Changes in faecal bacteria during fattening in finishing swine.

Body fat accumulation in mice and human is linked to the percentage of Firmicutes and Bacteroidetes, two bacterial phyla dominant in the large intestine. However, little is known about the relationship between the composition of the gut microbiota and fattening in pig. This study aimed to investigate the abundance of Firmicutes, Bacteroidetes, and Bacteroides, which is the major genus within Bacteroidetes, in porcine faeces during fattening. Ten 4-month-old crossbred pigs were given free access to commercial feed for fattening and water for 14 weeks. Daily feed intake and body weight were measured every 2 weeks. Faecal samples were collected at 0, 4, 8, and 14 weeks, and plasma samples were collected every 2 weeks. Daily feed intake increased until 8 weeks, and then decreased. Body weight increased with fattening during the experimental period. Feed efficiency showed high values at 0-4 and 6-8 weeks. The level of Firmicutes increased (P < 0.05), whereas those of Bacteroides and Bacteroidetes decreased (P < 0.05) with fattening. The total short chain fatty acid content in the faeces increased (P < 0.05) with fattening until 8 weeks and then decreased (P < 0.05) at 14 weeks. There were no significant relationships between the level of Firmicutes and feed intake or plasma leptin concentration. The levels of Bacteroidetes and Bacteroides correlated with feed intake, body weight, and plasma leptin or plasma urea nitrogen (PUN) concentration. Our results suggested that the level of Firmicutes increased and those of Bacteroidetes and Bacteroides decreased with increase in feed intake and body weight, similar to previous results obtained for mice and human. However, energy extraction from feed was not influenced by compositional alteration of gut flora, because daily gain and feed efficiency did not show high values towards the end of the fattening period. Manipulating the gut microbiota might help improve fattening performance, although further studies are necessary to understand the relationships between the composition of gut microbiota and energy absorption.

Immunoregulatory effects triggered by immunobiotic Lactobacillus jensenii TL2937 strain involve efficient phagocytosis in porcine antigen presenting cells.

BACKGROUND: Immunobiotic Lactobacillus jensenii TL2937 modulates porcine mononuclear phagocytes from Peyer's patches (PPMPs) and induces a differential production of pro- and anti-inflammatory cytokines in response to Toll-like receptor (TLR)-4 activation. In view of the important role played by phagocytosis in the activation of antigen presenting cells (APCs), the aim of the present work was to examine the interaction of TL2937 with porcine PPMPs focusing on phagocytosis. In addition, this study aimed to investigate whether the effects of L. jensenii TL2937 in porcine blood monocyte-derived dendritic cells (MoDCs) are similar to those found in PPMPs considering that MoDCs do not recapitulate all functions of mucosal APCs. RESULTS: Studies showed a high ability of porcine CD172a(+) PPMPs to phagocytose L. jensenii TL2937. Interestingly, our results also revealed a reduced capacity of the non-immunomodulatory L. plantarum TL2766 to be phagocytosed by those immune cells. Phagocytosis of L. jensenii TL2937 by porcine PPMPs was partially dependent on TLR2. In addition, we demonstrated that TL2937 strain was able to improve the expression of IL-1ß, IL-12 and IL-10 in immature MoDCs resembling the effect of this immunobiotic bacterium on PPMPs. Moreover, similarly to PPMPs those immunomodulatory effects were related to the higher capacity of TL2937 to be phagocytosed by immature MoDCs. CONCLUSIONS: Microbial recognition in APCs could be effectively mediated through ligand-receptor interactions that then mediate phagocytosis and signaling. For the immunobiotic strain TL2937, TLR2 has a partial role for its interaction with porcine APCs and it is necessary to investigate the role of other receptors. A challenge for future research will be advance in the full understanding of the molecular interactions of immunobiotic L. jensenii TL2937 with porcine APCs that will be crucial for the successful development of functional feeds for the porcine host. This study is a step in that direction.

Effects of oral administration of Butyrivibrio fibrisolvens MDT-1 on the development and healing of atopic dermatitis in NC/Nga mice.

