Abstract: The present invention relates to kits suitable for determining the ratio of succinate-producing bacteria to succinate-consuming bacteria in a stool sample from a subject, in particular the (Prevotellaceae+Veillonellaceae)/(Odoribacteriaceae+Clostridiaceae) ratio, or for determining the succinate level in a biofluid sample from a subject. The invention also relates to a method for determining whether a targeted intervention directed at reducing the levels of circulating succinate in a subject has been effective. Finally, the invention relates to targeted interventions for use in the prevention and/or treatment of a disease associated with increased levels of circulating succinate in a patient.