The intervention was performed in two groups of 7-week-old rats, one receiving a experimental MD-like diet (MD) and the other serving as the reference diet (REF). Animals were followed during nine weeks. The feed and water consumption were monitored three times a week, and fecal samples were collected weekly to assess pH and humidity content. At the end of the study, a local inflammation was induced by injecting the rat's paw with carragenine. The inflammatory process was monitored for six hours by pletismometry. Finally, the rats were euthanized, and tissue samples were obtained for further analysis.

RESULTS AND DISCUSSION

After 6 hours of monitoring, a statistically significant decrease in the paw volume of rats from the MD-like diet group (MD) was observed compared to the reference group (REF). The immunoglobulin profile, the faecal pH and humidity were also affected. These results could be correlated with the anti-inflammatory effect of both fibers and polyphenols. However, more studies are necessary to evaluate the specific mechanisms of this process to gain a better understanding.

CONCLUSION

In conclusion, a Mediterranean diet, which is characterized by being enriched in polyphenols and fiber, may have an anti-inflammatory effect, and can also modulate immunity. Changes at epigenetic level and on microbiota composition could be involved.

ACKNOWLEDGMENTS

The authors thank the project PID2020-119602RB-I00 funded by the MCIN/AEI /10.13039/501100011033 and the INSA Maria de Maeztu Unit of Excellence grant (CEX2021-001234-M) funded by MICIN/AEI/FEDER, UE.