Yu Leilei, Qiao Nanzhen, Li Tianqi, Yu Ruipeng, Zhai Qixiao, Tian Fengwei, Zhao Jianxin, Zhang Hao, Chen Wei
School of Food Science and Technology, Jiangnan University, Wuxi, China.
State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China.
PeerJ. 2019 Jun 3;7:e6963. doi: 10.7717/peerj.6963. eCollection 2019.
Aluminum contamination of water is becoming increasingly serious and threatens the health status of fish. CCFM639 was previously shown to be a potential probiotic for alleviation aluminum toxicity in Nile tilapia. Considering the significant role of the gut microbiota on fish health, it seems appropriate to explore the relationships among aluminum exposure, probiotic supplementation, and the gut microbiota in Nile tilapia and to determine whether regulation of the gut microbiota is related to alleviation of aluminum toxicity by a probiotic in Nile tilapia.
The tilapia were assigned into four groups, control, CCFM639 only, aluminum only, and aluminum + CCFM639 groups for an experimental period of 4 weeks. The tilapia in the aluminum only group were grown in water with an aluminum ion concentration of 2.73 mg/L. The final concentration of CCFM639 in the diet was 10 CFU/g. The results show that environmental aluminum exposure reduced the numbers of in tilapia feces and altered the gut microbiota. As the predominant bacterial phyla in the gut, the abundances of Bacteroidetes and Proteobacteria in aluminum-exposed fish were significantly elevated and lowered, respectively. At the genus level, fish exposed to aluminum had a significantly lower abundance of , and and a greater abundance of , , , and . When tilapia were exposed to aluminum, the administration of a probiotic promoted aluminum excretion through the feces and led to a decrease in the abundance of and . Notably, supplementation with a probiotic only greatly decreased the abundance of and .
Aluminum exposure altered the diversity of the gut microbiota in Nile tilapia, and probiotic supplementation allowed the recovery of some of the diversity. Therefore, regulation of gut microbiota with a probiotic is a possible mechanism for the alleviation of aluminum toxicity in Nile tilapia.
水体铝污染日益严重，威胁鱼类健康状况。先前研究表明，CCFM639是缓解尼罗罗非鱼铝毒性的潜在益生菌。鉴于肠道微生物群对鱼类健康的重要作用，探索尼罗罗非鱼铝暴露、益生菌补充与肠道微生物群之间的关系，并确定肠道微生物群的调节是否与益生菌缓解尼罗罗非鱼铝毒性有关，似乎是合适的。
将罗非鱼分为四组，即对照组、仅添加CCFM639组、仅添加铝组和铝+CCFM639组，实验期为4周。仅添加铝组的罗非鱼饲养在铝离子浓度为2.73 mg/L的水中。饲料中CCFM639的最终浓度为10 CFU/g。结果表明，环境铝暴露减少了罗非鱼粪便中的微生物数量，并改变了肠道微生物群。作为肠道中的主要细菌门类，暴露于铝的鱼类中拟杆菌门和变形菌门的丰度分别显著升高和降低。在属水平上，暴露于铝的鱼类中，[具体属名1]、[具体属名2]和[具体属名3]的丰度显著降低，而[具体属名4]、[具体属名5]、[具体属名6]和[具体属名7]的丰度更高。当罗非鱼暴露于铝时，补充益生菌可促进铝通过粪便排出，并导致[具体属名8]和[具体属名9]的丰度降低。值得注意的是，仅补充益生菌会大大降低[具体属名10]和[具体属名11]的丰度。
铝暴露改变了尼罗罗非鱼肠道微生物群的多样性，补充益生菌可使部分多样性得以恢复。因此，用益生菌调节肠道微生物群是缓解尼罗罗非鱼铝毒性的一种可能机制。
