Anti-allergic effects of Lactobacillus acidophilus La28 and L. plantoplantum LP45 in mice

Abstract:

[Objective] To compare the allergic effects of Lactobacillus acidophilus La28 and L. plantoplantum LP45 against allergic dermatitis and allergic asthma in mice, and to analyze the strain-specific differences in related immune regulatory effects.[Methods] In order to study atopic dermatitis, we randomly assigned 40 mice into control group, model group, La28 group, and LP45 group. Except those in the control group, the mice in other three groups were treated with 2,4-dinitrofluorobenzene to induce ear swelling and dermatitis. The mice in La28 group and LP45 group received 5×10⁸ CFU/mL corresponding bacteria by intragastric administration every day for three weeks. We then measured the ear swelling rate and skin lesion score in each group, observed the pathological changes of skin, and determined the levels of interleukin-4 (IL-4) and interleukin-13 (IL-13) in the skin. To study allergic asthma, we treated mice in the other three groups except the control group with ovalbumin and aluminum hydroxide adjuvant to induce asthma. The mice in La28 group and LP45 group were fed with 5×10⁸ CFU/mL corresponding bacteria every day for four weeks. We then evaluated the asthma symptoms of mice in each group, examined the pathological changes in the lung tissue, and determined the levels of IL-4, IL-13, and interleukin-17 (IL-17) in the lung tissue.[Results] La28 and LP45 significantly relieved ear swelling and skin damage, significantly reduced IL-4 secretion, and slightly lowered the IL-13 level in the mice with allergic dermatitis. La28 and LP45 alleviated asthma symptoms. LP45 mitigated the pathological injury of the lung tissue, reduced inflammatory cell infiltration, and significantly down-regulated the levels of IL-4, IL-13, and IL-17 in the lung tissue. La28 significantly reduced the IL-13 secretion while insignificantly lowered the levels of IL-4 and IL-17.[Conclusion] The two Lactobacillus strains, especially LP45, can regulate the immune function and repair the damaged tissues to relieve atopic dermatitis and asthma in mice.

Key words:allergy;Lactobacillus;dermatitis;asthma;cytokines