Diet affects metabolism and gut microbiome significantly: Study

In a recent study published in the journal CELL, researchers discussed recent advances in molecular nutrition. They focused on pharmaceutical and dietary interventions to manage energy balance and their interactions with the gut microbiome in humans. Further, they explored emerging dietary patterns and the implications of microbiome research on nutrition.

Over the past five decades, molecular nutrition has evolved significantly. Initially centered on micronutrients, the field has shifted towards studying macronutrients and dietary patterns, driven in part by the rising prevalence of obesity. A growing body of evidence highlights the crucial role of the gut microbiome in regulating energy metabolism and dietary responses. This has led to the emergence of precision nutrition, which tailors dietary recommendations based on an individual's genetic and microbiome profiles. Large-scale studies, such as the Personalised Responses to Dietary Composition Trial (PREDICT), have demonstrated the potential of incorporating microbiome data to improve metabolic health outcomes. Nevertheless, further research is needed to validate precision nutrition and integrate it into clinical practice.

This study focuses on recent advancements in diets, energy balance, and the gut microbiome. It intentionally excludes discussions on dietary sugars, plant-based diets, genetically modified organisms (GMOs), and undernutrition. The goal is to highlight the rapid progress and general concepts that can be applied to other areas of nutrition research.

Recent developments in human nutrition are challenging traditional guidelines that emphasize fat restriction, instead embracing diets with moderate to high fat intake. One prominent example is the Mediterranean diet (MD), which is rich in whole grains, legumes, fruits, vegetables, nuts, seeds, and olive oil. This diet has been shown to reduce body weight, body mass index, blood pressure, low-density lipoprotein (LDL) cholesterol, triglycerides, insulin resistance, and inflammation. It also lowers mortality and reduces the risks of type 2 diabetes (T2D) and certain cancers. The beneficial mechanisms of the MD include lipid-lowering effects, protection against oxidative stress, and inhibition of nutrient-sensing pathways. Additionally, the MD positively impacts the gut microbiome by increasing fibre-degrading taxa and promoting beneficial metabolic phenotypes.

It is concluded that diet significantly impacts metabolism and the gut microbiome. Balanced diets like the Mediterranean diet enhance metabolic health and beneficial gut bacteria, while restrictive diets like the ketogenic diet may offer short-term benefits but pose risks of nutrient deficiencies and negative changes in gut microbiome composition.

References: Digesting the complex metabolic effects of diet on the host and microbiome. Carmody, Rachel N. et al., Cell, Volume 187, Issue 15, 3857 – 3876 (2024), DOI: 10.1016/j.cell.2024.06.032, https://www.cell.com/cell/fulltext/S0092-8674(24)00706-2