Claudio De Simone

VSL#3 probiotic-mixture induces remission in patients with active ulcerative colitis.

BACKGROUND AND AIMS:Intestinal bacteria have been implicated in the initiation and perpetuation of IBD; in contrast, “probiotic bacteria” have properties possibly effective in treating and preventing relapse of IBD. We evaluated the safety and efficacy of VSL#3 and the components, and the composition of the biopsy-associated microbiota in patients with active mild to moderate ulcerative colitis (UC).METHODS:Thirty-four ambulatory patients with active UC received open label VSL#3, 3,600 billion bacteria daily in two divided doses for 6 wk. The presence of biopsy-associated bacteria was detected using a nucleic acid-based method and the presence of VSL#3 species confirmed by DNA sequencing of 16S rRNA.RESULTS:Thirty-two patients completed 6 wk of VSL#3 treatment and 2 patients did not have the final endoscopic assessment. Intent to treat analysis demonstrated remission (UCDAI ≤ 2) in 53% (n = 18); response (decrease in UCDAI ≥ 3, but final score ≥3) in 24% (n = 8); no response in 9% (n = 3); worsening in 9% (n = 3); and failure to complete the final sigmoidoscopy assessment in 5% (n = 2). There were no biochemical or clinical adverse events related to VSL#3. Two of the components of VSL#3 were detected by PCR/DGGE in biopsies collected from 3 patients in remission.CONCLUSION:Treatment of patients with mild to moderate UC, not responding to conventional therapy, with VSL#3 resulted in a combined induction of remission/response rate of 77% with no adverse events. At least some of the bacterial species incorporated in the probiotic product reached the target site in amounts that could be detected.

Expression of cytokines, inducible nitric oxide synthase, and matrix metalloproteinases in pouchitis: effects of probiotic treatment

OBJECTIVE:The efficacy of probiotic organisms in the treatment of pouchitis has been reported. In the present study, we evaluated the tissue levels of pro- and anti-inflammatory cytokines, nitric oxide synthase, and matrix metalloproteinases in control and inflamed pouches before and after antibiotic and probiotic treatment of patients with acute pouchitis.METHODS:Pouch biopsy samples were obtained from seven patients with pouchitis before and after antibiotic and probiotic treatment. Tissue samples from five patients with normal pouches were used as controls. Cytokines were determined by ELISA, matrix metalloproteinase activity was evaluated by zymograms, and nitric oxide synthase activity was determined by measuring arginine to citrulline conversion.RESULTS:Tissue levels of tumor necrosis factor α increased (p 0.01) in pouchitis relative to uninflamed pouches and reduced after antibiotic and probiotic treatment. Also, interferon γ and interleukin 1α (IL-1α) augmented in pouchitis, but their increase did not reach statistical significance. The latter, however, were lower (p < 0.05) after treatment with the antibiotics and probiotics. Tissue levels of IL-4 and IL-10 were unchanged in inflamed pouches and unaffected by antibiotic treatment. However, IL-10 increased (p < 0.05) after probiotic treatment. Moreover, inflamed pouches had higher levels of inducible nitric oxide synthase and gelatinase activities, which decreased after treatment.CONCLUSIONS:The ability of antibiotic and probiotic treatments to increase tissue levels of IL-10, at a higher level than those observed in control pouches, and to decrease, to levels present in control pouches, proinflammatory cytokine, inducible nitric oxide synthase, and matrix metalloproteinase activity may suggest a mechanism of action to explain the efficacy of this therapeutic regime in pouchitis.

Acetyl-carnitine deficiency in Aids patients with neurotoxicity on treatment with antiretroviral nucleoside analogues

Objective:A severe dose-limiting axonal peripheral neuropathy may develop in subjects on treatment with the nucleoside analogues didanosine (ddI), zalcitabine (ddC), and stavudine (d4T). The impairment of mitrochondrial DNA synthesis is crucial to the pathogenesis of this disorder although other mechanisms have not been ruled out. The depletion of acetyl-carnitine, which regulates the metabolism and function of peripheral nerves, could contribute to the neurotoxicity of these compounds. Design:Non-randomized, cross-sectional study of selected patients. Methods:We measured the serum levels of acetyl- and total carnitine in 12 subjects with axonal peripheral neuropathy developed on treatment with different regimens of neurotoxic nucleoside analogues (ddI, ddC, d4T). Subjects who did not develop peripheral neuropathy while staying on treatment with ddI (n = 10) or zidovudine (n = 11) served as the control groups. HIV-negative subjects with axonal or demyelinating autoimmune neuropathies (n = 10) and healthy individuals (n = 13) were additional control groups. Results:Subjects experiencing axonal peripheral neuropathy on treatment with ddI, ddC and d4T had significantly reduced levels of acetyl-carnitine in comparison to the control groups. No difference was observed in the levels of total carnitine between study subjects and the control groups. Conclusions:Our results demonstrate that subjects who developed peripheral neuropathy while staying on treatment with ddI, ddC and d4T had acetyl-carnitine deficiency. The normal levels of total carnitine in the study group appear to indicate the specificity of the defect and rule out coexisting relevant nutritional problems. The critical role of acetyl-carnitine for the metabolism and function of the peripheral nerves supports the view that the acetyl-carnitine deficiency found in these subjects may contribute to the neurotoxicity of ddI, ddC and d4T, even though the interference with mitochondrial DNA synthesis is regarded as the main cause of their toxicity.

