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Bisanz, J.

Publications and source records attributed to Bisanz, J..

2 recordsLinked to original sources

Interkingdom glycine conjugates of indole-3-carboxylates are Ah receptor ligands

Substituted indoles are conserved metabolites across all kingdoms of life and may function as a mediators of inter- and intra-species communication. Indole-3-carboxylates (indole-3-acetic acid (IAA) and indole-3-propionic acid (IPA)) represent abundant tryptophan-derived AHR agonists in human serum, potentially influencing AHR-dependent physiology. LC-MS analysis of mouse serum, urine and cecal/fecal contents reveals that both IAA and IPA undergo host and microbial mediated glycine conjugation to facilitate urinary elimination. Notably, at physiologically detectable human serum concentrations (M), IAA-Glycine retains human AHR activation potential. Comparative in silico docking simulations corroborate IAA-Glycine as a direct ligand for the human AHR. Data suggest, in contrast to xenobiotic ligands, AHR activation by endogenous tryptophan metabolites is greater in humans than in mice. These results underscore the role of microbial and host-derived amino acid conjugation in generating bioactive metabolites. Thus, positioning interkingdom auxin chemistry within human physiology and revealing an unexpected link between plants, microbes, and humans.

biochemistry↗

Human gut Actinobacteria boost drug absorption by secreting P-glycoprotein ATPase inhibitors

Drug efflux transporters are a major determinant of drug efficacy and toxicity. A canonical example is P-glycoprotein (P-gp), an efflux transporter that controls the intestinal absorption of diverse compounds. Despite reports that P-gp expression depends on the microbiome, the mechanisms responsible and their physiological relevance remain unclear. Surprisingly, we found that the cardiac drug-metabolizing gut Actinobacterium Eggerthella lenta increases drug absorption in mice through post-translational inhibition of P-gp ATPase efflux activity. P-gp inhibition is conserved in the Eggerthellaceae family but absent in other Actinobacteria. Comparative genomics identified genes associated with P-gp inhibition. Finally, activity-guided biochemical fractionation coupled to metabolomics identified a cluster of isoflavonoids produced by E. lenta related to plant-derived P-gp inhibitors. These results highlight the unexpected overlap between diet- and microbiome-derived compounds, and the importance of considering the broader relevance of the gut microbiome for drug disposition beyond first-pass metabolism. One Sentence SummaryThe gut bacterium Eggerthella lenta secretes inhibitors of P-glycoprotein ATPase activity, accelerating drug absorption.

microbiology↗