Showing papers by "Patrizia Brigidi published in 2007"

High-dose probiotics for the treatment of active pouchitis.

Abstract: Pouchitis is the major long-term complication after ileal-pouch anal anastomosis for ulcerative colitis. Broad-spectrum antibiotics are the mainstay of treatment in this condition. Recently, we have shown the efficacy of a highly concentrated probiotic preparation (VSL#3, 900 billions/sachet lyophilized viable bacteria) in preventing relapses of chronic pouchitis and in preventing pouchitis onset. This study was designed to evaluate the efficacy of high-dose VSL#3 in the treatment of mildly active pouchitis. Twenty-three consecutive patients with mild pouchitis, defined as a score of between 7 and 12 in the Pouchitis Disease Activity Index, which includes clinical, endoscopic, and histological criteria, were treated with VSL#3, 2 sachets b.i.d. (3600 billion bacteria/day) for four weeks. Symptomatic, endoscopic, and histologic evaluations were undertaken before and after treatment according to Pouchitis Disease Activity Index. Remission was defined as a combination of a Pouchitis Disease Activity Index clinical score of ≤2, endoscopic score of ≤1, and total Pouchitis Disease Activity Index score of ≤4. Patients in remission after treatment were treated with VSL#3, 1 sachet b.i.d. (1800 billion bacteria), as maintenance treatment for six months. The quality of life was assessed with the Inflammatory Bowel Disease Questionnaire. Sixteen of 23 patients (69 percent) were in remission after treatment. The median total Pouchitis Disease Activity Index scores before and after therapy were 10 (range, 9–12) and 4 (range, 2–11), respectively (P < 0.01). The median Inflammatory Bowel Disease Questionnaire score also significantly improved from 110 (range, 90–140) to 200 (range, 95–220; P < 0.001). All 16 patients who went into remission maintained remission during maintenance treatment. Only one patient experienced a transient bloating at the beginning of treatment. High doses of the probiotic VSL#3 are effective in the treatment of mild pouchitis. Further controlled studies are warranted.

Dynamics of Vaginal Bacterial Communities in Women Developing Bacterial Vaginosis, Candidiasis, or No Infection, Analyzed by PCR-Denaturing Gradient Gel Electrophoresis and Real-Time PCR

Abstract: The microbial flora of the vagina plays a major role in preventing genital infections, including bacterial vaginosis (BV) and candidiasis (CA). An integrated approach based on PCR-denaturing gradient gel electrophoresis (PCR-DGGE) and real-time PCR was used to study the structure and dynamics of bacterial communities in vaginal fluids of healthy women and patients developing BV and CA. Universal eubacterial primers and Lactobacillus genus-specific primers, both targeted at 16S rRNA genes, were used in DGGE and real-time PCR analysis, respectively. The DGGE profiles revealed that the vaginal flora was dominated by Lactobacillus species under healthy conditions, whereas several potentially pathogenic bacteria were present in the flora of women with BV. Lactobacilli were the predominant bacterial population in the vagina for patients affected by CA, but changes in the composition of Lactobacillus species were observed. Real-time PCR analysis allowed the quantitative estimation of variations in lactobacilli associated with BV and CA diseases. A statistically significant decrease in the relative abundance of lactobacilli was found in vaginal fluids of patients with BV compared to the relative abundance of lactobacilli in the vaginal fluids of healthy women and patients with CA.

Binding of human plasminogen to Bifidobacterium.

Abstract: Bifidobacteria constitute up to 3% of the total microbiota and represent one of the most important health-promoting bacterial groups of the human intestinal microflora. The presence of Bifidobacterium in the human gastrointestinal tract has been directly related to several health-promoting activities; however, to date, no information about the specific mechanisms of interaction with the host is available. In order to provide some insight into the molecular mechanisms involved in the interaction with the host, we investigated whether Bifidobacterium was able to capture human plasminogen on the cell surface. By using flow cytometry, we demonstrated a dose-dependent human plasminogen-binding activity for four strains belonging to three bifidobacterial species: Bifidobacterium lactis, B. bifidum, and B. longum. The binding of human plasminogen to Bifidobacterium was dependent on lysine residues of surface protein receptors. By using a proteomic approach, we identified five putative plasminogen-binding proteins in the cell wall fraction of the model strain B. lactis BI07. The data suggest that plasminogen binding to B. lactis is due to the concerted action of a number of proteins located on the bacterial cell surface, some of which are highly conserved cytoplasmic proteins which have other essential cellular functions. Our findings represent a step forward in understanding the mechanisms involved in the Bifidobacterium-host interaction.

Oxalate consumption by lactobacilli : evaluation of oxalyl-CoA decarboxylase and formyl-CoA transferase activity in Lactobacillus acidophilus

Abstract: Aims: This study was undertaken to evaluate the oxalate-degrading activity in several Lactobacillus species widely used in probiotic dairy and pharmaceutical preparations. Functional characterization of oxalyl-CoA decarboxylase and formyl-CoA transferase in Lactobacillus acidophilus was performed in order to assess the possible contribution of Lactobacillus in regulating the intestinal oxalate homeostasis. Methods and Results: In order to determine the oxalate-degrading ability in 60 Lactobacillus strains belonging to 12 species, a screening was carried out by using an enzymatic assay. A high variability in the oxalate-degrading capacity was found in the different species. Strains of Lact. acidophilus and Lactobacillus gasseri showed the highest oxalate-degrading activity. Oxalyl-CoA decarboxylase and formyl-CoA transferase genes from Lact. acidophilus LA14 were cloned and sequenced. The activity of the recombinant enzymes was assessed by capillary electrophoresis. Conclusions: Strains of Lactobacillus with a high oxalate-degrading activity were identified. The function and significance of Lact. acidophilus LA14 oxalyl-CoA decarboxylase and formyl-CoA transferase in oxalate catabolism were demonstrated. These results suggest the potential use of Lactobacillus strains for the degradation of oxalate in the human gut. Significance and Impact of the Study: Identification of probiotic strains with oxalate-degrading activity can offer the opportunity to provide this capacity to individuals suffering from an increased body burden of oxalate and oxalate-associated disorders.