The effect of a multispecies probiotic on the intestinal microbiota and bowel movements in healthy volunteers taking the antibiotic amoxycillin

BACKGROUND: One of the side effects of antimicrobial therapy is a disturbance of the intestinal microbiota potentially resulting in antibiotic-associated diarrhea (AAD). In this placebo-controlled double-blind study, the effect of a multispecies probiotic on the composition and metabolic activity of the intestinal microbiota and bowel habits was studied in healthy volunteers taking amoxycillin. METHODS: Forty-one healthy volunteers were given 500 mg amoxycillin twice daily for 7 days and were randomized to either 5 g of a multispecies probiotic, Ecologic AAD (10(9) cfu/g), or placebo, twice daily for 14 days. Feces and questionnaires were collected on day 0, 7, 14, and 63. Feces was analyzed as to the composition of the intestinal microbiota, and beta-glucosidase activity, endotoxin concentration, Clostridium difficile toxin A, short chain fatty acids (SCFAs), and pH were determined. Bowel movements were scored according to the Bristol stool form scale. RESULTS: Mean number of enterococci increased significantly from log 4.1 at day 0 to log 5.8 (day 7) and log 6.9 (day 14) cfu/g feces (P < 0.05) during probiotic intake. Although no other significant differences were observed between both intervention groups, within each group significant changes were found over time in both microbial composition and metabolic activity. Moreover, bowel movements with a frequency >or=3 per day for at least 2 days and/or a consistency >or=5 for at least 2 days were reported less frequently in the probiotic compared to the placebo group (48%vs 79%, P < 0.05). CONCLUSIONS: Apart from an increase in enterococci no significant differences in microbial composition and metabolic activity were observed in the probiotic compared with the placebo group. However, changes over time were present in both groups, which differed significantly between the probiotic and the placebo arm, suggesting that the amoxycillin effect was modulated by probiotic intake. Moreover, the intake of a multispecies probiotic significantly reduced diarrhea-like bowel movements in healthy volunteers receiving amoxycillin.     

Effect of a tricyclic antidepressant on small intestinal motility in health and diarrhea-predominant irritable bowel syndrome

Antidepressants are used in irritable bowel syndrome (IBS) and may have effects on the gut independent of improving mood. We have investigated the actions of a tricyclic antidepressant on small intestinal motor function in eight healthy volunteers and in six patients with diarrhea-predominant IBS. Fasting ambulatory motility was recorded from six small intestinal sites for 16–18 hr while on no drug (baseline) and while taking imipramine for five days. Orocecal transit time (OCTT) was measured by lactulose hydrogen breath test, during baseline and imipramine administration. Imipramine did not alter migrating motor complex periodicity, but slowed jejunal phase III propagation velocity in controls from 7.5±1.1 to 3.6±0.5 cm/min (P<0.01) and in IBS from 7.8±0.6 to 4.4±0.5 cm/min (P<0.0001). Phase III duration at each site was increased, and total recorded phase III was greater during imipramine than baseline studies. Imipramine increased the amplitude of phase III contractions. There was no effect of imipramine on non-phase-III motility index or discrete clustered contractions. Imipramine prolonged OCTT from 73±6 min to 97±8 min in controls (P<0.05) and from 61±9 min to 89±8 min in IBS (P<0.05). Although OCTT was shorter in this IBS group, no motility differences were seen between controls and IBS. This demonstration that a tricyclic antidepressant can modify small intestinal motor function in health and in IBS supports the view that these drugs may have therapeutic actions in IBS unrelated to mood improvement.This work was supported by the Priory Hospitals Group.     

I.31, a new combination of probiotics,improves irritable bowel syndrome-related quality of life

AIM: To determine the dose-related effects of a novel probiotic combination, I.31, on irritable bowel syndrome (IBS)-related quality of life (IBS-QoL).METHODS: A multicenter, randomized, double-blind, placebo-controlled intervention clinical trial with three parallel arms was designed. A total of 84 patients (53 female, 31 male; age range 20-70 years) with IBS and diarrhea according to Rome-III criteria were randomly allocated to receive one capsule a day for 6 wk containing: (1) I.31 high dose (n = 28); (2) I.31 low dose (n = 27); and (3) placebo (n = 29). At baseline, and 3 and 6 wk of treatment, patients filled the IBSQoL, Visceral Sensitivity Index (VSI), and global symptom relief questionnaires.RESULTS: During treatment, IBS-QoL increased in all groups, but this increment was significantly larger in patients treated with I.31 than in those receiving placebo (P = 0.008). After 6 wk of treatment, IBS-QoL increased by 18 ± 3 and 22 ± 4 points in the high and the low dose groups, respectively (P = 0.041 and P = 0.023 vs placebo), but only 9 ± 3 in the placebo group. Gut-specific anxiety, as measured with VSI, also showed a significantly greater improvement after 6 wk of treatment in patients treated with probiotics (by 10 ± 2 and 14 ± 2 points, high and low dose respectively, P < 0.05 for both vs 7 ± 1 score increment in placebo). Symptom relief showed no significant changes between groups. No adverse drug reactions were reported following the consumption of probiotic or placebo capsules.CONCLUSION: A new combination of three different probiotic bacteria was superior to placebo in improving IBS-related quality of life in patients with IBS and diarrhea.     