The influence of Lactobacillus brevis on ornithine decarboxylase activity and polyamine profiles in Helicobacter pylori-infected gastric mucosa.

Background.  Functional probiotics may prevent Helicobacter pylori infection, and some evidence suggests that they also possess antitumor properties. Lactobacillus brevis (CD2) is a functional Lactobacillus strain with peculiar biochemical features, essentially related to the activity of arginine deiminase. This enzyme catalyzes the catabolism of arginine and affects the biosynthesis of polyamines (putrescine, spermidine, and spermine). Polyamines are polycations found in high concentrations in both normal and neoplastic cells. Our aims were: 1, to assess whether oral administration of L. brevis (CD2) affects H. pylori survival in the human gastric mucosa; 2, to evaluate the effects of L. brevis (CD2) on polyamine biosynthesis in gastric biopsies from H. pylori‐positive patients.

Probiotic Bacteria Produce Conjugated Linoleic Acid Locally in the Gut That Targets Macrophage PPAR γ to Suppress Colitis

Background Inflammatory bowel disease (IBD) therapies are modestly successful and associated with significant side effects. Thus, the investigation of novel approaches to prevent colitis is important. Probiotic bacteria can produce immunoregulatory metabolites in vitro such as conjugated linoleic acid (CLA), a polyunsaturated fatty acid with potent anti-inflammatory effects. This study aimed to investigate the cellular and molecular mechanisms underlying the anti-inflammatory efficacy of probiotic bacteria using a mouse model of colitis. Methodology/Principal Findings The immune modulatory mechanisms of VSL#3 probiotic bacteria and CLA were investigated in a mouse model of DSS colitis. Colonic specimens were collected for histopathology, gene expression and flow cytometry analyses. Immune cell subsets in the mesenteric lymph nodes (MLN), spleen, blood and colonic lamina propria cells were phenotypically and functionally characterized. Fecal samples and colonic contents were collected to determine the effect of VSL#3 and CLA on gut microbial diversity and CLA production. CLA and VSL#3 treatment ameliorated colitis and decreased colonic bacterial diversity, a finding that correlated with decreased gut pathology. Colonic CLA concentrations were increased in response to probiotic bacterial treatment, but without systemic distribution in blood. VSL#3 and CLA decreased macrophage accumulation in the MLN of mice with DSS colitis. The loss of PPAR γ in myeloid cells abrogated the protective effect of probiotic bacteria and CLA in mice with DSS colitis. Conclusions/Significance Probiotic bacteria modulate gut microbial diversity and favor local production of CLA in the colon that targets myeloid cell PPAR γ to suppress colitis.

Diet, but not oral probiotics, effectively reduces urinary oxalate excretion and calcium oxalate supersaturation

We examined the effect of a controlled diet and two probiotic preparations on urinary oxalate excretion, a risk factor for calcium oxalate kidney stone formation, in patients with mild hyperoxaluria. Patients were randomized to a placebo, a probiotic, or a synbiotic preparation. This tested whether these probiotic preparations can increase oxalate metabolism in the intestine and/or decrease oxalate absorption from the gut. Patients were maintained on a controlled diet to remove the confounding variable of differing oxalate intake from food. Urinary oxalate excretion and calcium oxalate supersaturation on the controlled diet were significantly lower compared with baseline on a free-choice diet. Neither study preparation reduced urinary oxalate excretion nor calcium oxalate supersaturation. Fecal lactobacilli colony counts increased on both preparations, whereas enterococcal and yeast colony counts were increased on the synbiotic. Total urine volume and the excretion of oxalate and calcium were all strong independent determinants of urinary calcium oxalate supersaturation. Hence, dietary oxalate restriction reduced urinary oxalate excretion, but the tested probiotics did not influence urinary oxalate levels in patients on a restricted oxalate diet. However, this study suggests that dietary oxalate restriction is useful for kidney stone prevention.

