Role of gut microbiome and their mode of action against various metabolic syndromes
| Aspect of metabolic syndrome | Role of the gut microbiota (GM) | Mechanisms of action | References |
|---|---|---|---|
| Obesity | GM composition is linked to obesity risk | Dysbiosis (imbalance of GM) may lead to increased energy extraction from food and altered fat storage. Certain bacteria, such as those belonging to the Firmicutes group, are associated with a higher energy harvest from food, which contributes to weight gain. | Alou et al. [17], 2016; Amabebe et al. [18], 2020 |
| Insulin resistance | GM affects insulin sensitivity | The altered gut microbiome can influence insulin resistance by increasing inflammation, producing metabolites such as short-chain fatty acids (SCFAs) that improve insulin function, or modifying bile acid metabolism. | Saad et al. [19], 2016; Visekruna and Luu [20], 2021 |
| High blood pressure | GM may influence blood pressure regulation | An imbalance in GM can lead to an increased production of endotoxins, which promote inflammation and hypertension. Gut-produced SCFAs can help regulate blood pressure by affecting vascular tone and sodium balance. | Mozaffarian and Wu [21], 2018 |
| Dyslipidemia | Microbiota affects lipid metabolism | Gut bacteria can influence lipid metabolism, bile acid synthesis, and the absorption of fat. Dysbiosis can lead to elevated levels of LDL cholesterol, triglycerides, and reduced HDL cholesterol. Beneficial bacteria, such as Lactobacillus and Bifidobacterium, may help improve lipid profiles. | Schoeler and Caesar [22], 2019; Wang et al. [23], 2019; Zarezadeh et al. [24], 2023 |
| Inflammation | Dysbiosis promotes chronic low-grade inflammation | An imbalance in GM increases gut permeability (“leaky gut”), allowing endotoxins to enter the bloodstream and trigger systemic inflammation. This inflammation contributes to metabolic dysfunction and the development of metabolic syndrome. | Candelli et al. [25], 2021 |
| NAFLD | GM plays a role in liver health | The gut microbiome can influence liver fat accumulation and inflammation. Dysbiosis may contribute to the development of fatty liver disease by increasing intestinal permeability and triggering an inflammatory response in the liver. | Saltzman et al. [26], 2018; Yaghmaei et al. [14], 2024 |
| Endotoxemia | GM contributes to endotoxin production | An imbalanced gut microbiome, especially with an overgrowth of gram-negative bacteria, can lead to the production of lipopolysaccharides (LPS), which are pro-inflammatory and contribute to the development of metabolic syndrome. | Çakirlar [27], 2025 |
| Gut-brain axis | The gut microbiome influences appetite and metabolism through the gut-brain axis | GM affects the release of appetite-regulating hormones such as ghrelin and leptin, influencing hunger and satiety signals. Altered microbiota can disrupt these signals, contributing to overeating and obesity. | Han et al. [28], 2021; Smitka et al. [29], 2021 |
| SCFAs | SCFAs produced by GM are beneficial for metabolic health | SCFAs (e.g., acetate, propionate, butyrate) help regulate glucose metabolism, reduce inflammation, and improve insulin sensitivity. SCFAs are produced by the fermentation of dietary fibers by beneficial gut bacteria. | Koh et al. [30], 2016; Portincasa et al. [31], 2022 |
| Bile acid metabolism | The gut microbiome plays a crucial role in regulating bile acid metabolism | Gut bacteria modify bile acids, which in turn influence fat digestion and absorption. Altered bile acid metabolism can affect lipid metabolism, insulin sensitivity, and the development of metabolic diseases. | Chávez-Talavera et al. [32], 2017; Ramirez-Pérez et al. [33], 2017 |
| Microbial diversity | Greater microbial diversity is associated with better metabolic health | Higher microbial diversity is associated with a healthier metabolic profile, improved immune function, and reduced inflammation. Low diversity is often associated with obesity, insulin resistance, and dyslipidemia. | Aron-Wisnewsky et al. [34], 2021; Vallianou et al. [35], 2019 |
NAFLD: non-alcoholic fatty liver disease
