What is the purpose of saline

7% saline helps by hydrating and loosening thick mucus in airways, making it easier to cough up and clear. Its use can help lung function and restore moisture to the airways. It's helpful to take a bronchodilator prior. Also, MAC/NTM, pseudomonas etc do not like a salinity environment.

@lorrainewenn - @scoop is right. There have been a number of studies showing that most strains of Mycobacteria cannot survive in a saline environment above 5%. For many of, that has meant being able to stay off antibiotics indefinitely.
Sue

From the research I have read, saline provides an inhospitable environment for MAC bacteria which helps slow down its growth. It has additional benefits but, for me, that is the most important attribute since I am not choosing to take the Big 3 antibiotics.

Can you provide those studies?

Does this mean that using the 3% Hyper-Sal is not sufficient to ward off MAC? I don't have any mucus and don't cough and am not on antibiotics but apparently I have tested positive for MAC in a sample. My doctor has me nebulizing only once a day with 3% and doing ACTs. He doesn't think I need 7%.

@sadair20 & @lorrainewenn - Here is the link to the most used study of hypertonic saline and Mycobacteria.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4850692/pdf/13104_2016_Article_2054.pdf

Feel free to read the entire discussion, but pay special attention to Table 2 on page 4. They grew various strains on plates in the lab, with varying concentrations of saline on the medium. By the time they reached 7% almost none of the strains was able to reproduce. Table 3 on page 5 also shows the sizes of the colonies that were able to grow at various concentrations - they decreased significantly at 5% saline and above.

Sue

@sueinmn Thank you so much! This is amazing.

For general pulmonologists who do not specialize in bronchiectasis with or without MAC, this seems a typical response that you "don't need 7%". Same happened with me. Finally, I convinced them to let me give 7% a trial. It made a big difference in clearance for me.

This is exactly what I was looking for! I’m a science nerd so I will study this and see if this article provides guidance on how long it might take for 7% saline, twice per day, to reduce MAC avium concentration in the lungs.

Absolutely!! I was originally placed on 3.5% and requested 7% based on the information provided in this chat group. I am now taking 4 weeks to test positive for MAC avium . Previously, I would test positive immediately on the smear test. I wonder if I increased frequency to three times per day, would be better.