High Dose L-Carnitine Improves Immunologic and Metabolic Parameters in Aids Patients

Several reports indicate that systemic carnitine deficiency could occur in acquired immunodeficiency disease syndrome (AIDS), and that primary and secondary carnitine deficiency leads to critical metabolic dysfunctions. L-carnitine supplementation to peripheral blood mononuclear cells (PBMCs) of AIDS patients resulted in significant enhancement of the phytohemagglutinin (PHA)-driven proliferative response. High dose L-carnitine administration (6 gr per day for two weeks) to AIDS patients treated with zidovudine also led to increased PBMCs proliferation and reduced blood levels of triglycerides. In addition, a reduction of beta 2-microglobulin serum levels as well as circulating tumor necrosis factor (TNF)-alpha, mostly in patients exhibiting highly elevated levels, were found at the end of the treatment period. Our data suggest that in vivo L-carnitine could prove useful in ameliorating both the immune response and lipid metabolism in patients with AIDS, irrespective of initial serum carnitines levels. The mechanism(s) accounting for the observed results are currently not clear. Further studies are needed to confirm the hypothesis that L-carnitine affects the expression of HIV-induced cytokine.

Immunoregulatory Mechanisms Underlying Prevention of Colitis-Associated Colorectal Cancer by Probiotic Bacteria

Background Inflammatory bowel disease (IBD) increases the risk of colorectal cancer. Probiotic bacteria produce immunoregulatory metabolites in vitro such as conjugated linoleic acid (CLA), a polyunsaturated fatty acid with potent anti-carcinogenic effects. This study aimed to investigate the cellular and molecular mechanisms underlying the efficacy of probiotic bacteria in mouse models of cancer. Methodology/Principal Findings The immune modulatory mechanisms of VSL#3 probiotic bacteria and CLA were investigated in mouse models of inflammation-driven colorectal cancer. Colonic specimens were collected for histopathology, gene expression and flow cytometry analyses. Immune cell subsets in the mesenteric lymph nodes (MLN), spleen and colonic lamina propria lymphocytes (LPL) were phenotypically and functionally characterized. Mice treated with CLA or VSL#3 recovered faster from the acute inflammatory phase of disease and had lower disease severity in the chronic, tumor-bearing phase of disease. Adenoma and adenocarcinoma formation was also diminished by both treatments. VSL#3 increased the mRNA expression of TNF-α, angiostatin and PPAR γ whereas CLA decreased COX-2 levels. Moreover, VSL#3-treated mice had increased IL-17 expression in MLN CD4+ T cells and accumulation of Treg LPL and memory CD4+ T cells. Conclusions/Significance Both CLA and VSL#3 suppressed colon carcinogenesis, although VSL#3 showed greater anti-carcinogenic and anti-inflammatory activities than CLA. Mechanistically, CLA modulated expression of COX-2 levels in the colonic mucosa, whereas VSL#3 targeted regulatory mucosal CD4+ T cell responses.

L-carnitine deficiency in AIDS patients.

ObjectiveTo evaluate carnitine (3-hydroxy-4-N-trimethyl-ammoniobutanoate) deficiency in AIDS patients by measuring serum total, free and short-chain carnitine concentrations. DesignWe conducted an open study. SettingAll patients were seen at the Infectious Diseases Clinic, Università ‘La Sapienza’, Rome, Italy. Patients, participantsTwenty-nine AIDS patients, aged 27–41 years, with a previous history of drug use; and 14 healthy age-and sex-matched controls were studied. InterventionsStudy subjects were administered 500–800 mg zidovudine daily for 2 to 28 months (8 × 6 months). Main outcome measuresCarnitine deficiency was suspected in study participants prior to data collection because of previously reported cardiac symptoms, muscle weakness, hypometabolism and/or cachexia. ResultsA marked decrease in total and free carnitine was observed in 21 (72%) subjects. Nine of these patients also had low levels of short-chain carnitine. ConclusionsAIDS patients may become carnitine-depleted and therefore at risk for alterations in fatty-acid oxidation and energy supply.

Apoptotic effects of selected strains of lactic acid bacteria on a human T leukemia cell line are associated with bacterial arginine deiminase and/or sphingomyelinase activities

The aim of the present work was, first, to analyze the apoptotic effect in vitro of sonicated preparations of selected strains of lactic acid bacteria on normal and tumor human lymphocytes. Incubation with bacterial samples led to a relevant time-dependent apoptotic cell death of Jurkat cells but not normal human peripheral blood lymphocytes. Lactobacillus brevis (CD2) samples were more efficient in inducing apoptosis of Jurkat cells than were samples of Streptococcus thermophilus (S244). In an attempt to characterize the mechanisms underlying these effects, we found that the apoptotic death-inducing ability of S244 preparations could be attributed to the ability of high levels of neutral sphingomyelinase activity to generate relevant amounts of ceramide, a known apoptotic death messenger, in Jurkat cells. On the other hand, our results indicate that apoptosis induced by CD2 samples could also be associated with high levels of arginine deiminase activity, which in turn was able to downregulate polyamine synthesis in Jurkat cells.