The study found that the natural antimicrobial peptide LL‑37 can kill tough, drug‑resistant E. coli bacteria and works even better when paired with the antibiotic colistin. Together they stopped bacterial growth faster and also lowered the bacteria's ability to form protective biofilms. However, colistin is a powerful drug with serious side effects, and LL‑37 isn’t available as a safe supplement, so the findings are more about future medical treatments than something you can try at home now.

<b>Overview:</b> The global spread of antibiotic resistance represents a serious threat for public health. <b>Aim:</b> We evaluated the efficacy of the antimicrobial peptide LL-37 as antimicrobial agent against multidrug-resistant <i>Escherichia coli</i>. <b>Results:</b> LL-37 showed good activity against <i>mcr</i>-1 carrying, extended spectrum &#x3b2;-lactamase- and carbapenemase-producing <i>E. coli</i> (minimum inhibitory concentration, MIC, from 16 to 64&#xa0;mg/l). Checkerboard assays demonstrated synergistic effect of LL-37/colistin combination against all tested strains, further confirmed by time-kill and post antibiotic effect assays. MIC and sub-MIC concentrations of LL-37 were able to reduce biofilm formation. <b>Conclusion:</b> Our preliminary data indicated that LL-37/colistin combination was effective against multidrug-resistant <i>E. coli</i> strains and suggested a new possible clinical application.