Combined dietary supplementation of long chain inulin and Lactobacillus acidophilus W37 supports oral vaccination efficacy against Salmonella Typhimurium in piglets

Abstract: (1) Background: Routine use of antibiotics in livestock animals strongly contributed to the creation of multidrug-resistant Salmonella Typhimurium strains (STM). Vaccination is an alternative to the use of antibiotics but often suffers from low efficacy. (2) Methods: Here we investigated whether long-chain inulin (lcITF) and Lactobacillus acidophilus W37 (LaW37) can support vaccination efficacy against STM and if changes can be seen at the level of gut microbiota. Piglets received daily supplementation until sacrifice. Animals were vaccinated on day 25 after birth one day after weaning, and animals were challenged with STM on days 52-54. (3) Results: LcITF/LaW37 enhanced vaccination efficacy by 2-fold. Diarrhea was significantly lower in lcITF/LaW37 and lcITF groups. Feed efficiency post-weaning was higher for piglets that received lcITF. The LcITF/LaW37 group was characterized by higher relative abundance of members of the family Prevotellaceae and lower relative abundance of Lactobacillaceae in feces. Although strongest microbial effects were observed post STM challenge on day 55, the transient effects of the dietary interventions were also detected in early life, on day 10 after birth, and post-weaning on day 30. (4) Conclusions: These results show that vaccination in immune-immature animals can be enhanced with functional foods and can simultaneously promote piglet health in an ingredient-dependent fashion. Effects on microbiota of the interventions were observed during stress periods only and were associated mainly with diarrhea.

摘要：(1) 研究背景：家畜常规使用抗生素是多重耐药鼠伤寒沙门氏菌（Salmonella Typhimurium，STM）菌株产生的重要诱因。疫苗接种是替代抗生素的防控方案，但往往存在接种效力低下的问题。(2) 试验方法：本研究旨在探究长链菊糖（long-chain inulin，lcITF）与嗜酸乳杆菌W37（Lactobacillus acidophilus W37，LaW37）能否提升抗STM疫苗的接种效力，并观察肠道菌群层面是否出现相应变化。试验仔猪每日接受膳食补充直至安乐处死。仔猪于出生后第25天，即断奶后1天进行疫苗接种，并于第52至54天以STM进行攻毒。(3) 试验结果：lcITF/LaW37可将疫苗接种效力提升2倍。lcITF/LaW37组与lcITF组仔猪的腹泻症状显著减轻。接受lcITF补充的仔猪断奶后饲料转化率更高。lcITF/LaW37组仔猪粪便中普雷沃氏菌科（Prevotellaceae）的相对丰度更高，而乳杆菌科（Lactobacillaceae）的相对丰度更低。尽管在STM攻毒后第55天观察到最为显著的菌群变化，但膳食干预的短暂菌群调控效应同样可在早期生命阶段（出生后第10天）以及断奶后第30天被检测到。(4) 试验结论：本研究结果表明，针对免疫不成熟个体的疫苗接种可通过功能性食品得到增强，同时可依添加成分的不同改善仔猪健康状况。本次膳食干预对肠道菌群的影响仅在应激阶段显现，且主要与腹泻症状相关。