A study published in Nature (DOI: 10.1038/s41591-023-02761-2) investigated the impact of vegan and ketogenic diets on human immunity and the microbiome. The research involved 20 participants who sequentially consumed either a vegan or ketogenic diet for two weeks. Using a multi-omics approach, including flow cytometry, transcriptomics, proteomics, metabolomics, and metagenomics, the study found that a ketogenic diet significantly upregulated pathways related to adaptive immunity, including T cell activation and B cell enrichment. In contrast, a vegan diet had a significant impact on the innate immune system, including pathways associated with antiviral immunity. Both diets significantly and differently affected the microbiome and host-associated amino acid metabolism, with a strong downregulation of microbial pathways following the ketogenic diet compared to baseline and vegan diet. The study revealed a tightly connected network between datasets driven by compounds associated with amino acids, lipids, and the immune system. The findings suggest that a two-week controlled dietary intervention can significantly and divergently impact host immunity, with implications for precision nutritional interventions. The study also showed that a ketogenic diet had a broader impact on the proteome, with significant downregulation of microbial amino acid metabolism. In contrast, a vegan diet was associated with upregulation of heme metabolism and erythrocyte differentiation. The study highlights the importance of diet in shaping the microbiome and host immunity, with implications for understanding the impact of different diets on health and disease. The results suggest that both diets have significant effects on host immunity, with the ketogenic diet showing a more pronounced impact on proteome, metabolome, and microbiome data. The study also found that a vegan diet was associated with upregulation of innate immunity and erythropoiesis. The findings indicate that diet can significantly influence host immunity and metabolism, with potential implications for the prevention and treatment of diseases such as cancer. The study underscores the need for further research to understand the mechanisms by which diet impacts immunity and metabolism, and to explore the potential of dietary interventions in improving human health.A study published in Nature (DOI: 10.1038/s41591-023-02761-2) investigated the impact of vegan and ketogenic diets on human immunity and the microbiome. The research involved 20 participants who sequentially consumed either a vegan or ketogenic diet for two weeks. Using a multi-omics approach, including flow cytometry, transcriptomics, proteomics, metabolomics, and metagenomics, the study found that a ketogenic diet significantly upregulated pathways related to adaptive immunity, including T cell activation and B cell enrichment. In contrast, a vegan diet had a significant impact on the innate immune system, including pathways associated with antiviral immunity. Both diets significantly and differently affected the microbiome and host-associated amino acid metabolism, with a strong downregulation of microbial pathways following the ketogenic diet compared to baseline and vegan diet. The study revealed a tightly connected network between datasets driven by compounds associated with amino acids, lipids, and the immune system. The findings suggest that a two-week controlled dietary intervention can significantly and divergently impact host immunity, with implications for precision nutritional interventions. The study also showed that a ketogenic diet had a broader impact on the proteome, with significant downregulation of microbial amino acid metabolism. In contrast, a vegan diet was associated with upregulation of heme metabolism and erythrocyte differentiation. The study highlights the importance of diet in shaping the microbiome and host immunity, with implications for understanding the impact of different diets on health and disease. The results suggest that both diets have significant effects on host immunity, with the ketogenic diet showing a more pronounced impact on proteome, metabolome, and microbiome data. The study also found that a vegan diet was associated with upregulation of innate immunity and erythropoiesis. The findings indicate that diet can significantly influence host immunity and metabolism, with potential implications for the prevention and treatment of diseases such as cancer. The study underscores the need for further research to understand the mechanisms by which diet impacts immunity and metabolism, and to explore the potential of dietary interventions in improving human health.