Effect of Mediterranean Diet Enriched in High Quality Extra Virgin Olive Oil on Oxidative Stress, Inflammation and Gut Microbiota in Obese and Normal Weight Adult Subjects

Abstract

Introduction: The Mediterranean Diet (MD) is useful in the prevention of overweight, obesity and metabolic disease. High Quality-Extra Virgin Olive Oil (HQ-EVOO), an essential component of this diet, exerts protective effects against chronic diseases. Gut Microbiota (GM), recognized as a key factor in driving metabolic activities, is involved in the regulation of host immunity. Lactic Acid Bacteria (LAB) and their probio-active cellular substances produce beneficial effects in the gastrointestinal tract.Materials and Methods: Eighteen overweight/obese subjects (cases, BMI ≥25 kg/m2) and 18 normal weight controls (BMI 18.5–24.9 kg/m2) were fed with MD enriched with 40 g/die HQ-EVOO for three months. Feces and blood samples were collected at time 0 (T0) and after three months (T1) for LAB composition, oxidative stress, metabolic and inflammation parameter determinations.Results: Myeloperoxidase and 8-hydroxy-2-deoxyguanosine, markers of inflammation and oxidative stress, were significantly decreased after MD rich in HQ-EVOO both in controls and in cases. Proinflammatory cytokines levels were significantly decreased in cases in comparison to controls, while IL-10 and adiponectin were significantly increased in cases. LAB’s rpoB copies/ng of DNA increased 55.6 folds in cases compared to their baseline after MD rich in HQ-EVOO. MD rich in HQ-EVOO increased adiponectin and IL-10 concentration in overweight/obese subjects and decreased oxidative stress and inflammation parameters and at the same time, increased LAB number in GM.Discussion: Our results indicate that MD rich in HQ-EVOO induces an increase of LAB in GM and could have a potential role in the prevention of inflammation.Clinical Trial Registration: , identifier NCT03441802.

Mediterranean Diet, Physical Activity and Gut Microbiome Composition: A Cross-Sectional Study among Healthy Young Italian Adults

“…Nevertheless, at the genus level, several important differences were highlighted in our sample. In particular, as previously reported, the Streptococcus genus was highly abundant among overweight/obese participants, so as the Dorea and Dialister, which were also mainly represented among low-active individuals [37,38]. Interestingly, Dorea and Dialister were found to be related with insulin secretion and fasting blood glucose, suggesting their role in type 2 diabetes development in overweight-obese individuals [38].…”

“…Lachnospira was more represented among individuals with higher adherence to the MD, while Paraprevotella was more represented in those with lower MD scores. The literature reports that vegetable-based diets tend to correlate with the amount of short-chain fatty acids (SCFA), which are produced by gut bacteria through dietary fiber fermentation and have fundamental effects on the immunity, metabolism, and inflammation processes of the host [38]. Lachnospira among Firmicutes, so as Prevotella among Bacteroidetes, seem to be involved in the fermentation of fibers, leading to a higher SCFA production.…”

Daily Use of Extra Virgin Olive Oil with High Oleocanthal Concentration Reduced Body Weight, Waist Circumference, Alanine Transaminase, Inflammatory Cytokines and Hepatic Steatosis in Subjects with the Metabolic Syndrome: A 2-Month Intervention Study

“…However, one of the main distinctive components of the MD is EVOO, representing the main source of dietary fat and polyphenols [ 31 , 32 ], the latter being potent inhibitors of reactive oxygen species and associated with a reduced risk for CVD and several types of cancer [ 2 , 33 , 34 , 35 , 36 ]. Several studies confirmed the beneficial effects of polyphenols in olive oil on heart disease risk factors and oxidative damage [ 37 , 38 , 39 , 40 ]. In addition, EVOO has been widely studied for its favorable effects on plasma concentrations of low-density lipoprotein cholesterol (LDL-C) and total cholesterol [ 33 , 39 , 41 , 42 , 43 ], as well as on blood pressure [ 43 , 44 , 45 ].…”

“…Interestingly, a preclinical study has shown that an EVOO-enriched diet had the best results on the musculoskeletal system in an osteoarthritis rat model, including decreased IL-6 expression [ 65 ]. On the other hand, an MD rich in high quality EVOO also significantly increases IL-10 levels [ 40 ]. By correlation analysis, we interestingly found an inverse association between changes in IL-6 and those in SFT max, which further highlights the concurrent effects of olive oil supplementation on anti-inflammatory cytokines and abdominal fat distribution.…”

Metabolomic Study to Evaluate the Transformations of Extra-Virgin Olive Oil’s Antioxidant Phytochemicals during In Vitro Gastrointestinal Digestion

“…EVOO has been widely studied because of its effects in preventing several metabolic diseases and pathologies, such as atherosclerosis, cardiovascular diseases, serum lipoprotein levels, oxidative stress, obesity, type 2 diabetes, inflammation and cancer [1][2][3][4][5]. Overall, the health-promoting effects of EVOO are mainly related to its inherent chemical composition, such as the fatty acid profile [6] rather than other "minor" components (nearly 2% of the total weight).…”