New strain of Pediococcus pentosaceus alleviates ethanol-induced liver injury by modulating the gut microbiota and short-chain fatty acid metabolism.

Intestinal dysbiosis has been shown to be associated with the pathogenesis of alcoholic liver disease (ALD), which includes changes in the microbiota composition and bacterial overgrowth, but an effective microbe-based therapy is lacking. Pediococcus pentosaceus (P. pentosaceus) CGMCC 7049 is a newly isolated strain of probiotic that has been shown to be resistant to ethanol and bile salts. However, further studies are needed to determine whether P. pentosaceus exerts a protective effect on ALD and to elucidate the potential mechanism. To evaluate the protective effect of the probiotic P. pentosaceus on ethanol-induced liver injury in mice. A new ethanol-resistant strain of P. pentosaceus CGMCC 7049 was isolated from healthy adults in our laboratory. The chronic plus binge model of experimental ALD was established to evaluate the protective effects. Twenty-eight C57BL/6 mice were randomly divided into three groups: The control group received a pair-fed control diet and oral gavage with sterile phosphate buffered saline, the EtOH group received a ten-day Lieber-DeCarli diet containing 5% ethanol and oral gavage with phosphate buffered saline, and the P. pentosaceus group received a 5% ethanol Lieber-DeCarli diet but was treated with P. pentosaceus. One dose of isocaloric maltose dextrin or ethanol was administered by oral gavage on day 11, and the mice were sacrificed nine hours later. Blood and tissue samples (liver and gut) were harvested to evaluate gut barrier function and liver injury-related parameters. Fresh cecal contents were collected, gas chromatography-mass spectrometry was used to measure short-chain fatty acid (SCFA) concentrations, and the microbiota composition was analyzed using 16S rRNA gene sequencing. The P. pentosaceus treatment improved ethanol-induced liver injury, with lower alanine aminotransferase, aspartate transaminase and triglyceride levels and decreased neutrophil infiltration. These changes were accompanied by decreased levels of endotoxin and inflammatory cytokines, including interleukin-5, tumor necrosis factor-α, granulocyte colony-stimulating factor, keratinocyte-derived protein chemokine, macrophage inflammatory protein-1α and monocyte chemoattractant protein-1. Ethanol feeding resulted in intestinal dysbiosis and gut barrier disruption, increased relative abundance of potentially pathogenic Escherichia and Staphylococcus, and the depletion of SCFA-producing bacteria, such as Prevotella, Faecalibacterium, and Clostridium. In contrast, P. pentosaceus administration increased the microbial diversity, restored the relative abundance of Lactobacillus, Pediococcus, Prevotella, Clostridium and Akkermansia and increased propionic acid and butyric acid production by modifying SCFA-producing bacteria. Furthermore, the levels of the tight junction protein ZO-1, mucin proteins (mucin [MUC]-1, MUC-2 and MUC-4) and the antimicrobial peptide Reg3β were increased after probiotic supplementation. Based on these results, the new strain of P. pentosaceus alleviated ethanol-induced liver injury by reversing gut microbiota dysbiosis, regulating intestinal SCFA metabolism, improving intestinal barrier function, and reducing circulating levels of endotoxin and proinflammatory cytokines and chemokines. Thus, this strain is a potential probiotic treatment for ALD.

Jiang XW ，Li YT ，Ye JZ ，Lv LX ，Yang LY ，Bian XY ，Wu WR ，Wu JJ ，Shi D ，Wang Q ，Fang DQ ，Wang KC ，Wang QQ ，Lu YM ，Xie JJ ，Li LJ ... -  《-》

Pediococcus pentosaceus CECT 8330 protects DSS-induced colitis and regulates the intestinal microbiota and immune responses in mice.

