Probiotics are often associated with the treatment of intestinal problems. But times are changing and research is developing. Studies now suggest that probiotics can also give the battered immune system of smokers a boost!
Smokers generally have a significantly increased risk of respiratory diseases. Chronic bronchitis and chronic obstructive pulmonary disease (COPD) are the most common consequences of smoking.
The substances in tobacco smoke cause inflammatory reactions in the respiratory tract, irritate the bronchi, and increase the tendency to infection. In addition, smoking in adolescence reduces normal lung growth. Smoking is also the most common cause of COPD (chronic obstructive pulmonary disease).
90 percent of people suffering from COPD in Austria, for example, are current or former smokers.
Around two thirds (64%) of all COPD deaths are due to smoking. The number of cigarettes is also important: COPD mortality is up to 24 times higher in heavy smokers than in light smokers. Smokers die three times as often as non-smokers from respiratory diseases of all kinds, heavy smokers even five times as often.
What’s behind all this?
Firstly, smoking blocks the self-cleaning mechanism of the respiratory tract – paralysis of the cilia and thickening of the bronchial mucus. Regular smoking leads to difficulty breathing, chronic coughing and congestion.
There is also an important peculiarity at the level of the so-called cellular immune defense – those parts of our immune system that are represented by special cells:
Smoking reduces the number of “natural killer cells” (NK cells).
These are special defense cells that belong to the lymphocytes, which in turn are a subgroup of white blood cells. Their task is to recognize and kill abnormal cells such as cancer cells or cells infected by viruses, hence killer cells.
Healthy people have 5-15% NK cells in peripheral mononuclear blood cells. The immunological activity of these NK cells is reduced in smokers, which has an adverse effect on the frequency of respiratory infections caused by viruses, in particular.
Which possibilities result from the intake of probiotics?
A Japanese-Italian research group has shown that the administration of Lactobacillus casei has a positive effect on the initially reduced NK activity in smokers.
Lactobacillus casei belongs to those bacteria that occur naturally in the digestive tract. It is a gram-positive rod-shaped bacterium which belongs to the smaller Lactobacillus species. These rod bacteria usually have rounded corners and an average diameter of 0.9 µm and a length of 2 µm.
Lactobacillus casei plays an important role in the production of hard and semi-hard cheeses. A corresponding preparation containing viable lactobacilli is called probiotic.
After 3 weeks, probiotics increased the activity of NK cells by 9%.
Turn on the turbo!
For one study, researchers administered 73 healthy smokers either a probiotic with Lactobacillus casei or a placebo product without active ingredient over a period of 3 weeks. After 3 weeks, the activity of NK cells in the probiotics group increased significantly from 17% to 26%. In the placebo group, the increase in activity was significantly lower (an increase from 8.4 % to 10.5 %).
Another positive side effect of taking probiotics was the reduced sensation of nausea and stomach pain. However, the exact mechanisms behind the positive effect on the upper digestive system will still be the goal of further studies. Especially for athletes, however, there are already promising findings here.
The research team assessed the results very positively. They suggest that regular administration of suitable probiotics by increasing the activity of NK cells could strengthen the resistance to infection in the respiratory tract of smokers and thus improve their general state of health.
