Ulcerative Colitis (UC) has been reported to be related to Porphyromonas gingivalis (P. gingivalis). Porphyromonas gingivalis peptidylarginine deiminase (PPAD), a virulence factor released by P. gingivalis, is known to induce inflammatory responses. To explore the pathological relationships between PPAD and UC, we used homologous recombination technology to construct a P. gingivalis strain in which the PPAD gene was deleted (Δppad) and a Δppad strain in which the PPAD gene was restored (comΔppad). C57BL/6 mice were orally gavaged with saline, P. gingivalis, Δppad, or comΔppad twice a week for the entire 40 days (days 0-40), and then, UC was induced by dextran sodium sulfate (DSS) solution for 10 days (days 31-40). P. gingivalis and comΔppad exacerbated DDS-induced colitis, which was determined by assessing the parameters of colon length, disease activity index, and histological activity index, but Δppad failed to exacerbate DDS-induced colitis. Flow cytometry and ELISA revealed that compared with Δppad, P. gingivalis, and comΔppad increased T helper 17 (Th17) cell numbers and interleukin (IL)-17 production but decreased regulatory T cells (Tregs) numbers and IL-10 production in the spleens of mice with UC. We also cocultured P. gingivalis, Δppad, or comΔppad with T lymphocytes in vitro and found that P. gingivalis and comΔppad significantly increased Th17 cell numbers and decreased Treg cell numbers. Immunofluorescence staining of colon tissue paraffin sections also confirmed these results. The results suggested that P. gingivalis exacerbated the severity of UC in part via PPAD.
Animals ; Colitis, Ulcerative/microbiology* ; Mice ; Mice, Inbred C57BL ; Porphyromonas gingivalis/pathogenicity* ; Protein-Arginine Deiminases ; Virulence Factors

OBJECTIVETo investigate the changes in fecal flora and its correlation with the occurrence and progression of inflammatory bowel disease (IBD).

METHODSWe collected fresh fecal specimens from 167 IBD patients (including 113 with ulcerative colitis and 54 with Crohn's disease) and 54 healthy volunteers. The fecal flora was analyzed by gradient dilution method and the data of inflammatory markers including WBC, PLT, CRP and ESR were collected to assess the association between the fecal flora and the inflammatory markers.

RESULTSThe species Enterrococcus (6.60∓0.23, P<0.01), Saccharomyces (2.22∓0.27, P<0.05), Bacteriodes (5.57∓0.28, P<0.001), Bifidobacterium (5.08∓0.30, P<0.01), Peptococcus (6.22∓0.25, P<0.001), Lactobacillus (6.00∓0.26, P<0.001), and Clostridium (3.57∓0.30, P<0.05) all increased significantly, while Eubacterium (1.56∓0.24, P<0.01) reduced markedly in patients with ulcerative colitis compared with those in the control subjects. Enterrococcus (6.93∓0.28, P<0.01), Saccharomyces (2.73∓0.37, P<0.01), Bacteriodes (4.32∓0.52, P<0.05), Bifidobacterium (4.88∓0.42, P<0.05), Peptococcus (6.19∓0.32, P<0.01) and Lactobacillus (4.73∓0.47, P<0.001) all increased significantly and Eubacterium (1.01∓0.29, P<0.01) and Clostridium (0.87∓0.31, P<0.01) decreased in patients with Crohn's disease. The positivity rates of bacterial culture were consistent with the results of quantitative analysis of the fecal flora. The changes in fecal flora did not show a significant correlation with these inflammatory markers.

CONCLUSIONIBD patients have fecal flora imbalance compared with the healthy controls, and this imbalance may contribute to the occurrence and progression of IBD. The decline of Eubacterium contributes to the occurrence and development of IBD.

