Abstract:The gut is a complex ecosystem of host cells, available nutrients and microbiota. The microbiota have close relationship to the host nutrition, metabolism, physiology and immunity, and their disorder will lead to various diseases. Clinical tests indicate that lactic acid bacteria (LAB) with probiotic function can cure or relieve many diseases. This review described three methods for quantifying homeostasis of gut microbiota and their application and elaborated the effect of LAB with probiotic function on the gut microbiota homeostasis of obese and healthy hosts. This literature also pointed out the possible beneficial mechanisms: 1) competing with the pathogenic bacteria in the intestinal tract to bind the site or secreting substance to inhibit the growth of pathogenic bacteria; 2) secreting metabolites to provide livable environment for growth and reproduction of beneficial symbiotic bacteria in the intestinal tract; 3) creating imaginary enemies to stimulate the host immune response. The significance of balancing the host gut microbiota homeostasis was also discussed. Finally, perspectives for probiotic LAB were summarized, and in the future research of probiotic LAB should be personalized, considering not only the individual difference of test population but also the difference among the strains.
