Flash on gut microbiome in gestational diabetes: a pilot study.

Pregnancy induces a deep modification of women's gut microbiota composition. These changes may influence hormonal and metabolic factors, increasing insulin resistance and leading to hyperglycaemia in susceptible women. Data on 29 women in pregnancy showed insignificant reductions in the Bacteroidetes/ Firmicutes ratio in women with (n. 14) and without (n. 15) gestational diabetes (GDM). Gut microbiota compositions at the genera and species level were further analysed in ten pregnant women with and ten without GDM (9 samples were excluded due to low DNA quality/quantity), showing differences in functionally specific patterns affecting host energy dietary polysaccharide metabolism pathways. According to our results, gut microbiome alteration may play a role in GDM pathogenesis through an increase of gut permeability and higher intestinal energetic balance.

Mucosal adhesion and anti-inflammatory effects of Lactobacillus rhamnosus GG in the human colonic mucosa: A proof-of-concept study.

AIM: To investigate the adhesion and anti-inflammatory effects of Lactobacillus rhamnosus GG (LGG) in the colonic mucosa of healthy and ulcerative colitis (UC) patients, both in vivo and ex vivo in an organ culture model. METHODS: For the ex vivo experiment, a total of 98 patients (68 UC patients and 30 normal subjects) were included. Endoscopic biopsies were collected and incubated with and without LGG or LGG-conditioned media to evaluate the mucosal adhesion and anti-inflammatory effects [reduction of tumor necrosis factor alpha (TNFα) and interleukin (IL)-17 expression] of the bacteria, and extraction of DNA and RNA for quantification by real-time (RT)-PCR occurred after the incubation. A dose-response study was performed by incubating biopsies at "regular", double and 5 times higher doses of LGG. For the in vivo experiment, a total of 42 patients (20 UC patients and 22 normal controls) were included. Biopsies were taken from the colons of normal subjects who consumed a commercial formulation of LGG for 7 d prior to the colonoscopy, and the adhesion of the bacteria to the colonic mucosa was evaluated by RT-PCR and compared with that of control biopsies from patients who did not consume the formulation. LGG adhesion and TNFα and IL-17 expression were compared between UC patients who consumed a regular or double dose of LGG supplementation prior to colonoscopy. RESULTS: In the ex vivo experiment, LGG showed consistent adhesion to the distal and proximal colon in normal subjects and UC patients, with a trend towards higher concentrations in the distal colon, and in UC patients, adhesion was similar in biopsies with active and quiescent inflammation. In addition, bioptic samples from UC patients incubated with LGG conditioned media (CM) showed reduced expression of TNFα and IL-17 compared with the corresponding expression in controls (P < 0.05). Incubation with a double dose of LGG increased mucosal adhesion and the anti-inflammatory effects (P < 0.05). In the in vivo experiment, LGG was detectable only in the colon of patients who consumed the LGG formulation, and bowel cleansing did not affect LGG adhesion. UC patients who consumed the double LGG dose had increased mucosal concentrations of the bacteria and reduced TNFα and IL-17 expression compared with patients who consumed the regular dose (48% and 40% reduction, respectively, P < 0.05). CONCLUSION: In an ex vivo organ culture model, LGG showed consistent adhesion and anti-inflammatory effects. Colonization by LGG after consumption for a week was demonstrated in vivo in the human colon. Increasing the administered dose increased the adhesion and effectiveness of the bacteria. For the first time, we demonstrated that LGG effectively adheres to the colonic mucosa and exerts anti-inflammatory effects, both ex vivo and in vivo.

Development of an Ex Vivo Organ Culture Technique to Evaluate Probiotic Utilization in IBD.

The consistent technical and conceptual progress in the study of the microbiota has led novel impulse to the research for therapeutical application of probiotic bacteria in human pathologies, such as inflammatory bowel disease (IBD). Considering the heterogenous results of probiotics in clinical studies, the model of translational medicine may lead to a more specific and efficacious utilization of probiotic bacteria in IBD. In this regard, the selection and utilization of appropriate experimental models may drive the transition from pure in vitro systems to practical clinical application. We developed a simple and reproducible ex vivo organ culture method with potential utilization for the evaluation of probiotic bacteria efficacy in IBD patients.

IL-1beta-511 and IL-1RN*2 polymorphisms in inflammatory bowel disease: An Italian population study and meta-analysis of European studies.

BACKGROUND: Several studies have tried to find possible associations between genetic polymorphisms and inflammatory bowel disease prevalence and/or phenotype. Our objectives were to test the frequency and phenotypic association of two polymorphisms of the interleukin-1 pathway, IL-1beta-511 and IL-1RN*2, in inflammatory bowel disease patients and controls from an Italian population, and to compare our data with previously published similar studies in Europe. METHODS: We screened 290 inflammatory bowel disease patients (178 ulcerative colitis and 112 Crohn's disease) and 106 controls for IL-1beta-511 and IL-1RN*2 polymorphisms by polymerase chain reaction (PCR)-based methods. The prevalence of the IL-1beta-511 and IL-1RN*2 polymorphisms in European inflammatory bowel disease patients was calculated by a meta-analysis of previously published studies using the Mantel-Haenszel method. RESULTS: No correlation between the IL-1 polymorphisms and inflammatory bowel disease prevalence was found in our study population. Crohn's disease patients with the IL-1beta-511 mutation had a higher rate of complicated disease. A trend for an association between the IL-1RN*2 mutation and a higher risk for inflammatory bowel disease has been found only in studies with Northern European populations. CONCLUSIONS: The IL-1beta-511 mutation can be associated with complex disease behaviour in Italian Crohn's disease patients. The IL-1RN*2 mutation may play a role in Northern European people with inflammatory bowel disease.