Laboratory of Aquaculture Nutrition and Environmental Health, School of Life Sciences, East China Normal University, Shanghai, China.
School of Basic Medical Sciences, Shanghai University of Traditional Chinese Medicine, Shanghai, China.
Front Immunol. 2021 Nov 26;12:766401. doi: 10.3389/fimmu.2021.766401. eCollection 2021.
Probiotic administration is a potential strategy against enteric pathogen infection in either clinical treatment or animal nutrition industry, but the administration duration of probiotics varied and the underlying mechanisms remain unclear. A strain (YC) affiliated to , a commonly used probiotic, was isolated from fish gut and the potential role of YC against was detected in zebrafish. We found that 3- or 4-week YC administration (YC3W or YC4W) increased the resistance against while 1- or 2-week treatment (YC1W or YC2W) did not. To determine the possible reason, intestinal microbiota analysis and RNAseq were conducted. The results showed that compared with CON and YC1W, YC4W significantly increased the abundance of short-chain fatty acids (SCFAs) producing bacteria and elevated the gene expression of . Higher butyrate content and enhanced expression of IL1β were subsequently found in YC4W. To identify the causal relationship between butyrate and the higher pathogen resistance, different concentrations of sodium butyrate (SB) were supplemented. The results suggested that 10 mmol/kg SB addition mirrored the protective effect of YC4W by increasing the production of IL-1β. Furthermore, the increased IL-1β raised the percentage of intestinal neutrophils, which endued the zebrafish with resistance. knockdown of intestinal eliminated the anti-infection effect. Collectively, our data suggested that the molecular mechanism of probiotics determined the administration duration, which is vital for the efficiency of probiotics. Promoting host inflammation by probiotic pretreatment is one potential way for probiotics to provide their protective effects against pathogens.
益生菌的使用是一种针对肠道病原体感染的潜在策略，无论是在临床治疗还是动物营养行业，但是益生菌的使用时间长短不同，其潜在机制仍不清楚。YC 是一种常见益生菌的菌株，它从鱼类肠道中分离出来，YC 对 的潜在作用在斑马鱼中得到了检测。我们发现，YC 连续 3 周或 4 周（YC3W 或 YC4W）的使用增加了对 的抵抗力，而连续 1 周或 2 周（YC1W 或 YC2W）的使用则没有。为了确定可能的原因，我们进行了肠道微生物群分析和 RNAseq。结果表明，与 CON 和 YC1W 相比，YC4W 显著增加了短链脂肪酸（SCFAs）产生菌的丰度，并上调了 的基因表达。随后发现，YC4W 中的丁酸含量更高，IL1β 的表达增强。为了确定丁酸与更高的病原体抗性之间的因果关系，我们添加了不同浓度的丁酸钠（SB）。结果表明，10 mmol/kg SB 的添加模拟了 YC4W 的保护作用，增加了 IL-1β 的产生。此外，增加的 IL-1β 提高了肠道中性粒细胞的比例，使斑马鱼具有了 抗性。肠道 的 敲低消除了抗感染作用。总之，我们的数据表明，益生菌的分子机制决定了使用时间，这对益生菌的效率至关重要。益生菌预处理促进宿主炎症是益生菌提供针对病原体的保护作用的一种潜在途径。
