A method to stimulate the biogenic production of a metabolite with enhanced hydrogen content that includes forming an opening in a geologic formation to provide access to a consortium of microorganisms, and injecting water into the opening to disperse at least a portion of the consortium over a larger region of a hydrocarbon deposit. The method may also include measuring a change in the rate of production of the metabolite in the formation. Also, an method to stimulate biogenic production of a metabolite that includes measuring a salinity level of formation water in a geologic formation, and injecting water into the opening to reduce the salinity level of the formation water in the formation. The method may also include measuring a change in the rate of production of the metabolite in the formation.