Antibiofilm activity of Human Milk Oligosaccharides against pathogens isolated from cystic fibrosis patients

Background: Human milk oligosaccharides (HMOs) are the third most abundant component of breast milk, after fat and lactose, that promote infant health. Recent studies have shown that HMOs demonstrated antimicrobial and antibiofilm activity against different strains. Cystic fibrosis (CF), it is one of the major respiratory diseases, the clinical management and definitive treatment of CF biofilm-mediated chronic bacterial lung infection remains a challenge.

Objective: In this study, we examine HMOs antibiofilm activity against pathogens isolated from CF patients.

Methods and results: In current work, we investigated the antibiofilm activity of the saccharide fraction obtained from pooled human milk of 9 donors against strains of: Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacteriaceae, Staphylococcus aureus and Burkholderia cenocepacia, an intrinsically multi-resistant pathogen associated with high mortality in CF patients. We tested the ability of HMOs to inhibit biofilm formation and to eradicate matured biofilms. Live/dead staining of the biofilms and CLSM image acquisition were used.

The pooled HMOs showed a biofilm eradicating effect on most tested pathogens. The HMOs effectively killed the bacteria at high concentration (20 mg/ml, corresponds to the concentration in human milk), but visible reduction of viable bacteria and biofilm mass was observed already at lower concentrations that varied between the species. The biofilm mass was also reduced in almost all pathogenic biofilms.

The data presented in this paper supporting the importance and potential inhibitory effect of HMOs in biofilm formation. HMOs could potentially be used as novel therapeutics to treat or prevent infectious disease in patient with CF.