Microecological preparation could relieve Enterotoxigenic Escherichia coli (ETEC) K88-induced diarrhea in piglets, but which bacteria play a key role and the mitigation mechanism have not been fully clarified. In this study, 36 male mice were randomly divided into six groups (CON, K88, BK (Bifidobacterium longum + K88), LK (Lactobacillus plantarum + K88), PK (Pediococcus acidilactici + K88), and MK (mixed strains + K88)) to explore the prevention mechanisms. Three probiotic strains and their mixtures (TPSM) significantly relieved the weight loss and restored the ratio of villus height to crypt depth in the jejunum. Except for Bifidobacterium longum, other strains significantly decreased interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α) in mice serum. The TPSM treatment significantly downregulated the mRNA expression of the inflammatory cytokines and the Toll-like receptor and downstream gene (TLR4, MyD88, NF-κB) in jejunum induced by ETEC. Furthermore, the TPSM could restore dysbiosis of the intestinal microbiota caused by ETEC. The intestinal microbiota analysis demonstrated that Bifidobacterium longum enriched the Bifidobacterium genus (p < 0.05), Lactobacillus plantarum enriched the Lactobacillus genus (p < 0.05), Pediococcus acidilactici enriched the Coriobacteriaceae_UCG-002 and Christensenellaceae_R-7_group genus (p < 0.05), mixed bacteria enriched the Akkermansia genus (p < 0.05), but ETEC enriched the Desulfovibrio genus (p < 0.05). Meanwhile, the starch and sucrose metabolism, galactose and fructose metabolism, mannose metabolism and ABC transporters were increased with probiotics pre-treatment (p < 0.05). To sum up, the microecological preparation alleviated ETEC-induced diarrhea by regulating the immune response, rebalancing intestinal microbiota and improving carbohydrate metabolism.

Various countries and organizations call for banning the use of antibiotic growth promoters (AGPs) as prophylaxis and for growth promotion in the livestock industry. Hence, seeking a substitute for antibiotics is strongly required by the livestock industry to maintain the productivity level and profits. Probiotics could represent one viable solution because of their beneficial effects on host health and maintaining the intestinal microbiota balance. In the present study, we aimed to isolate bacterial strains with probiotics properties from JinHua pig (a Chinese native pig breed) gastrointestinal tract that have antagonistic activity against to common disease-causing bacteria on farms. The four most potent strains were isolated (PP31, BA11, BA40, BV5) by the agar well diffusion method and further characterized by acid, bile salt, trypsin tolerance, whole genome sequencing (WGS), and suppressing Clostridium perfringens adhesion to IPEC-J2 cells. According to these results, BA40 had the highest number and variety of probiotic secondary metabolic secretion genes and capacity to exclude the attachment of Clostridium perfringens to IPEC-J2 cells as same as PB6. The animal experiment in vivo illustrated that BA40 and PB6 could reduce the phenomenon induced by Clostridium perfringens challenge of body weight loss, colon length decrease, pro-inflammatory cytokine increase, and Clostridium perfringens and Escherichia coli increase. The present study provides evidence that BA40 could represent a novel probiotic candidate as PB6, which exhibited some probiotic features and mitigated the burden of Clostridium perfringens associated gut disease.

Background: The early-life gut microbiota plays a critical role in programming intestinal barrier function and immune homeostasis, with profound implications for long-term host health. However, the effects of early-life compound probiotic intervention on the maturation of intestinal barrier function and the underlying molecular mechanisms remain incompletely understood, particularly in large-animal models relevant to human physiology. Methods: In this preclinical study, 3627 neonatal piglets—a well-established translational model for human infant gut development—were orally administered a novel compound probiotic formulation comprising Bifidobacterium longum subsp. infantis BZ, Lactobacillus plantarum LZ, and Pediococcus acidilactici PZ during early life. A total of 1512 fecal samples collected at seven time points from birth to day 180 were analyzed by 16S rRNA sequencing, and 525 samples from three developmental windows (days 10, 25, and 70) were subjected to LC-MS-based metabolomics. The candidate metabolite indole-3-lactic acid (ILA) was further mechanistically validated in a DSS-induced colitis mouse model and in IPEC-J2 cells. Results: Early-life probiotic intervention significantly enhanced intestinal barrier integrity, as evidenced by improved intestinal morphology and upregulated expression of tight junction proteins—zonula occludens-1 (ZO-1), occludin (OCLN), and Claudin-1 (CLDN1)—in the jejunum (p < 0.05). Notably, intervention at birth was more effective than post-weaning administration, and two administrations (birth + weaning) yielded superior outcomes compared with a single administration (p < 0.05). Microbiome analysis revealed enhanced microbial diversity and enrichment of beneficial genera during the juvenile-to-adult transition (p < 0.05). Metabolomic profiling identified ILA as a signature metabolite consistently elevated by probiotic supplementation. Conclusions: These findings provide evidence that early-life compound probiotic intervention is associated with improved intestinal barrier maturation, with ILA identified as a key candidate metabolite that may mediate this effect, as supported by functional validation in murine and cellular models. This provides a mechanistic rationale for probiotic-based strategies to support intestinal health in human infants during critical developmental windows.