The gut microbiome is defined as the collective assembly of microbial communities inhabiting the gut, along with their genes and metabolic products. The gut microbiome systematically regulates host metabolism, immunity, and neuroendocrine homeostasis via interspecies interaction networks and inter-organ axes. Given the importance of the gut microbiome to the host, this review integrates the composition, function, and genetic basis of the gut microbiome with host genomics to provide a systematic overview of recent advances in microbiome–host interactions. This encompasses a complete technological pipeline spanning from in vitro to in vivo models to translational medicine. This technological pipeline spans from single-bacterium CRISPR editing, organoid–microbiome co-culture, and sterile/humanized animal models to multi-omics integrated algorithms, machine learning causal inference, and individualized probiotic design. It aims to transform microbiome associations into precision intervention strategies that can be targeted and predicted for clinical application through interdisciplinary research, thereby providing the cornerstone of a new generation of precision treatment strategies for cancer, metabolic, and neurodegenerative diseases.

(1) Background: Hydroponic forage plays an increasingly important role in animal breeding during winter and spring in arid and cold regions due to its rich nutrient and good palatability. In the present study, the profiles of growth, physiological indexes, nutritional value and in vitro degradation of hydroponic forage cultivated with different salt concentration were evaluated. (2) Methods: The compound salt was extracted from soil surrounding the Tarim River Basin, and five compound salt solution treatment groups (three replicates each) with concentrations of 0%, 0.4%, 0.8%, 1.2% and 1.6% were prepared. Winter wheat seeds were selected as hydroponic forage for germination experiments, and the germination, physiological indicators, nutritional value and in vitro fermentation degradation rate were analyzed. (3) Results: The results showed that the germination and growth of hydroponic herbage were significantly (p < 0.05) inhibited by compound salt concentration higher than 0.8% from the third day. Compared with the 0% concentration group, the chlorophyll content in the 0.4% concentration group was significantly increased (p < 0.05), and contents of chlorophyll a, chlorophyll b and total chlorophyll were 729.71 mg·g⁻¹, 223.19 mg·g⁻¹ and 952.9 mg·g⁻¹, respectively. The total chlorophyll content in the 0.8% and 1.2% concentration groups were significantly lower than those in the 0% and 0.4% concentration groups (p < 0.05), and in the 1.6% concentration group, the content undetected. With the increase in compound salt concentration, the contents of soluble sugar and proline were significantly increased (p < 0.05). The nutrient compositions were significantly increased (p < 0.05) under the 0.4% and 0.8% concentration groups, in which the content of crude protein in 0.4% concentration group was 15.23%. The results of gas production and fermentation parameters suggested that the 0.8% concentration group could enhance rumen fermentation characteristics. (4) Conclusions: In summary, 0.8% as the upper limit concentration and 0% to 0.4% as the optimal concentration range of compound salt can be considered for cultivating hydroponic forage wheat.