Sub-health is an intermediate between health and disease， which is manifested by physical fatigue， sleep disorders， emotional depression， inability to adapt to the social environment， etc. It can directly or indirectly affect the physiology， psychology， social interaction， and other aspects of human being. Long-term sub-health state can even result in chronic diseases. In recent years， the state of sub-health has gradually attracted the attention of society， and how to prevent or alleviate sub-health has become a hotspot in related fields. Many basic and clinical studies showed that dysbiosis of gut microbiota was closely associated with the sub-health status of host， and targeted regulation of gut microbiota could improve the related symptoms. In this review， the gut microbiota from the sub-health population and the effect of probiotics on improving their harms were summarized. This article also proposes the possible mechanisms that probiotics could affect the production of short-chain fatty acids， neurotransmitters， hormones and other microbial metabolites to alleviate sub-health by regulating the composition and structure of gut microbiota， which provides new directions and strategies for the prevention and improvement of sub-health.