Influence of different dietary patterns on insulin sensitivity and gut microbiome.
| Dietary pattern | Features | Influence on insulin sensitivity and gut microbiome | References |
|---|---|---|---|
| Vegetarian | Emphasizes plant-based foods rich in fiber, vitamins, minerals, and polyphenols | Increases beneficial taxa such as Lactobacillus, Bifidobacterium, and butyrate-producing bacteria while reducing pro-inflammatory or pathogenic species associated with metabolic dysfunction. Higher fiber intake enhances fermentation and short-chain fatty acid (SCFA) production, particularly butyrate, which lowers systemic inflammation, improves insulin signaling, and strengthens gut barrier integrity. It also reduces trimethylamine-N-oxide (TMAO) synthesis. | [111, 112] |
| Mediterranean | Rich in fruits, legumes, nuts, olive oil, and wine, but low in red meat, refined sugars, and processed foods | Promotes SCFA production that enhances gut barrier integrity, reduces inflammation, and supports metabolic homeostasis. Increases beneficial bacteria such as Bifidobacterium, Faecalibacterium prausnitzii, and Roseburia. Also elevates neuroprotective metabolites like indole-3-propionic acid, demonstrating rapid dietary modulation of microbiota and associated metabolites. | [113–115] |
| Dietary approaches to stop hypertension (DASH) | Limits sodium (1,500–2,300 mg/day) and promotes whole grains, low-fat dairy, nuts, fish, poultry, fruits, and vegetables | Improves the Firmicutes/Bacteroidetes ratio and significantly reduces TMAO and LPS, both markers of microbial dysbiosis. Its high flavonoid and plant-fiber content support gut barrier integrity and reduces inflammation. Long-term adherence independently lowers fasting insulin, while combined interventions (e.g., exercise, caloric restriction) further enhance insulin sensitivity, as shown in ENCORE and PREMIER trials. | [116–118] |
| Ketogenic | Low-carbohydrate, high-fat diet designed to induce ketosis | Improves HDL and reduces LDL, triglycerides, HbA1c, and fasting glucose in individuals with T2DM. However, it decreases fecal SCFAs, Bifidobacterium, and butyrate-producing Firmicutes. Prolonged reductions in Bifidobacterium may carry risks, including susceptibility to obesity, T2DM, and mood disturbances. | [112, 119, 120] |
| Western | Characterized by high-fat, high-sugar, heavily processed foods | Reduces SCFA production, increases TMAO levels, and promotes pro-inflammatory microbial groups including LPS-producing bacteria. Leads to dysbiosis, systemic inflammation, and elevated T2DM risk. | [121, 122] |
| Animal-based | High intake of animal fats, dairy, eggs, and meat (while low in fruits, vegetables, legumes, and whole grains) | Increases Bacteroides, Alistipes, and Bilophila, while reducing beneficial taxa such as Lactobacillus, Roseburia, and Eubacterium rectale. Reduced SCFA production and increased LPS and inflammatory cytokines contribute to impaired metabolic function. | [123, 124] |
The authors extend their sincere gratitude to the Department of Food Science & Technology at Graphic Era (Deemed to be University), Dehradun, Uttarakhand, India, for offering the essential facilities required for the preparation of this review paper.
SJ: Conceptualization, Investigation, Data curation, Writing—original draft. DB: Conceptualization, Writing—review & editing. AD: Conceptualization, Writing—review & editing. RK: Conceptualization, Writing—review & editing. RM: Conceptualization, Writing—review & editing. SK: Writing—review & editing. All authors read and approved the submitted version.
The authors declare that they have no conflicts of interest.
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