Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection. According to the Global Burden of Disease Study, it affects more than 50 million people annually and causes about 5.3 million deaths, with a case fatality rate of 20% to 50% depending on the population and health care setting. Intestinal microflora is the largest microbial ecosystem in the body, maintaining the integrity of the intestinal barrier, immune homeostasis and metabolic balance. It is involved in the pathogenesis, progression and outcome of sepsis by modulating immune responses, production of key metabolites and gut organ axis. The article examines sepsis-induced gut microflora dysbiosis, molecular mechanisms affecting immune and metabolic disorders and organ damage. It evaluates the clinical potential of microbiome biomarkers, advances in therapies such as microbiotic/prebiotic nutrition, antibiotics and fecal transplantation. The goal is to analyze research gaps and provide a basis for individualized microbiome-based management of sepsis.