Effect of a Synbiotic "Probiotical®/Bactecal® " in Asthma

It is a randomized double blind placebo control study. One hundred severe asthmatic patients will receive "Probiotical ®/Bactecal®" each day during 3 months and will be evaluated before and 1-3-6 months after in order to assess the impact of the synbiotic on the lung function, the exhaled nitric oxide value, the inflammatory blood and sputum profiles, the bronchial reactivity, the microvascular health and the quality of life and asthma control. The hypothesis is that, as these patients are not optimally controlled, the synbiotic could have an impact by decreasing the inflammation state at local and systemic level and then improve the quality of life and the asthma control. Indeed, synbiotic have been shown to possess beneficial effects on the immune system.

Thirty percent of asthmatic patients are not well controlled even with an optimal treatment. There is then a need for new therapeutics allowing a better asthma control. Synbiotic (association of probiotics and prebiotics) have been shown to have anti-inflammatory properties as well as immunomodulatory activities. Moreover, synbiotic appeared to be very well tolerated and safe. One hundred severe asthmatic patients (ACQ\> 1.5 and beclomethasone \> 200 µg per day) will receive "Probiotical ®/Bactecal®" (3 pills a day, content: Lactobacillus, Bifidobacterium et Streptococcus thermophilus, 18 billion of bacteria per pill) or a placebo during 3 months. They will be evaluated before and 1-3-6 months after the first administration and different tests will be realized: * lung function tests (spirometry, lung volumes, diffusing capacity) * exhaled nitric oxide value (FeNo, linked to airway eosinophilia) * blood tests: leucocyte count, c reactive protein, fibrinogen. Plasma and serum will be kept for inflammatory mediators measurements. * sputum induction: leucocyte count and mediators measurements using the sputum supernatant and sputum cells. * bronchial reactivity (bronchial challenge test) * microvascular health: to assess the glycocalyx state, see: http://glycocheck.com/ for details. * questionnaires: asthma control test (ACT), asthma control questionnaire (ACQ), asthma quality of life questionnaire (AQLQ ).