Diarrhea is a major cause of piglet mortality, often reported associated with maternal gut bacterial communities (microbiota). Maternal supplementation with probiotic Clostridium butyricum during late gestation showed to reduce piglet diarrhea during the suckling period. This study thereby investigated the effects of probiotic supplementation on sow gut (feces) microbiota and their potential microbial metabolisms.

Sow and litter performances, including milk compositions and incidences of piglet diarrhea, were recorded from farrowing to weaning of control- supplemented vs. probiotic-supplemented sows. Fecal samples from sows classified as before (Cb=17) and after (Ca=17) probiotic supplementation were analyzed using 16S rRNA gene sequencing and 16S rRNA qPCR, following bioinformatic analyses for alpha-beta diversity, quantitative microbiota, LEfSe (Linear discriminant analysis Effect Size) taxon biomarker analysis, potential microbial metabolism profiles, and statistical correlations with microbial species and clinical data performances.

Probiotic-supplemented sows demonstrated the greater average piglets born alive and lower mummified fetuses (P > 0.05), and the statistical higher protein and casein contents in their colostrum (P < 0.05). Following microbiota analyses, no significant difference was observed in operational taxonomic units (OTUs), Chao1, and Shannon alpha-diversity indices between Cb and Ca samples. Nevertheless, Ca sows exhibited higher relative abundances of Clostridium, SMB53, g_Turicibacter, Treponema, Bacillus, Enterococcus and Lactobacillus, while the lower abundances of Oscillospira, Prevotella, Phascolarctobacterium and Ruminococcus, compared with Cb sows. This highlighted that after the probiotic supplementation showed the sow gut microbiota more abundances of potentially beneficial bacteria, including the supplemented probiotic C. butyricum, g_Bacillus, g_Enterococcus and g_Lactobacillus, for instances. The finding was consistent with the LEfSe (Linear discriminant analysis Effect Size) taxon biomarker analysis for the Ca group. Several microbial related metabolic pathways in sow feces were altered after probiotic supplement, particularly relevant to amino acid and short-chain fatty acid metabolisms (i.e., propanoate and butanoate), xenobiotics biodegradation and lipid metabolism. Supportively, the gut microbiota changes of Ca sows might associate with improved sow performance and milk metabolomic profile.

The maternal probiotic C. butyricum supplementation during late gestation and lactation showed the improved sows’ intestine, milk components, and the reduced piglet diarrhea cases. This helps to understand and support the probiotic supplementation in sows.