Embodiments of this invention include systems and methods for developing individualized dietary and health improvement plans based on an individual's intestinal microbiome and digestive activity. More particularly, the invention is related to a system providing a hydrogen and/or methane sensor device and a wireless platform in communication with the sensor device to periodically analyze the individual's metabolic activity in correlation with their gut microbiome and a personal database to provide personalized feedback to the individual of treatment plans and general techniques that can be used to improve the individual's general health and well being. The systems and methods further include a system for analyzing the hydrogen and/or methane levels in the individual's exhalations or flatulence in light of the individual's intestinal microbiome. This analysis uses bioinformatics to relate alterations in hydrogen and/or methane levels to the individual's intestinal microbiome and personal diet and tolerances/intolerances to identify and communicate real time dietary suggestions and general dietary and health treatment plans. The relationship of the bioinformatics and alterations in hydrogen and/or methane levels is also used to infer drug effectiveness. Such general dietary guidance, health treatment plans, and drug effectiveness contribute to an overall improvement in a person's general health and well being.