This review systematically evaluates the effects of various dietary components on the intestinal microbiome and their implications for human health. The gut microbiome, comprising 10^14 microorganisms, plays a crucial role in modulating the risk of several chronic diseases, including inflammatory bowel disease, obesity, type 2 diabetes, cardiovascular disease, and cancer. Diet has been shown to significantly shape the microbiome, with dietary alterations inducing large, temporary microbial shifts within 24 hours. The review highlights that specific types of food consumption produce predictable shifts in existing host bacterial genera, which affect host immune and metabolic parameters. Key findings include: 1. **Protein**: High animal-based protein diets increase counts of *Bacteroides* and *Clostridia*, while plant-based proteins enhance *Bifidobacterium* and *Lactobacillus*. Animal protein is associated with reduced *Roseburia* and *Eubacterium rectale*, which may contribute to the increased risk of inflammatory bowel disease. 2. **Fats**: High saturated and trans fats increase the risk of cardiovascular disease, while health-promoting fats like mono and polyunsaturated fats alleviate this risk. High-fat diets increase *Bacteroides* counts, while high monounsaturated fat diets reduce total bacterial load and plasma cholesterol. 3. **Carbohydrates**: Digestible carbohydrates (starch, sugars) and non-digestible carbohydrates (fiber) both influence the microbiome. Digestible carbohydrates enrich *Bifidobacterium* and *Lactobacillus*, while non-digestible carbohydrates also increase *Ruminococcus*, *E. rectale*, and *Roseburia*. Prebiotics, such as resistant starch and whole grains, enhance *Bifidobacterium* and *Lactobacillus*. 4. **Probiotics and Polyphenols**: Fermented foods containing lactic acid bacteria (probiotics) and dietary polyphenols (e.g., catechins, flavonols) positively impact the gut microbiome, enhancing *Bifidobacterium* and *Lactobacillus* while reducing *Clostridia*. 5. **Popular Diets**: The Western diet, high in animal protein and fat, low in fiber, decreases total bacteria and beneficial *Bifidobacterium* and *Eubacterium*. The Mediterranean diet, rich in monounsaturated and polyunsaturated fatty acids, polyphenols, fiber, and vegetables, is associated with increased fecal SCFAs and *Prevotella* bacteria. The review concludes that maintaining a healthy gut microbiome is critical for overall health, and dietary interventions can potentially manage complex diseases like obesity and diabetes. Advances in microbiome research offer new therapeutic possibilities, including fecal microbiota transplants and personalized nutrition. Further research is needed to evaluate the long-term effects of dietary interventions on the microbiome and human healthThis review systematically evaluates the effects of various dietary components on the intestinal microbiome and their implications for human health. The gut microbiome, comprising 10^14 microorganisms, plays a crucial role in modulating the risk of several chronic diseases, including inflammatory bowel disease, obesity, type 2 diabetes, cardiovascular disease, and cancer. Diet has been shown to significantly shape the microbiome, with dietary alterations inducing large, temporary microbial shifts within 24 hours. The review highlights that specific types of food consumption produce predictable shifts in existing host bacterial genera, which affect host immune and metabolic parameters. Key findings include: 1. **Protein**: High animal-based protein diets increase counts of *Bacteroides* and *Clostridia*, while plant-based proteins enhance *Bifidobacterium* and *Lactobacillus*. Animal protein is associated with reduced *Roseburia* and *Eubacterium rectale*, which may contribute to the increased risk of inflammatory bowel disease. 2. **Fats**: High saturated and trans fats increase the risk of cardiovascular disease, while health-promoting fats like mono and polyunsaturated fats alleviate this risk. High-fat diets increase *Bacteroides* counts, while high monounsaturated fat diets reduce total bacterial load and plasma cholesterol. 3. **Carbohydrates**: Digestible carbohydrates (starch, sugars) and non-digestible carbohydrates (fiber) both influence the microbiome. Digestible carbohydrates enrich *Bifidobacterium* and *Lactobacillus*, while non-digestible carbohydrates also increase *Ruminococcus*, *E. rectale*, and *Roseburia*. Prebiotics, such as resistant starch and whole grains, enhance *Bifidobacterium* and *Lactobacillus*. 4. **Probiotics and Polyphenols**: Fermented foods containing lactic acid bacteria (probiotics) and dietary polyphenols (e.g., catechins, flavonols) positively impact the gut microbiome, enhancing *Bifidobacterium* and *Lactobacillus* while reducing *Clostridia*. 5. **Popular Diets**: The Western diet, high in animal protein and fat, low in fiber, decreases total bacteria and beneficial *Bifidobacterium* and *Eubacterium*. The Mediterranean diet, rich in monounsaturated and polyunsaturated fatty acids, polyphenols, fiber, and vegetables, is associated with increased fecal SCFAs and *Prevotella* bacteria. The review concludes that maintaining a healthy gut microbiome is critical for overall health, and dietary interventions can potentially manage complex diseases like obesity and diabetes. Advances in microbiome research offer new therapeutic possibilities, including fecal microbiota transplants and personalized nutrition. Further research is needed to evaluate the long-term effects of dietary interventions on the microbiome and human health