[Intestinal microbiota biodiversity and the modern diet: consequences for human health]

The advent of the modern diet - characterized by increased consumption of ultra-processed foods rich in saturated fats and simple sugars, but deficient in fiber and micronutrients - has profoundly altered the biodiversity of the intestinal microbiota. This dysbiosis disrupts the intricate metabolic, immune, and nutritional interactions between the host and its microbiota, leading to significant downstream impacts on human health. Dietary imbalances result in reduced production of beneficial microbial metabolites, increased intestinal permeability, chronic inflammation, and heightened risks of obesity, diabetes, and inflammatory diseases. Conversely, diversified diets rich in fiber, unsaturated fatty acids, and plant-based proteins support a resilient and diverse microbial ecosystem that enhances gut barrier function, immunity, and the synthesis of protective compounds. A deeper understanding of these complex host-microbiota-nutrition interactions can pave the way for preventive and therapeutic strategies targeting the microbiome to promote human health.