The development of intestinal lactic acid bacteria in piglets as determined by high-throughput sequencing

The present study investigated the development of intestinal lactic acid bacteria (LAB) in piglets by high-throughput sequencing. Fresh feces from newborn piglets were collected at the ages of 1, 2, 3, 7, 14, 21, 24, 35 and 42 days. Sequencing of DNA amplicons of bacteria in feces amplified with LAB-specific primers showed that Lactobacillus was the predominant genus with an abundance higher than 70%, but tended to decrease after weaning (p = 0.059). The abundance of Streptococcus was the second predominant genus on day 1, then decreased significantly (p < 0.05). The relative abundance of Facklamia, Bacillus and Aerosphaera increased significantly after weaning (p < 0.05). At the species level, Lactobacillus reuteri, Uncultured Lactobacillus sp. and Lactobacillus mucosae dominated on day 3. Lactobacillus reuteri was the predominant bacteria at 7, 21, 24 and 35 days of age, and Lactobacillus sp. MWBPC 1-3-1 dominated on day 42. The relative abundance of Lactobacillus vaginalis, Lactobacillus johnsonii and Lactobacillus gasseri on day 24 was significantly higher than other ages (p < 0.05). These results indicate that the structure and predominant species of LAB changed dramatically from birth to weaning, which is of great significance to explore the LAB for the health of piglets.