Embodiments of a method and/or system, such as for characterizing at least one microorganism-related condition, can include: determining a set of associations (e.g., positive associations such as positive correlations, negative associations such as negative correlations, non-associations such as no correlation or minimal correlation, etc.) between a set of microorganism taxa and at least one microorganism-related condition; determining a set of reference features (e.g., reference abundance ranges, etc.) for the set of microorganism taxa; and determining one or more significance index metrics based on the set of associations and the set of reference features.