7. Conclusion and future perspective
In this review article, we summarized the characteristics of gut microbiota in specific age groups. An essential step for the health improvement throughout life is by establishing a “healthy gut microbiota” at an early age. Targeting the gut microbiota by dietary fibers may help resist the diseases and extend the life span. Diet and lifestyle are crucial environmental factors that result in different gut microbiome between rural and urban communities. We systematically described the associations between the gut microbiota and three clustered diseases including metabolic, immunological and neurological diseases, respectively. Numerous diseases are associated with the dysbiosis of gut microbiota, indicating the key role of gut microbiota in human health is connecting all parts of the body into a whole organized system. More importantly, it appears that the relationship between the gut microbiota dysbiosis and the occurrence of some diseases is neither causal nor consequential, but bidirectional. Thus, the gut microbiota may directly or indirectly participate in the initiation of diverse diseases. Finally, potential nutritional and therapeutic strategies modifying the gut microbiota (prebiotics, probiotics, drugs and FMT) are introduced for treating or preventing diseases. Further researches focusing on elucidating the underlying mechanisms are warranted. Nevertheless, there is no doubt that the development and application of these approaches will bring great opportunities for the improvement of human health.