Roles of probiotics in regulating serum ghrelin levels and protecting pulmonary function of children with acute lung injury
Objective 
To investigate the regulatory effects of probiotics on ghrelin and their protective effects on pulmonary function of children during acute lung injury. 
 
 
Methods 
Fifty children with acute lung injury were recruited form Henan Provincial People's Hospital during 2010 to 2013 and randomly divided into two groups. In addition to regular therapy, those who received probiotics treatment were set up as the probiotics treatment group and the others were considered as the control group. Levels of ghrelin, surfactant protein A(SP-A), TNF-α and IL-6 in serum samples were measured before and 10 days after the corresponding treatments. Each patient was analyzed by pulmonary function test and echocardiography. The volume to peak expiratory flow (VPEF), ratio of time to reach peak tidal expiratory flow to total expiratory time (TPTEF/TE), mean arterial pressure (MAP) and pulmonary artery pressure (PAP) were recorded for statistical analysis. 
 
 
Results 
The levels of SP-A, TNF-α and IL-6 in serum samples from the probiotics treatment group were decreased on day 10 as compared with those of the control group [(195.9±54.3) ng/ml vs (245.5±56.4) ng/ml, (382.0±56.4) pg/ml vs (440.7±46.8) pg/ml, (221.5±62.6) pg/ml vs (303.5±83.9) pg/ml; P<0.05]. Children from the probiotics treatment group showed higher values of VPEF and TPTEF/TE on day 10 as compared with those without probiotics treatment [(25.3±4.5) ml vs (23.8±4.6) ml, (29.5±4.3) % vs (26.8±4.7) %; P<0.05]. Treatment of children with probiotics increased MAP and decreased PAP [(74.5±6.7) mmHg vs (71.9±6.9) mmHg, (25.5±6.4) mmHg vs (29.1±6.2) mmHg]. The levels of ghrelin in patients received probiotics treatment were higher than those of children without probiotics treatment [(329.3±49.6) pg/ml vs (296.6±48.5) pg/ml]. The levels of ghrelin showed negative correlations with the levels of SP-A, TNF-α, IL-6 and PAP on day 10, but positive correlations with TPTEF/TE and MAP (P<0.05). 
 
 
Conclusion 
Use of probiotics to children with acute lung injury could regulate the level of ghrelin, alleviate the inflammation of lungs and improve the recovery of lung function and circulation. Therefore, probiotics treatment had positive effects on the protection of pulmonary function. 
 
 
Key words: 
Probiotics; Acute lung injury; Ghrelin; Inflammatory factor