Compelling evidences demonstrated that gut microbiota dysbiosis plays a critical role in the pathogenesis of inflammatory bowel diseases (IBD). Therapies for targeting the microbiota may provide alternative options for the treatment of IBD, such as probiotics. Here, we aimed to investigate the protective effect of a probiotic strain, Pediococcus pentosaceus (P. pentosaceus) CECT 8330, on dextran sulfate sodium (DSS)-induced colitis in mice. C57BL/6 mice were administered phosphate-buffered saline (PBS) or P. pentosaceus CECT 8330 (5 × 108 CFU/day) once daily by gavage for 5 days prior to or 2 days after colitis induction by DSS. Weight, fecal conditions, colon length and histopathological changes were examined. ELISA and flow cytometry were applied to determine the cytokines and regulatory T cells (Treg) ratio. Western blot was used to examine the tight junction proteins (TJP) in colonic tissues. Fecal short-chain fatty acids (SCFAs) levels and microbiota composition were analyzed by targeted metabolomics and 16S rRNA gene sequencing, respectively. The Kyoto Encyclopedia of Genes and Genomes (KEGG) and Cluster of orthologous groups of proteins (COG) pathway analysis were used to predict the microbial functional profiles. P. pentosaceus CECT 8330 treatment protected DSS-induced colitis in mice as evidenced by reducing the weight loss, disease activity index (DAI) score, histological damage, and colon length shortening. P. pentosaceus CECT 8330 decreased the serum levels of proinflammatory cytokines (TNF-α, IL-1β, and IL-6), and increased level of IL-10 in DSS treated mice. P. pentosaceus CECT 8330 upregulated the expression of ZO-1, Occludin and the ratio of Treg cells in colon tissue. P. pentosaceus CECT 8330 increased the fecal SCFAs level and relative abundances of several protective bacteria genera, including norank_f_Muribaculaceae, Lactobacillus, Bifidobacterium, and Dubosiella. Furthermore, the increased abundances of bacteria genera were positively correlated with IL-10 and SCFAs levels, and negatively associated with IL-6, IL-1β, and TNF-α, respectively. The KEGG and COG pathway analysis revealed that P. pentosaceus CECT 8330 could partially recover the metabolic pathways altered by DSS. P. pentosaceus CECT 8330 administration protects the DSS-induced colitis and modulates the gut microbial composition and function, immunological profiles, and the gut barrier function. Therefore, P. pentosaceus CECT 8330 may serve as a promising probiotic to ameliorate intestinal inflammation.

Dong F ，Xiao F ，Li X ，Li Y ，Wang X ，Yu G ，Zhang T ，Wang Y ... -  《Journal of Translational Medicine》

Pediococcus pentosaceus LI05 alleviates DSS-induced colitis by modulating immunological profiles, the gut microbiota and short-chain fatty acid levels in a mouse model.

The gut microbiota is considered a key factor in pathogenesis and progression of inflammatory bowel disease (IBD). The bacterium Pediococcus pentosaceus LI05 alleviated host inflammation by maintaining the gut epithelial integrity, modulating the host immunity, gut microbiota and metabolism, but its effect on IBD remains unclear. The present study aimed to investigate the role and mechanisms of P. pentosaceus LI05. Mice were administered P. pentosaceus LI05 or phosphate-buffered saline once daily by oral gavage for 14 days, and colitis was induced by providing mice 2% DSS-containing drinking water for 7 days. P. pentosaceus LI05 ameliorated colitis in mice and reduced the body weight loss, disease activity index (DAI) scores, colon length shortening, intestinal permeability and the proinflammatory cytokine levels. Furthermore, a significantly altered gut microbiota composition with increased diversity and short-chain fatty acid (SCFA) production was observed in mice treated with P. pentosaceus LI05. Several genera, including Akkermansia and Faecalibacterium, were differentially enriched in the P. pentosaceus LI05-treated mice and were negatively correlated with colitis indices and positively correlated with gut barrier markers and SCFA levels. The P. pentosaceus LI05 treatment alleviated intestinal inflammation by maintaining the intestinal epithelial integrity and modulating the immunological profiles, gut microbiome and metabolite composition. Based on our findings, P. pentosaceus LI05 might be applied as potential preparation to ameliorate colitis.

Bian X ，Yang L ，Wu W ，Lv L ，Jiang X ，Wang Q ，Wu J ，Li Y ，Ye J ，Fang D ，Shi D ，Wang K ，Wang Q ，Lu Y ，Xie J ，Xia J ，Li L ... -  《Microbial Biotechnology》

Intestinal HIF-1α deletion exacerbates alcoholic liver disease by inducing intestinal dysbiosis and barrier dysfunction.

