Effects of Fecal Sewage and Antibiotic Exposure Stress on the Intestinal Microflora of Weaned Tibetan Piglets

Unregulated pig farming practices expose pigs to fecal sewage and antibiotic stress, which are common health risk factors. Thus, its effects on the animals' intestinal microflora were investigated herein. In total, 2,315,563 high-quality sequences were obtained via amplitude sequencing and, after OUT clustering, the fecal sewage group was identified to have the highest number and the antibiotic exposure group the lowest. The dominant phyla of the intestinal flora in the Antibiotic exposure (Ant); Fecal sewage (Fec) and Normal (Nor) groups were Firmicutes, Bacteroidetes, Spirochaetota, and Spirochaetota. The most abundant families in the intestinal floras of the three groups were Streptococcaceae, Lactobacillaceae, Firmicutes, Bacteroidetes, and Spirochaetota. At the level of genus, Streptococcus, Lactobacillus, and Treponema were predominant. Dominant species were Porphyromonadaceae_bacterium_DJF_B175, Trepo-nemabryantii, and Treponema porcinum. Lactobacillus is the most commonly used probiotic agent and at the family level, Lactobacillaceae made up the largest proportion of Fec1; the addition of fecal supernatant increased the proportion of Lactobacillaceae in the gut microflora. At the level of genus, Streptococcus spp. accounted for the largest percentage of Ant1, and it was hypothesized that these have developed resistance to lincomycin. In summary, exposure to fecal sewage in the environment allows piglets to acquire beneficial microorganisms such as Lactobacillus, which influences their production. These findings highlight a potential solution for the usage of fecal sewage in agricultural environments.