Probiotics' Efficacy in Preventing Asthmatic Allergic Reaction Induced by Air Particles: An Animal Study

Abstract

Global air pollution and diesel exhaust particles (DEPs) generated by intratracheal instillation aggravate asthma. In this study, we evaluated the effect of probiotics via tracheal- or oral-route administration on allergies or asthma. We continuously perfused rats daily, using the oral and tracheal routes, with approximately 10⁶-10⁸ CFU probiotics, for 4 weeks. During this period, we used OVA-sensitized rats to build the asthma models. We orally or intratracheally administered Lactobacillus paracasei 33 (LP33) to the rats, which reduced the number of total inflammatory cells, lymphocytes, and eosinophils in the bronchoalveolar-lavage fluid, the IgE concentration, and the cytokine levels of TH2 cells, but we found no significant difference in the cytokine levels of TH1 cells. LP33 can be used to prevent asthmatic allergic reactions induced by aerosol particles. Nevertheless, the dosage form or use of LP33 needs to be adjusted to reduce the irritation of lung tissues, which may produce lesions of the trachea. We observed that DEP dosage can alleviate emphysema, and that LP33 has a substantial effect on improving or slowing allergic asthma.

Keywords: allergic disease; asthma; diesel exhaust particles; ovalbumin; probiotics.

Figure 1

Flow chart of the animal experiment: six groups of rats were orally or intratracheally administered instillation probiotics or PBS or dexamethasone for 28 days continuously. Rats were intraperitoneally injected with OVA and Al (OH)3 in PBS on days 1, 14, 21, and 28. On day 29, rats were given 1.7% OVA via intratracheal instillation for sensitization, then ultrasonic-atomizing for 30 min with 1% OVA for 5 consecutive days. On days 30, 32, and 34, rats were continuously exposed to DEPs or PBS by intratracheal administration. Within 24 of the last exposure to DEP, the rats were sacrificed. PBS, phosphate-buffered saline; alum, aluminum hydroxide; OVA, ovalbumin; DEPs, diesel exhaust particles; IP, intraperitoneal; PO, per oral; IT, intratracheal instillation.

Figure 2

Effect of (A) intratracheal and (B) oral-probiotic-Lactobacillus paracasei LP33 administration on body-weight change induced by OVA/DEP in asthmatic rats. Mean ± SD values are shown for the four groups of rats. Each group contained 8 rats. Mean statistical significance compared with asthma group using Dunnett’s t-test; ** p < 0.01, *** p < 0.001.

Figure 3

Effect of intratracheal-probiotic-Lactobacillus paracasei LP33 administration on inflammatory-cell proliferation induced by OVA/DEP in asthmatic rats: (a) total cell, (b) eosinophil, and (c) lymphocyte counts. Mean ± SD values are shown for the four groups of rats. Each group contained 8 rats. Statistical significance compared with asthma group using Dunnett t-test: * p < 0.05, ** p < 0.01, and *** p < 0.001.

Figure 4

Effect of oral-probiotic-Lactobacillus paracasei LP33 administration on inflammatory-cell proliferation induced by OVA/DEP, in asthmatic rats: (a) total cell, (b) eosinophil, and (c) lymphocyte counts. Mean ± SD values for four groups of rats. Each group contained 8 rats. Statistical significance compared with asthma group using Dunnett’s t-test: * p < 0.05, ** p < 0.01, and *** p < 0.001.

Figure 5

Effect of intratracheal-probiotic-Lactobacillus paracasei LP33 administration on cytokine levels in BALF induced by OVA/DEP, in asthmatic rats: (a) protein, (b) IL-4, and (c) TNF- α. Mean ± SD values for four groups of rats. Each group contained 8 rats. Statistical significance compared with asthma group using Dunnett’s t-test: * p < 0.05 and ** p < 0.01.

Figure 6

Effect of oral-probiotic-Lactobacillus paracasei LP33 administration on BALF cytokine-levels induced by OVA/DEP, in asthmatic rats: (a) protein, (b) IL-4, and (c) TNF-α. Mean ± SD values of four groups of rats. Each group contained 8 rats. Statistical significance compared with asthma group using Dunnett’s t-test: * p < 0.05.

Figure 7

Effect of (A) intratracheal and (B) oral-probiotic-Lactobacillus paracasei LP33 administration on serum-IgE concentrations induced by OVA/DEP, in asthmatic rats. Mean ± SD values for four groups of rats. Each group contained 8 rats. * Statistical significance compared with asthma group using Dunnett’s t-test: * p < 0.05.

Figure 8

Effect of intratracheal-probiotic-Lactobacillus paracasei LP33 administration on histopathological changes in lung tissues induced by Group C (OVA-DEP group) in asthmatic rats: (A) granuloma, multiple localized, mild, lung; (B) emphysema, alveolar cavity, multiple local, moderate, lung; (C) emphysema, alveolar cavity, multiple local, moderate, lung; (D) granuloma, multiple localized, mild, lung. Magnification for all: 100×.

Figure 9

Effect of oral-probiotic-Lactobacillus paracasei LP33 administration on histopathological changes in lung tissues induced by Group E (PO Probiotics group) in asthmatic rats: (A) infiltration, monocytes, spread, mild, lung; (B) emphysema, alveolar cavity, multiple local, moderate, lung; (C) granuloma, multiple local, moderate, lung; (D) granuloma, multiple localized, mild, lung. Magnification: 100×.