TY  - JOUR
T1  - Moving from Microbiome Association to Biological Causation in Insects: Standards for Colonization, Function, Mediation, and Phenotypic Attribution
A1  - Mina Takeda
A1  - Haruto Suzuki
A1  - Santiago Morales
A1  - Laura Rojas
JF  - Entomology and Applied Science Letters
JO  - Entomol Appl Sci Lett
SN  - 2349-2864
Y1  - 2025
VL  - 12
IS  - 3
DO  - 10.51847/FwfGhXC4e1
SP  - 13
EP  - 23
N2  - Insect microbiome research increasingly links microbial composition to host development, nutrition, immunity, behaviour, pathogen susceptibility, and environmental adaptation. Yet an observed association between a microbial feature and a host phenotype does not by itself establish that the microorganism colonizes the relevant host compartment, remains present for a biologically meaningful period, performs the proposed function in situ, mediates the phenotype, or acts independently of environmental and host-derived confounders. This article develops an original, explicitly non-validated standards structure for moving from microbiome association to defensible biological causation in insects. The approach integrates evidence requirements across microbial detection, colonization, persistence, functional activity, mediation, mechanistic validation, phenotypic attribution, contextual control, and experimental reproducibility. The central synthesis is that causal confidence should increase only when successive evidence domains are connected: spatially and temporally resolved microbial presence; evidence of establishment rather than transient passage; demonstration of molecular or metabolic activity; perturbation and restoration of the proposed microbial function; identification of host or pathogen pathways linking that function to an outcome; and replication across relevant biological and environmental contexts. No individual experiment is treated as universally decisive. Axenic, gnotobiotic, reconstitution, genetic, metabolic, imaging, and community-manipulation approaches each resolve different causal questions while introducing distinct artefacts and boundary conditions. Phenotypic rescue strengthens attribution but does not necessarily identify a complete mechanism, and statistical mediation remains inferential until the proposed mediator is experimentally manipulated. The proposed standards therefore emphasize staged validation, explicit alternative explanations, ecological relevance, and transparent limits on generalization. Their primary implication is that insect microbiome experiments should be designed around predefined causal claims and discriminating tests rather than around taxonomic association alone.
UR  - https://easletters.com/article/moving-from-microbiome-association-to-biological-causation-in-insects-standards-for-colonization-f-n89xxpl32txjkvn
ER  -