The purpose of this study was to evaluate the effects of oral administration of Butyrivibrio fibrisolvens MDT-1 (MDT-1) on mite antigen-induced atopic dermatitis (AD) in NC/Nga mice. When administration of the freeze-dried cells of MDT-1 was initiated one week before mite-antigen swabbing, the development of AD-like skin lesions was alleviated. The cell homogenate and membrane fraction had similar effects, showing that cell components are effective. Freeze-dried cells were found to be replaceable by the crude lipopolysaccharide extracted from MDT-1. Alleviation of AD was concomitant with a decrease in the serum IgE level. Determination of cytokines produced by Peyer's patch cells showed that MDT-1 administration increased IL-12, tended to increase IFN-γ, and tended to decrease IL-10, but did not affect IL-4. When MDT-1 was administered after the skin lesions had progressed, the symptoms were ameliorated, suggesting that MDT-1 has AD-healing effects. MDT-1 was as effective as prednisolone, but different from prednisolone in that MDT-1 showed no detectable side effects such as body weight loss. We previously reported that MDT-1 administration prevented and alleviated colorectal cancer, sarcoma, and enterocolitis in mice. Taken together, MDT-1 might be beneficial for maintaining the health of pet animals and humans.

Dietary sphingomyelin alleviates experimental inflammatory bowel disease in mice.

The effect of dietary sphingomyelin (SM) on inflammatory bowel disease (IBD) induced with dextran sodium sulfate (DSS) was examined in mice. Although the severity of IBD as expressed by the disease activity index (DAI) markedly increased with DSS administration, feeding a diet containing SM lowered the DAI value significantly. Myeloperoxidase (MPO) activity in colonic tissue also increased with DSS administration, suggesting the development of inflammation. Because simultaneous administration of SM with DSS prevented the MPO activity increase, we concluded that SM could suppress the development of inflammation. These results provide novel evidence that dietary supplementation with SM can alleviate the symptoms of IBD in mice. Dietary SM also increased the amount of IgA in the large intestine, suggesting that SM promotes IgA secretion into the large intestine. These results suggest that the mechanism of IBD mitigation by SM is complex and involves the immune system.

Draft Genome Sequence of the Immunobiotic Strain Lactobacillus jensenii TL2937.

The genome of the immunomodulatory strain Lactobacillus jensenii TL2937 is described here. The draft genome has a total length of 1,678,416 bp, a G+C content of 34.3%, and 1,470 predicted protein-coding sequences. The genome information will be useful for gaining insight into the immunomodulatory properties of the TL2937 strain in the porcine host.

Draft Genome Sequence of Lactobacillus plantarum TL2766, a Strain with the Ability To Ferment Wakame.

The genome sequence of Lactobacillus plantarum TL2766, a strain with the ability to ferment wakame (Undaria pinnatifida), is described here. The reads were assembled into contigs, with a total size of 3,310,195 bp. The genome information will be useful for further specific genetic studies of this strain and for its biotechnological applications.

Effect of oral administration of Butyrivibrio fibrisolvens MDT-1, a gastrointestinal bacterium, on 3-methylcholanthrene-induced tumor in mice.

Butyrivibrio fibrisolvens MDT-1 was evaluated for use as a probiotic to prevent tumor formation. Oral administration of MDT-1 (10(9) cfu/dose, 3 times a wk for 15 wk) delayed the onset of tumors induced by 3-methylcholanthrene and also reduced tumor incidence in mice. Furthermore, the numbers of natural killer (NK) and NKT cells in the spleen increased markedly in response to MDT-1 administration. Increased numbers of NK and NKT cells may contribute to the alleviation of carcinogenesis by MDT-1 administration. Cultured splenic lymphocytes isolated from mice fed MDT-1 produced higher levels of interferon-gamma than control mice but showed no change in interleukin-4 production. These results suggest that MDT-1 administration skews the ratio of helper T (Th) cells type 1 (Th1) to Th2 toward Th1 dominance. MDT-1 administration resulted in increased immunoglobulin A secretion into the intestine. These results suggest that probiotic B. fibrisolvens MDT-1 may contribute to the prevention or alleviation of cancers, allergic disorders, and infectious diseases.

