A low dose of an organophosphate insecticide causes dysbiosis and sex-dependent responses in the intestinal microbiota of the Japanese quail (Coturnix japonica)Original paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
The study examined how a single, low-concentration dose of the organophosphate insecticide trichlorfon affects the gastrointestinal microbiome of the Japanese quail. Researchers used next-generation sequencing of 16S rRNA gene amplicons to characterize bacterial communities in three sample origins: caecum, large intestine, and faeces. The design captured short-term microbial community responses following oral insecticide exposure, mimicking how birds encounter organophosphates in agricultural settings through ingestion of treated invertebrates.
Who was studied?
The subjects were Japanese quail (Coturnix japonica), used as an avian model rather than wild birds directly. The abstract indicates both treated and untreated (control) quail of both sexes were compared, since sex-dependent differences are reported, but it does not give an exact number of birds. Sampling was drawn from three gastrointestinal compartments (caecum, large intestine, faeces) within this quail cohort.
What were the most important findings?
Ingestion of the insecticide caused significant changes in gut microbiome composition and diversity between treated and untreated quail. The caecal microbiota showed sex-dependent responses that were not seen in the large intestine or faecal samples. Specifically, only treated females exhibited significant shifts in several genera within the Lachnospiraceae and Enterobacteriaceae families in the caecum.
What are the greatest implications of this study?
The findings show that even a low, sublethal dose of an organophosphate insecticide can disrupt the avian gut microbiome, with effects that depend on both sex and gut region sampled. Because shifts occurred within the Enterobacteriaceae family, a group that includes Salmonella enterica and other enteric pathogens, insecticide-driven dysbiosis could plausibly alter colonization resistance against such organisms in exposed birds. This suggests pesticide exposure may have previously underappreciated indirect effects on avian gut health and disease susceptibility, warranting further study of GIT microbiota as a pathway linking agricultural chemical exposure to bird population declines.