Probiotics and prebiotics in chronic inflammatory bowel diseases

The prokaryotic and eukaryotic cells of the colon exist in a highly complex, but harmonious relationship. Disturbances in this remarkable symbiosis can result in the development of inflammatory bowel diseases (IBD). Although the etiology of IBD is not entirely understood, it is known that the chronic inflammation of Crohn’s disease, ulcerative colitis and chronic pouchitis are a result of an overly aggressive immune response to the commensal intestinal flora in genetically susceptible hosts. Recent studies have enhanced our ability to understand the interaction between the host and its intestinal microflora and the role the microflora plays in maintaining intestinal homeostasis. As we begin to understand the benefi ts conferred to the intestine by the microflora, the notion of modifying the composition of the bacterial load to improve human health has arisen. A signifi cant body of research now exists investigating the role of probiotics and prebiotics in ameliorating chronic intestinal inflammation. This article will begin with an overview of the role of the commensal microflora in maintaining mucosal immune homeostasis, and how a dysregulated immune response to the intestinal microflora results in IBD. This will be followed by a summary of the use of probiotics and prebiotics in experimental and human IBD.

Dietary and metabolomic determinants of relapse in ulcerative colitis patients: A pilot prospective cohort study

AIM To identify demographic, clinical, metabolomic, and lifestyle related predictors of relapse in adult ulcerative colitis(UC) patients.METHODS In this prospective pilot study, UC patients in clinical remission were recruited and followed-up at 12 mo to assess a clinical relapse, or not. At baseline information on demographic and clinical parameters was collected. Serum and urine samples were collected for analysis of metabolomic assays using a combined direct infusion/liquid chromatography tandem mass spectrometry and nuclear magnetic resolution spectroscopy. Stool samples were also collected to measure fecal calprotectin(FCP). Dietary assessment was performed using a validated self-administered food frequency questionnaire. RESULTS Twenty patients were included(mean age: 42.7 ± 14.8 years, females: 55%). Seven patients(35%) experienced a clinical relapse during the follow-up period. While 6 patients(66.7%) with normal body weight developed a clinical relapse, 1 UC patient(9.1%) who was overweight/obese relapsed during the follow-up(P = 0.02). At baseline, poultry intake was significantly higher in patients who were still in remission during follow-up(0.9 oz vs 0.2 oz, P = 0.002). Five patients(71.4%) with FCP > 150 μg/g and 2 patients(15.4%) with normal FCP(≤ 150 μg/g) at baseline relapsed during the follow-up(P = 0.02). Interestingly, baseline urinary and serum metabolomic profiling of UC patients with or without clinical relapse within 12 mo showed a significant difference. The most important metabolites that were responsible for this discrimination were trans-aconitate, cystine and acetamide in urine, and 3-hydroxybutyrate, acetoacetate and acetone in serum. CONCLUSION A combination of baseline dietary intake, fecal calprotectin, and metabolomic factors are associated with risk of UC clinical relapse within 12 mo.

Crohn's disease genotypes of patients in remission vs relapses after infliximab discontinuation

AIM： To investigate genetic differences between Crohn＇s disease （CD） patients with a sustained remission vs relapsers after discontinuing infliximab while in cortico- steroid-free remission. METHODS： Forty-eight CD patients received infliximab and were in full corticosteroid-free clinical remission but then discontinued infliximab for reasons other than a loss of response, were identified by review of an electronic database and charts. Infliximab-associated remis- sion was defined as corticosteroid-free plus normaliza- tion of clinical disease activity [CD activity index （CDAI） 〈 150] during follow-up visits based on physician global assessments. A CD relapse （loss of infliximab-induced remission） was clinically defined as a physician visit for symptoms of disease activity （CDAI 〉 220） and a thera- peutic intervention with CD medication（s）, or a hospital- ization with complications related to active CD. Genetic analyses were performed on samples from 14 patients （n = 6 who had a sustained long term remission after stopping infliximab, n -- 8 who rapidly relapsed after stopping infliximab）. Nucleotide-binding oligomerization domain 2 （NOD2）/caspase activation recruitment do- main 15 （CARD15） polymorphisms （R702W, G908R and L1007fs） and the inflammatory bowel disease 5 （IBDS） polymorphisms （IGR2060a1 and IGR3081a1） were ana- lyzed in each group. RESULTS： Five single nucleotide polymorphisms of IBD5 and NOD2/CARD15 genes were successfully analyzed for all 14 subjects. There was no signifcant increase in frequency of the NOD2/CARD15 polymor- phisms （R702W, G908R and L1007fs） and the IBD5 polymorphisms （IGR2060al and IGR3081a1） in either group of patients; those whose disease relapsed rap- idly or those who remained in sustained long term remission following the discontinuation of infliximab. Nearly a third of patients in full clinical remission who stopped infliximab for reasons other than loss of re- sponse remained in sustained clinical remission, while two-thirds relapsed rapidly. There was a marked dif- ference in the duration of clinical remission following discontinuance of infliximab between the two groups. The patients who lost remission did so after 1.0 years 4- 0.6 years, while those still in remission were at the time of this study, 8.1 years 4- 2.6 years post-discon- tinuation of infliximab, P 〈 0.001. The 8 patients who had lost remission after discontinuing infiiximab had a mean number of 5 infusions （range 3-7）, with a mean treatment time of 7.2 mo （range 1.5 mo-15 mo）. The mean duration of time from the last infusion of inflix- imab to the time of loss of remission was 382 d （range 20 d-701 d）. The 6 patients who remained in remission after discontinuing infliximab had a mean number of 6 infusions （range 3-12）, with a mean treatment dura- tion of 12 mo （range 3.6 mo-32 too） （P = 0.45 relative to those who lost remission）. CONCLUSION： There are no IBD5 or NOD2/CARD15 mutations that predict which patients might have sus- tained remission and which will relapse rapidly after stopping infliximab.