It is an object of the present invention to provide a biological information measurement system capable of notifying poor physical condition. The present invention is a system (1) that measures physical condition on the basis of defecation gas, and that includes: a test subject identification device; a suction device (18) that sucks gas in a bowl; a gas detector (20) that reacts to methyl mercaptan gas contained in the sucked gas; a control device (22) that controls the suction device and the gas detector; a storage device that stores first detection data; a data analyzer that analyzes physical condition of a test subject on the basis of time-dependent change in a plurality of first detection data items that is acquired in a defecation act performed multiple times in a predetermined period; and an output device that outputs an analysis result.