Effect of oral administration of Butyrivibrio fibrisolvens MDT-1 on experimental enterocolitis in mice.

Butyrivibrio fibrisolvens MDT-1, a butyrate-producing strain, was evaluated for use as a probiotic to prevent enterocolitis. Oral administration of the MDT-1 strain (10(9) CFU/dose) alleviated the symptoms of colitis (including body weight loss, diarrhea, bloody stool, organic disorder, and mucosal damage) that are induced in mice drinking water that contains 3.0% dextran sulfate sodium. In addition, myeloperoxidase (MPO) activity levels in colonic tissue were reduced, suggesting that MDT-1 mitigates bowel inflammation. The addition of MDT-1 culture supernatant inhibited the growth of nine clinical isolates of Campylobacter jejuni and Campylobacter coli that could potentially cause enterocolitis. Infection of mice with C. coli 11580-3, one of the isolates inhibited by MDT-1 in vitro, resulted in diarrhea, mucosal damage, increased MPO activity levels in colonic tissue, increased numbers of C. coli in the cecum, and decreased body weight gain. However, administration of MDT-1 to mice, prior to and during C. coli infection, reduced these effects. These results suggest that Campylobacter-induced enterocolitis can be alleviated by using B. fibrisolvens as a probiotic.

Oral administration of butyrivibrio fibrisolvens, a butyrate-producing bacterium, decreases the formation of aberrant crypt foci in the colon and rectum of mice.

Butyrivibrio fibrisolvens, a butyrate-producing ruminal bacterium, was evaluated for use as a probiotic to prevent colorectal cancer. Oral administration to Jcl:ICR mice of a new strain of B. fibrisolvens (MDT-1) that produces butyrate at a high rate (10(9) cfu/dose) increased the rate of butyrate production by fecal microbes, suggesting that MDT-1 can grow in the gut. The number of colorectal aberrant crypt foci (ACF), putative preneoplastic lesions induced by 1,2-dimethylhydrazine, was reduced after MDT-1 administration (10(9) cfu/dose, 3 times/wk for 4 wk). The number of aberrant crypts (ACs), number of foci having 3 or 4 ACs per focus, and the percentage of mice having 3 or 4 ACs per focus were also reduced, suggesting that the progress of lesions was suppressed by MDT-1. Interestingly, the MDT-1 cell homogenate did not have a similar beneficial effect. MDT-1 had low beta-glucuronidase activity, and administration of MDT-1 reduced the beta-glucuronidase activity in the colorectal contents. The numbers of natural killer (NK) and NKT cells in the spleen were markedly enhanced in response to MDT-1. Decreased beta-glucuronidase activity and increased numbers of NK and NKT cells and butyrate production may explain in part why MDT-1 administration suppressed ACF formation. These results suggest that colorectal cancer may be prevented or suppressed by the utilization of MDT-1 as a probiotic. Administration of MDT-1 had no harmful effect on the health of mice at least for 3 mo.

Characterization and transcription of the genes encoding enzymes involved in butyrate production in Butyrivibrio fibrisolvens.

Genes encoding enzymes that catalyze butyryl-CoA formation from acetyl-CoA in a type II strain of Butyrivibrio fibrisolvens were analyzed. The genes encoding thiolase, beta-hydroxybutyryl-CoA dehydrogenase, butyryl-CoA dehydrogenase, and electron transfer flavoproteins were clustered, but the crotonase gene was not present in this region. The deduced amino acid sequences of these enzymes were similar to those of clostridia. The clustered genes were shown to be cotranscribed. The rate of butyrate production increased with an increase in acetate concentration in the medium up to 5 mM, suggesting that the butyryl-CoA/acetate CoA transferase reaction limits butyrate production. Transcription of the clustered genes was not affected by acetate concentration, suggesting that acetate does not affect the synthesis of enzymes involved in butyryl-CoA formation. These results confirm that acetate stimulates butyrate production by acting as a CoA acceptor in the butyryl-CoA/acetate CoA transferase reaction.