A balanced microbiota is a main prerequisite for the host's health. The aim of the present work was to develop defined pig microbiota (DPM) with the potential ability to protect piglets against infection with Salmonella Typhimurium, which causes enterocolitis. A total of 284 bacterial strains were isolated from the colon and fecal samples of wild and domestic pigs or piglets using selective and nonselective cultivation media. Isolates belonging to 47 species from 11 different genera were identified by MALDI-TOF mass spectrometry (MALDI-TOF MS). The bacterial strains for the DPM were selected for anti-Salmonella activity, ability to aggregate, adherence to epithelial cells, and to be bile and acid tolerant. The selected combination of 9 strains was identified by sequencing of the 16S rRNA gene as Bacillus sp., Bifidobacterium animalis subsp. lactis, B. porcinum, Clostridium sporogenes, Lactobacillus amylovorus, L. paracasei subsp. tolerans, Limosilactobacillus reuteri subsp. suis, and Limosilactobacillus reuteri (two strains) did not show mutual inhibition, and the mixture was stable under freezing for at least 6 months. Moreover, strains were classified as safe without pathogenic phenotype and resistance to antibiotics. Future experiments with Salmonella-infected piglets are needed to test the protective effect of the developed DPM.

• Keywords
• bacterial consortium, gnotobiotic piglets, intestinal pathogens, pig intestinal bacteria, probiotic properties testing,
• Publication type
• Journal Article MeSH

Gnotobiotic (GN) animals with defined microbiota allow us to study host-microbiota and microbiota-microbiota interferences. Preterm germ-free (GF) piglets were mono-associated with probiotic Bifidobacterium animalis subsp. lactis BB-12 (BB12) to ameliorate/prevent the consequences of infection with the Salmonella Typhimurium strain LT2 (LT2). Goblet cell density; expression of Toll-like receptors (TLRs) 2, 4, and 9; high mobility group box 1 (HMGB1); interleukin (IL)-6; and IL-12/23p40 were analyzed to evaluate the possible modulatory effect of BB12. BB12 prevented an LT2-induced decrease of goblet cell density in the colon. TLRs signaling modified by LT2 was not influenced by the previous association with BB12. The expression of HMGB1, IL-6, and IL12/23p40 in the jejunum, ileum, and colon and their levels in plasma were all decreased by BB12, but these changes were not statistically significant. In the colon, differences in HMGB1 distribution between the GF and LT2 piglet groups were observed. In conclusion, the mono-association of GF piglets with BB12 prior to LT2 infection partially ameliorated the inflammatory response to LT2 infection.

• Keywords
• Bifidobacterium animalis subsp. lactis BB-12, Salmonella Typhimurium, Toll-like receptors, high mobility group box 1, immunodeficient host, inflammatory cytokines, intestinal barrier, mucin, tight junction proteins,
• MeSH
• Bifidobacterium animalis * MeSH
• Germ-Free Life MeSH
• Humans MeSH
• Infant, Premature MeSH
• Infant, Newborn MeSH
• Swine MeSH
• Probiotics * pharmacology   MeSH
• HMGB1 Protein * MeSH
• Salmonella typhimurium MeSH
• Toll-Like Receptors metabolism   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Infant, Newborn MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• HMGB1 Protein * MeSH
• Toll-Like Receptors MeSH