Probiotic pretreatment is an effective non-antibiotic strategy for preventing or controlling Salmonella infections. We found that Lactobacillus johnsonii L531, isolated from the colon of a clinically healthy weaned piglet, effectively prevented infection with Salmonella enterica serovar Infantis in a pig model. Newly weaned piglets were intragastrically administered Lactobacillus johnsonii L531 at 1.0 × 1010 CFU/day for 1 week before S. Infantis challenge. Pretreatment with L. johnsonii L531 lessened the severity of diarrhea and ileal inflammation in S. Infantis-infected piglets. Lactobacilli were more abundant in the ileum than jejunum after L. johnsonii L531 pretreatment. Treatment with L. johnsonii L531 reduced the abundance of total bacteria in the ileal mucosa and the production of lipocalin 2 in the jejunum of piglets challenged with Salmonella. Both intestinal morphology and transmission electron microscopy results indicated that L. johnsonii L531 alleviated intestinal tissue damage following S. Infantis challenge, especially in the villus and endoplasmic reticulum (ER). ER stress induced by S. Infantis was attenuated by L. johnsonii L531 treatment. The number of CD4- CCR6+ T cells decreased following S. Infantis challenge, but the percentage of CCR6- IFNγ+ T cells in peripheral blood increased. In intestinal mesenteric lymph nodes, S. Infantis increased the proportion of CCR6+ IFNγ+ T cells, whereas L. johnsonii L531 induced an increase in the proportion of CD4+ CCR6+ T cells in response to S. Infantis infection. Our data thus suggest that L. johnsonii L531 contributes to the maintenance of intestinal homeostasis by modulating T-cell responses and ER stress.

中文翻译：

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约翰逊乳杆菌L531在小儿沙门氏菌感染的猪模型中的抗炎作用涉及调节CCR6 + T细胞反应和内质网应激。

益生菌预处理是预防或控制沙门氏菌感染的有效非抗生素策略。我们发现，从临床上健康的断奶仔猪的结肠中分离出的约翰逊乳杆菌L531在猪模型中有效地预防了肠炎沙门氏菌的感染。对刚断奶的仔猪在S. Infantis攻击前以1.0×1010 CFU /天的胃内施用约翰逊乳杆菌L531，持续1周。用约翰逊氏乳杆菌L531预处理可减轻感染沙门氏菌感染小猪的腹泻和回肠炎症的严重性。约翰逊氏菌L531预处理后，回肠中的乳酸杆菌比空肠更丰富。用L治疗。约翰逊L531降低了沙门氏菌攻击的仔猪回肠粘膜中细菌总数，并降低了空肠中脂蛋白2的产生。肠道形态和透射电镜结果均表明，约翰逊乳杆菌L531减轻了S. Infantis攻击后对肠道组织的损害，特别是在绒毛和内质网（ER）中。约翰逊氏乳杆菌L531处理可减轻由S. Infantis诱导的内质网应激。S.Infantis攻击后，CD4-CCR6 + T细胞数量减少，但外周血中CCR6-IFNγ+ T细胞的百分比增加。在肠系膜淋巴结中，S。Infantis增加了CCR6 +IFNγ+ T细胞的比例，而Johnsonii L531诱导了对S. Infantis感染的CD4 + CCR6 + T细胞比例的增加。