Alcoholic liver disease (ALD) is characterized by gut dysbiosis and increased gut permeability. Hypoxia inducible factor 1α (HIF-1α) has been implicated in transcriptional regulation of intestinal barrier integrity and inflammation. We aimed to test the hypothesis that HIF-1α plays a critical role in gut microbiota homeostasis and the maintenance of intestinal barrier integrity in a mouse model of ALD. Wild-type (WT) and intestinal epithelial-specific Hif1a knockout mice (IEhif1α-/-) were pair-fed modified Lieber-DeCarli liquid diet containing 5% (w/v) alcohol or isocaloric maltose dextrin for 24 days. Serum levels of alanine aminotransferase and endotoxin were determined. Fecal microbiota were assessed. Liver steatosis and injury, and intestinal barrier integrity were evaluated. Alcohol feeding increased serum levels of alanine aminotransferase and lipopolysaccharide, hepatic triglyceride concentration, and liver injury in the WT mice. These deleterious effects were exaggerated in IEhif1α-/- mice. Alcohol exposure resulted in greater reduction of the expression of intestinal epithelial tight junction proteins, claudin-1 and occludin, in IEhif1α-/- mice. In addition, cathelicidin-related antimicrobial peptide and intestinal trefoil factor were further decreased by alcohol in IEhif1α-/- mice. Metagenomic analysis showed increased gut dysbiosis and significantly decreased Firmicutes/Bacteroidetes ratio in IEhif1α-/- mice compared to the WT mice exposed to alcohol. An increased abundance of Akkermansia and a decreased level of Lactobacillus in IEhif1α-/- mice were also observed. Non-absorbable antibiotic treatment reversed the liver steatosis in both WT and IEhif1α-/- mice. Intestinal HIF-1α is essential for the adaptative response to alcohol-induced changes in intestinal microbiota and barrier function associated with elevated endotoxemia and hepatic steatosis and injury. Alcohol consumption alters gut microbiota and multiple intestinal barrier protecting factors that are regulated by intestinal hypoxia-inducible factor 1α (HIF-1α). Absence of intestinal HIF-1α exacerbates gut leakiness leading to an increased translocation of bacteria and bacterial products to the liver, consequently causing alcoholic liver disease. Intestinal specific upregulation of HIF-1α could be developed as a novel approach for the treatment of alcoholic liver disease.

Shao T ，Zhao C ，Li F ，Gu Z ，Liu L ，Zhang L ，Wang Y ，He L ，Liu Y ，Liu Q ，Chen Y ，Donde H ，Wang R ，Jala VR ，Barve S ，Chen SY ，Zhang X ，Chen Y ，McClain CJ ，Feng W ... -  《-》

Inulin Ameliorates Alcoholic Liver Disease via Suppressing LPS-TLR4-Mψ Axis and Modulating Gut Microbiota in Mice.

Alcoholic liver disease (ALD) represents a chronic liver disorder caused by alcohol abuse. Numerous studies have demonstrated that gut microbiota dysbiosis plays a critical role in ALD pathogenesis. Application of prebiotic, probiotic, and dietary supplementation to the modulation of gut microbiota contributes to a novel approach to the management of ALD. Inulin, a natural prebiotic found in plants, can restore gut dysbiosis in ALD. However, the exact mechanism of dietary inulin in ALD remains largely unknown. Sixty female C57BL/6J mice were randomly divided into 4 groups: pair-fed (PF) group (PF/CON); alcohol-fed (AF) group (AF/CON); PF with inulin (INU) group (PF/INU); and AF with INU group (AF/INU). All mice were fed with isocaloric modified Lieber-DeCarli liquid diets with or without alcohol. After 6 weeks of feeding, mice were euthanized and associated indications were investigated. The results showed that chronic ethanol (EtOH) intake led to the loss of body weights, abnormal levels of transaminases, and inflammatory indicators (lipopolysaccharide [LPS], interleukin [IL]-6, IL-10, tumor necrosis factor-α, IL-17A), while inulin administration ameliorated these effects. To further understand the underlying mechanism, we investigated macrophages (Mψs) and gut microbiota in diverse groups. The number of Mψs was reduced after dietary inulin treatment in chronic EtOH exposure. Hepatic Toll-like receptor 4 (TLR4+ ) Mψs in AF/INU group were lower than AF/CON group. 16S rRNA sequencing and analysis of gut microbiota indicated the reduction of Allobaculum, Lactobacillus, and Lactococcus, as well as the increase of Parasutterella in AF group compared with PF control. Increased Allobaculum, Lactobacillus, and Lactococcus but reduced Parasutterella in AF/INU group were confirmed that dietary inulin rectified gut dysbiosis to attenuate ALD. Dietary inulin ameliorates ALD via suppressing LPS-TLR4-Mψ axis and modulating gut microbiota in mice, thus potentially provides theoretical foundation for inulin intervention in the prevention and treatment of ALD.

Yang X ，He F ，Zhang Y ，Xue J ，Li K ，Zhang X ，Zhu L ，Wang Z ，Wang H ，Yang S ... -  《-》