To provide a mixture, a dissolving solution and a pharmaceutical agent, which contain a thermophilic microorganism to make it possible to regulate a mucous membrane immune system gene cluster and metabolism-related gene clusters of the intestines and the liver. Each of them is prepared by fermentation of an organic material containing a thermophilic microorganism at a temperature of 50° C. or more and 90° C. or less. By being administered to the animal, it regulates at least one of a mucous membrane immune system gene cluster, a metabolism-related gene cluster in the intestines, and a metabolism-related gene cluster in the liver of the animal. The microorganism includes at least one species of the genus Bacillus, Oceanobacillus, Paenibacillus, Anoxybacillus, Lysinibacillus, Methanopyrus, Geogemma, Pyrolobus, Pyrodictium, Hyperthermus, Pyrococcus, Pyrobaculum, Thermococcus, Aeropyrum, Aquifex, Thermotoga, Thermodesulfobacterium, Thermus, Geobacillus, and Thermomyces.