生长猪结肠乳酸菌菌群的昼夜节律性变化

Circadian rhythm of lactic acid bacteria in colon of growing pigs

摘要:

【目的】本文旨在研究生长猪在24 h内结肠乳酸菌的多样性变化、丰富度变化与节律性变化。【方法】选取6头装有结肠瘘管的“杜×长×大”三元杂交生长猪，于清晨6:00开始，每隔3 h连续采集一天内生长猪的结肠食糜，提取DNA，用乳酸菌特异性引物进行高通量测序，在属和种水平上分析结肠乳酸菌菌群丰度与节律性变化。【结果】生长猪结肠乳酸菌在24 h内Chao1和Simpson指数发生显著性变化(P<0.05)；属水平上Lactobacillus相对丰度最高，一天内在6:00时相对丰度最低，为94.15%，18:00时相对丰度最高，为97.46%；种水平上Lactobacillus johnsonii相对丰度最高，一天内在3:00时相对丰度最低，为47.66%，18:00时相对丰度最高，为71.59%，Lactobacillus reuteri丰度次之。生长猪结肠乳酸菌中46个核心OTU具有节律性，均为Lactobacillus；而在种水平上Lactobacillus gasseri、Lactobacillus johnsonii、Lactobacillus sp. KC45a和Lactobacillus reuteri显现出节律性(P<0.05)。【结论】生长猪结肠乳酸菌在24 h内多样性发生显著性变化，在种水平上显现出节律性，丰富了我们对猪肠道微生物昼夜节律的了解。

Abstract:

[Objective] The present study aims to investigate the richness, diversity, and rhythm of lactic acid bacteria in the colon of growing pigs within 24 h. [Methods] The colonic contents from 6 growing pigs with colon fistula were collected every 3 h within 24 h starting from 6:00. The DNA of colonic bacteria was extracted for PCR which was performed with the primers specific to lactic acid bacteria. The abundance and rhythm of intestinal lactic acid bacteria at genus and species levels were analyzed via high-throughput sequencing. [Results] The Chao1 and Simpson indexes of intestinal lactic acid bacteria in growing pigs changed significantly within 24 h (P<0.05). Lactobacillus was the dominant genus in total lactic acid bacteria, with the lowest relative abundance of 94.15% at 6:00 and the highest relative abundance of 97.46% at 18:00. Lactobacillus johnsonii was the most dominant species with the lowest relative abundance of 47.66% at 3:00 and the highest relative abundance of 71.59% at 18:00. Lactobacillus reuteri took the second place in the relative abundance at the species level. Forty-six core OTUs of the lactic acid bacteria in the colon of growing pigs showed circadian rhythm, all of which belonged to Lactobacillus. At the species level, Lactobacillus gasseri, Lactobacillus johnsonii, Lactobacillus sp. KC45a and Lactobacillus reuteri showed circadian rhythm (P<0.05). [Conclusion] The richness and diversity of lactic acid bacteria in the colon of growing pigs changed significantly within 24 h, showing circadian rhythm at the species level. This study enriches our understanding on the circadian rhythm of intestinal microbiota in pigs.