Postbiotic effects of Lactobacillus fermentate on intestinal health, mucosa-associated microbiota, and growth efficiency of nursery pigs challenged with F18+Escherichia coli

This study determined the supplemental effects of Lactobacillus fermentate (LBF, Adare Biome, France) on intestinal health and prevention of postweaning diarrhea caused by F18+Escherichia coli in nursery pigs. Sixty-four weaned pigs (6.6 ± 0.7 kg body weight) were allotted in a randomized complete block design to four treatments: NC: no challenge/no supplement; PC: E. coli challenge/no supplement; AGP: E. coli challenge/bacitracin (30 g/t feed); and PBT: E. coli challenge/LBF (2 kg/t feed). Bacitracin methylene disalicylate (BMD) was used as a source of bacitracin. On day 7, challenged groups were orally inoculated with F18+E. coli (2.4 × 1010 CFU), whereas NC received sterile saline solution. Growth performance was analyzed weekly, and pigs were euthanized at the end of 28 d feeding to analyze intestinal health. Data were analyzed using the Mixed procedure of SAS 9.4. During the post-challenge period, PC tended to decrease (P = 0.067) average daily gain (ADG) when compared with NC, whereas AGP increased (P < 0.05) when compared with PC; PBT tended to increase (P = 0.081) ADG when compared with PC. The PC increased fecal score (P < 0.05) during day 7 to 14 when compared with NC, whereas AGP decreased it (P < 0.05) during day 14 to 21 when compared with PC. The PC increased (P < 0.05) protein carbonyl, crypt cell proliferation, and the relative abundance of Helicobacter rodentium when compared with NC. However, AGP decreased (P < 0.05) crypt cell proliferation and H. rodentium and increased (P < 0.05) villus height, Bifidobacterium boum, Pelomonas spp., and Microbacterium ginsengisoli when compared with PC. The PBT reduced (P < 0.05) crypt cell proliferation and H. rodentium and increased (P < 0.05) Lactobacillus salivarius and Propionibacterium acnes when compared with PC. At the genus level, AGP and PBT increased (P < 0.05) the alpha diversity of jejunal mucosa-associated microbiota in pigs estimated with Chao1 richness estimator when compared with PC. Collectively, F18+E. coli reduced growth performance by adversely affecting microbiota and intestinal health. The LBF and BMD improved growth performance, and it was related to the enhanced intestinal health and increased diversity and abundance of beneficial microbiota in pigs challenged with F18+E. coli.Newly weaned pigs are susceptible to multiple stressors that may lead to postweaning diarrhea, thereby causing significant economic losses in the swine industry. Enterotoxigenic Escherichia coli strains are the major agents causing diarrhea in newly weaned pigs. Subtherapeutic antibiotics have been employed by producers around the world to mitigate this issue. However, the use of antibiotics as growth promoters has become a public health concern because of microbial resistance. This study used Lactobacillus fermentate (LBF) as a postbiotic to help maintain healthy microbiota on the intestinal mucosa and to prevent postweaning diarrhea caused by E. coli F18+. Therefore, the aim of this study was to evaluate the effects of dietary supplementation of LBF on intestinal microbiota, intestinal health, and prevention of postweaning diarrhea caused by a challenge with E. coli F18+ in newly weaned pigs. Our model confirmed that the E. coli F18+ reduced growth performance by causing diarrhea, disruption of the microbiota composition, and increased immune response and oxidative stress in the small intestine of newly weaned pigs. Lactobacillus fermentate improved growth performance, and it was related to enhanced intestinal health and increased microbiota diversity in E. coli F18+-challenged pigs.