Anti-biofilm potential of Matricaria chamomilla against tetra species representative gut commensals.

In this study, we investigated the effects of supratherapeutic concentrations of M. chamomilla extract on a tetra-species biofilm model comprising Escherichia coli, Enterococcus faecalis, Lactobacillus plantarum, and Lactobacillus fermentum. Phytochemical screening and GC–MS analysis revealed multiple bioactive compounds, including alkaloids and flavonoids, with potential anti-biofilm activity. Dose-dependent exposure to the extract resulted in a marked reduction in biofilm biomass and cell viability. At 30 µg/mL, biofilm inhibition reached approximately 52–80%, while viable cell counts decreased by more than 55%. FE-SEM confirmed distinct disruption of biofilm structure, and 16S rRNA sequencing indicated a decline in microbial diversity, with the Shannon index falling from 1.1 to 0.9 and observed OTUs decreasing from ~ 200 to ~ 150. These findings suggest that M. chamomilla is generally regarded as beneficial, excessive supplementation may adversely affect gut microbial composition and biofilm stability, highlighting the need for careful use under appropriate guidance.