Clostridium butyricum Prevents Diarrhea Incidence in Weaned Piglets Induced by Escherichia coli K88 through Rectal Bacteria–Host Metabolic Cross-Talk.

Simple Summary: Following weaning, piglets exhibit an immature immune system, reduced capacity to digest and absorb nutrients, and encounter diverse stressors that significantly compromise their overall health. The supplementation of probiotics in animal feed has proven to be a beneficial strategy for enhancing the welfare of livestock and poultry. The findings of this research demonstrate that supplementing the diet with 5 × 10⁸ CFU/kg of Clostridium butyricum enhances fecal microflora diversity and richness through the modulation of specific metabolites such as L-aspartic acid, 5-hydroxyindole-3-acetic acid, stearic acid, and adipic acid. This mechanism contributes to a reduction in the incidence of diarrhea in weaned piglets triggered by E. coli K88. Consequently, the study outcomes offer both empirical evidence and theoretical support for the utilization of Clostridium butyricum in combatting diarrhea in piglet rearing. This study aimed to evaluate the effects of Clostridium butyricum (C. butyricum) on the prevention of the diarrhea rates and growth performances of weaned piglets induced by Escherichia coli K88 (E. coli K88). Twenty-four weaned piglets (6.92 ± 0.11 kg) were randomly assigned to one of three treatment groups for a period of 21 days. Each group consisted of eight pigs, with each pig being housed in an individual pen. Group I received the control diet along with normal saline, Group II received the control diet along with E. coli K88, and Group III received the control diet supplemented with 5 × 10⁸ CFU/kg of C. butyricum and E. coli K88. We examined alterations in rectal microbiota and metabolites, analyzed the incidence of diarrhea, and investigated the interactions between microbiota and metabolites through the application of Illumina MiSeq sequencing and liquid chromatography–mass spectrometry. The results showed that, from days 14 to 21, the diarrhea incidence in Group III decreased significantly by 83.29% compared to Group II (p < 0.05). Over the entire experimental duration, the average daily feed intake of Group III decreased significantly by 11.13% compared to Group I (p < 0.05), while the diarrhea incidence in Group III decreased by 71.46% compared to Group II (p < 0.05). The predominant microbial flora in the rectum consisted of Firmicutes (57.32%), Bacteroidetes (41.03%), and Proteobacteria (0.66%). Administering E. coli K88 orally can elevate the relative abundance of Megasphaera (p < 0.05). Conversely, the supplementation of C. butyricum in the diet reduced the relative abundance of Megasphaera (p < 0.05), while increasing the relative abundance of unclassified_f_Lachnospiraceae (p < 0.05). Rectal metabolomics analysis revealed that supplementing C. butyricum in the feed significantly altered the amino acids and fatty acids of the piglets infected with E. coli K88 (p < 0.05). The correlation analysis showed that the occurrence of diarrhea was inversely related to adipic acid (p < 0.05) and positively associated with (5-hydroxyindol-3-YL) acetic acid and L-aspartic acid (p < 0.05). Prevotella_1 exhibited a negative correlation with octadecanoic acid (p < 0.05). Prevotellaceae_UCG-005 showed a negative correlation with (5-hydroxyindol-3-YL) acetic acid (p < 0.05). The findings from this research study aid in probiotic development and the enhancement of healthy growth in weaned piglets. [ABSTRACT FROM AUTHOR]