Diet, Physical Exercise, and Gut Microbiota Modulation in Metabolic Syndrome: A Narrative Review

Area of Science:

• Gut Microbiota and Metabolism
• Cardiometabolic Health
• Lifestyle Interventions

Background:

• Metabolic syndrome (MetS) is a complex condition influenced by lifestyle, with the gut microbiota emerging as a key mediator.
• Diet and physical activity significantly impact gut microbial composition and function, influencing cardiometabolic health.

Purpose of the Study:

• To review and synthesize evidence on how physical exercise and dietary patterns (MedDiet, DASH, KD/VLCKD) affect the gut microbiota in MetS.
• To explore the implications of these changes for metabolic health and the gut microbiota-metabolism axis.

Main Methods:

• Qualitative narrative synthesis of human and animal studies (experimental, observational, interventional).
• Literature review focused on associations between exercise/dietary interventions and gut microbiota changes (diversity, taxa, metabolites) and cardiometabolic outcomes.
• Acknowledged heterogeneity in study populations, interventions, and methodologies.

Main Results:

• Moderate physical exercise consistently increased microbial diversity and SCFA-producing bacteria, improving insulin sensitivity and reducing inflammation.
• MedDiet and DASH promoted favorable microbiota profiles (e.g., increased *F. prausnitzii*, *A. muciniphila*, *Bifidobacterium*) and reduced harmful metabolites.
• Ketogenic diets (KD/VLCKD) led to weight loss and glycemic improvements but reduced SCFA producers and *Bifidobacterium*, potentially impairing gut barrier function.

Conclusions:

• Diet and exercise exert specific effects on the gut microbiota-metabolism axis in MetS.
• MedDiet, DASH, and moderate exercise offer sustainable cardiometabolic benefits via the microbiota.
• Ketogenic diets require careful application, limited duration, and supervision due to potential negative impacts on gut microbiota resilience.