Mapping the regulatory effects of herbal organic compounds on gut bacteria

Herbal organic compounds (HOCs) are bioactive natural products from medicinal plants and some traditional Chinese medicines (TCMs). Recently, ingestion of a few HOCs with low bioavailability has been associated with alterations in gut microbiota, but the extent of this phenomenon remains unclear. Here, we systematically screened 481 HOCs against 47 representative gut bacterial strains in vitro and found that almost one-third of the HOCs exhibited unique anticommensal activity. Quinones showed a potent anticommensal activity, while saturated fatty acids exhibited stronger inhibition of the Lactobacillus genus. Flavonoids, phenylpropanoids, terpenoids, triterpenoids, alkaloids and phenols displayed weaker anticommensal activity, but steroids, saccharides and glycosides had hardly any effect on strain growth. Notably, S-configuration HOCs demonstrated stronger anticommensal activity than R-configuration HOCs. The strict screening conditions ensured high accuracy (95%) through benchmarking validation. Additionally, the effects of HOCs on human fecal microbiota profiling were positively correlated with their anticommensal activity against bacterial strains. Molecular and chemical features such as AATS3i and XLogP3 were correlated with the anticommensal activity of the HOCs in the random forest classifier. Finally, we validated that curcumin, a polyhydric phenol with anticommensal activity, improved insulin resistance in HFD mice by modulating the composition and metabolic function of gut microbiota. Our results systematically mapped the profile of HOCs directly affecting human gut bacterial strains, offering a resource for future research on HOC-microbiota interaction, and broadening our understanding of natural product utilization through gut microbiota modulation.