Belgian researchers have highlighted in a study the immunostimulant potential of sea spray aerosols.
- Sea spray aerosols activate immune defenses in human cells.
- The immune defenses in question are “those that respond in the event of an unknown attack, and those that memorize an enemy to eliminate it more quickly if it returns.”
- Immune responses demonstrated dose dependence of bacterial components.
“Frequent exposure to sea spray aerosols containing marine microorganisms and bioactive compounds may influence human health. However, little is known about the potential immunostimulation due to exposure to marine aerosols,” said scientists from the Flemish Marine Institute in Ostend, Belgium. They therefore decided to conduct a study that focuses on the effects of marine bacteria and endotoxins, i.e. complex molecules, components of the cell wall of certain bacteria, present in sea spray aerosols on several receptors and known to play a key role in the human innate immune system.
As part of their work, published in the journal Science of The Total Environmentt, they collected samples of sea spray aerosols a few meters from the waves on the Belgian coast or in the laboratory. The samples were characterized by their sodium content, total bacterial counts and endotoxin concentrations. Then, the collected microdroplets were placed in contact with human cells for 24 hours to examine the effects on the immune system.
Exposure to sea spray aerosols stimulates immune defenses
Sea spray aerosol samples “differentially activated toll-like receptor 4 (TLR4) in HEK-Blue hTLR4 cells and TLR2/6 in HEK-Blue hTLR2/6 cells, as well as nuclear factor kappa B (NF-κB) and interferon regulatory factors (IRFs) in THP1-Dual monocytes. These immune responses correlated in a dose-dependent manner with total bacterial counts, endotoxin levels, or both,” can be read in the results.
In short, marine bacteria present in water droplets blown by the wind stimulate two key families in our immune defenses. “Those that respond in the event of an unknown attack, and those that memorize an enemy to eliminate it more quickly if it returns. For Professor Jana Asselman (co-author of the work), this creates a better reactivity in the event of infection.”explained journalist Géraldine Zamansky on FranceInfo.
Examining the bacterial flora in the noses of locals, seaside holidaymakers and city dwellers
In the research conclusions, the authors state that further research is needed to further understand the health implications of exposure to sea spray aerosols. In their next study, they will attempt to identify which bacteria are beneficial and how they work by using Covid test swabs to analyze the bacterial flora in the noses of locals and seaside vacationers, and then compare it with that of city dwellers.