Adult ; Bacteria ; isolation & purification ; Bacteroides ; isolation & purification ; Bifidobacterium ; isolation & purification ; Biomarkers ; analysis ; Clostridium ; isolation & purification ; Colitis, Ulcerative ; microbiology ; Crohn Disease ; microbiology ; Enterococcus ; isolation & purification ; Eubacterium ; isolation & purification ; Feces ; microbiology ; Female ; Humans ; Inflammatory Bowel Diseases ; etiology ; microbiology ; Lactobacillus ; isolation & purification ; Male ; Peptococcus ; isolation & purification ; Saccharomyces ; isolation & purification

Toll-like receptors (TLRs) family may play important roles in inflammatory bowel disease. This study examined the expression of TLR2, TLR4 and TLR9 in the colonic tissues of patients with ulcerative colitis (UC) and explored their roles in the pathogenesis of UC. Colonic biopsies were taken from the colon of 30 patients with mild or moderate UC (at active phase) and 10 healthy controls during colonoscopy. TLR2, TLR4 and TLR9 protein expression levels were immunohistochemically detected. The mRNA expression levels of TLR2, TLR4 and TLR9 were assessed by reverse transcription polymerase chain reaction (RT-PCR). The disease activity index (DAI), colonoscopic and histologic grades and fecal microbial flora were determined. Histological examination showed that the intestinal mucous membrane of UC patients underwent acute inflammation changes. Immunohistochemistry exhibited that the expression levels of TLR2, TLR4 and TLR9 in colon epithelia and inflammatory cells were higher in UC patients than in control group (P<0.01). The mRNA expression levels of TLR2, TLR4 and TLR9 were increased in UC patients but were not detected in the normal controls. Expression levels of TLR2, TLR4 and TLR9 were positively correlated, and bore close correlation with DAI, colonoscopic and histologic grades and fecal microbial flora. An important mechanism of UC might be that abnormal activation of mucosal immunity by intestinal dysbacteriosis caused dysregulation of TLRS that mediates innate immunity.
Colitis, Ulcerative ; genetics ; metabolism ; pathology ; Colon ; metabolism ; microbiology ; Colonoscopy ; Feces ; microbiology ; Female ; Gene Expression ; Humans ; Immunohistochemistry ; Intestinal Mucosa ; metabolism ; microbiology ; Male ; Reverse Transcriptase Polymerase Chain Reaction ; Severity of Illness Index ; Toll-Like Receptor 2 ; biosynthesis ; genetics ; Toll-Like Receptor 4 ; biosynthesis ; genetics ; Toll-Like Receptor 9 ; biosynthesis ; genetics

Toll-like receptors (TLRs) are key components of the innate immune system which trigger antimicrobial host defense responses. This study aimed to investigate the impact of probiotics (Lactobacillus, Bifidobacterium) on the expression of TLR4 and tumor necrosis factor-alpha (TNF-α) in the colon mucosa of rat experimental ulcerative colitis model induced by trinitrobenzene sulfonic acid (TNBS)/ethanol and immune complexes. The gross and histological changes of the colonic mucosa were observed and assessed by the means-standard deviation and independent samples t-test. The protein expression levels of TLR4 and TNF-α were detected by using immunohistochemistry and Western blotting, respectively. It was revealed that there was visible infiltration of inflammatory cells, formation of crypt abscess, and the reduction of goblet cells in the colon tissue of experimental models. As compared with the control group, the levels of TLR4 and TNF-α protein were significantly increased in the model group (P<0.01 for both). No significant difference was found in the expression of TLR4 and TNF-α between the two-week probiotics treatment group and the model group (P>0.05), whereas significant reductions were shown in rats which were treated with probiotics for four weeks as compared with the model group (P<0.01). There was no significant difference between two probiotics-treated groups. Our results implied that probiotics were likely to play a key role in protecting ulcerative colitis by reducing the inflammatory factor TNF-α expression through inhibiting the TLR4 expression in the colon tissue of experimental models.
Animals ; Bifidobacterium ; physiology ; Blotting, Western ; Colitis, Ulcerative ; chemically induced ; metabolism ; Colon ; drug effects ; metabolism ; microbiology ; Immunohistochemistry ; Intestinal Mucosa ; drug effects ; metabolism ; microbiology ; Lactobacillus ; physiology ; Male ; Probiotics ; pharmacology ; Rabbits ; Rats ; Rats, Sprague-Dawley ; Time Factors ; Toll-Like Receptor 4 ; biosynthesis ; Trinitrobenzenesulfonic Acid ; Tumor Necrosis Factor-alpha ; metabolism