Gut Health Evaluation Using Gut Microbiome and Intestinal Alkaline Phosphatase Levels in Postweaning Diarrhoea

Postweaning diarrhoea (PWD) poses a significant threat to the swine industry by causing notable declines in productivity and mortality. Gut health diagnosis in pigs typically involves complex methods such as gut microbiome analysis, which can be costly and can require specialised skills. This study aimed to assess gut health in postweaning piglets by measuring and comparing gut microbiome profiles and levels of intestinal alkaline phosphatase (IALP) in faecal samples from pigs with and without PWD. This study revealed significant differences between the nondiarrhoea and diarrhoea groups of piglets in terms of IALP levels and gut microbiome composition. Nondiarrhoeal piglets had greater IALP levels than did diarrhoeal piglets (<i>p</i>=0.003). Additionally, faecal flora richness (observed (<i>p</i>=0.0007) and Chao1 (<i>p</i>=0.0007)) indices of the faecal microflora in the nondiarrhoeal pigs. At the phylum level, <i>Firmicutes</i> and <i>Bacteroidetes</i> were predominantly abundant in both groups, while <i>Firmicutes</i> (<i>p</i>=0.0008) and <i>Patescibacteria</i> (<i>p</i>=0.0334) showed significantly lower abundances in the nondiarrhoea group and <i>Bacteroidetes</i> (<i>p</i>=0.0003) exhibited greater abundance. The <i>Clostridia</i> class was significantly more abundant in the diarrhoea group than the nondiarrhoea group (<i>p</i>=0.0159). The diarrhoea group had a significantly greater relative abundance of the <i>Clostridiaceae</i> family than did the nondiarrhoea group (<i>p</i>=0.0007). At the genus level, the relative abundance of <i>Prevotellaceae</i> NK3B31 was significantly greater in the nondiarrhoea group than the diarrhoea group (<i>p</i>=0.0032). Moreover, the relative abundances of some pathogenic bacteria, including <i>Clostridium</i> sensu stricto (<i>Clostridiaceae</i>) 1, were significantly greater in the diarrhoea group than in the nondiarrhoea group (<i>p</i>=0.0007). IALP levels and gut microbiome diversity in faecal samples can be used to assess the gut health of nursery pigs. These results contribute to the understanding and manipulation of postweaning piglet gut health.