Abstract: A bacteriophage which consists of the nucleotide sequence represented by SEQ ID NO: 1 or a nucleotide sequence having 90% or more identity thereto, as its genome, is capable of infecting and lysing a diabetes-inducible bacterium belonging to Fusimonas intestini,containing a cyclic single-stranded DNA.

Abstract: A method for analyzing a microbiota, comprising (1) dissolving a probe capable of non-specifically interacting with a plurality of microorganisms in a plurality of solvents having different ionic strengths and pH levels, wherein the probe comprises: (a) a cationic polymer and (b) an environment-sensitive fluorophore; (2) adding a test sample containing the microbiota to a plurality of probe solutions prepared in the step (1), thereby microorganisms in the test sample and the probe are interacted non-specifically; (3) measuring fluorescence intensities of the plurality of probe solutions to which the test sample has been added in the step (2); and (4) comparing the pattern of fluorescence intensities obtained in the step (3) with the pattern of fluorescence intensities obtained from a reference sample.