饮食对肠易激综合征影响的研究进展

肠易激综合征(irritable bowel syndrome,IBS)患者的症状常与饮食有关。目前研究认为正常人群、IBS人群及IBS各亚型在饮食上存在差异,且饮食摄入量与症状的严重程度密切相关。研究结果显示:冷食、辛辣食品、水果和蔬菜、乳制品、茶、碳酸饮料、酒精等诸多食品和饮品均可引起IBS患者的症状,本文即针对饮食与IBS的关系进行分析,以期能够为IBS患者的饮食方案提供指导。     

加强益生菌对肠易激综合征治疗的研究

在消化科门诊中,肠易激综合征（IBS）是常见疾病之一.由于病因和发病机制复杂,临床上缺乏十分有效的治疗药物.近年来随着研究的深入,不少学者开始注意到肠腔内菌群失调在IBS发病机制中的重要地位,因此,根据微生态理论采用益生菌及其产物治疗IBS具有可行性。     

Limited prolonged effects of rifaximin treatment on irritable bowel syndrome-related differences in the fecal microbiome and metabolome

Irritable bowel syndrome (IBS) is a chronic functional disorder and its development may be linked, directly and indirectly, to intestinal dysbiosis. Here we investigated the interactions between IBS symptoms and the gut microbiome, including the relation to rifaximin (1200 mg daily; 11.2 g per a treatment). We recruited 72 patients, including 31 with IBS-D (diarrhea), 11 with IBS-C (constipation), and 30 with IBS-M (mixed constipation and diarrhea) and 30 healthy controls (HCs). Of them, 68%, 64%, and 53% patients with IBS-D, IBS-C, and IBS-M, respectively, achieved 10–12 week-term improvement after the rifaximin treatment. Stool samples were collected before and after the treatment, and fecal microbiotic profiles were analyzed by deep sequencing of 16S rRNA, while stool metabolic profiles were studied by hydrogen 1-nuclear magnetic resonance (¹H-NMR) and gas chromatography–mass spectrometry (GC-MS). Of 26 identified phyla, only Bacteroidetes, Firmicutes, Proteobacteria, and Actinobacteria were consistently found in all samples. Bacteroidetes was predominant in fecal samples from HCs and IBS-D and IBS-M subjects, whereas Firmicutes was predominant in samples from IBS-C subjects. Species richness, but not community diversity, differentiated all IBS patients from HCs. Metabolic fingerprinting, using NMR spectra, distinguished HCs from all IBS patients. Thirteen metabolites identified by GC-MS differed HCs and IBS patients. However, neither metagenomics nor metabolomics analyses identified significant differences between patients with and without improvement after treatment.     

肠易激综合征和肠道感染关系研究进展

肠易激综合征(irritable bowel syndrome,IBS)以前被认为是心理学上的改变以及肠道动力的改变和感觉敏感性的增加.但是,最近一些研究提示肠道感染和IBS也有密切关系,本文就此做一综述.     

加强对感染后肠易激综合征的研究

肠易激综合征(IBS)是一组以排便后缓解或减轻的腹痛或腹部不适为主要特征的肠道综合征,根据大便习惯分为腹泻型、便秘型、混合型和不确定型。IBS是一种多因素疾病,其发病与精神心理、感染、食物等多种因素有关。人群发病率在10%~15%。感染后肠易激综合征(PI-IBS)是其中的一种亚     

Effects of probiotic fermented milk on symptoms and intestinal flora in patients with irritable bowel syndrome: A randomized,placebo-controlled trial

Abstract

Objective. The effect of probiotics on IBS symptoms has been mixed, but remains an intriguing treatment option with appeal to the patient. Material and methods. Patients fulfilling the Rome II criteria were randomized double-blind to a daily intake of 500 ml of fermented milk containing at least 5 × 10⁷ CFU/ml of Lactobacillus paracasei ssp paracasei F19, Lactobacillus acidophilus La5 and Bifidobacterium lactis Bb12 or an equal volume of acidified milk for 8 weeks. Symptoms were assessed at baseline and weekly using a disease-specific validated symptom rating scale (IBS-SSI). The predefined primary outcome measure was patient reported adequate symptom relief. Adherence to study protocol were assessed by performing stool samples at the of the treatment period. Results. Eight-one patients were screened. Sixty-four patients were randomized; 18 patients did not complete the study due to protocol violations or withdrew due to lack of effect. Fifty-two patients (13 males) completed the study as per protocol; mean age was 51.3 years (range 29–67). The proportion of patients reporting adequate symptom relief increased in both patient groups, but there was not any statistical difference between the groups. IBS-SSI scores did not differ statistically between the groups at the end of the treatment period, but improved during the study period in both groups. Conclusions. During this 8-week trial gastrointestinal symptoms improved. However, there was no difference between treatment with fermented milk containing probiotics or acidified milk. The effect of probiotics on IBS symptoms remains uncertain and further studies are warranted.     

益生菌对肠易激综合征和炎症性肠病的作用

由于胃肠道微生物参与炎症性肠病（inflammatory bowel disease,IBD）的病理过程,而且最近研究表明微生物可能在肠易激综合征（irritable bowel syndrome,IBS）中扮演重要作用.本文重点关注益生菌在这两种疾病中的作用机制和疗效.胃肠道微生物的组成受多种因素调节,包括年龄、饮食和疾病状态.益生菌可能通过影响宿主的微生物菌群和提高黏膜的免疫调节作用发挥疗效.益生菌的口服耐受性较好.许多短期研究表明益生菌在IBS中有效,尽管只是在部分的特殊菌株和某些特定症状中有效.在IBD中,许多临床试验表明大量的益生菌在结肠袋炎和溃疡性结肠炎中有效,而对克罗恩病无明显疗效.显然,益生菌在IBS和IBD的治疗中能起到巨大的作用,但是,这些只是针对特殊的菌株.将来迫切需要进行高质量的临床研究和实验观察益菌对IBD和IBS的疗效.     

不同亚型肠易激综合征患者肠道菌群改变的观察

[目的]观察不同亚型肠易激综合征(IBS)患者肠道菌群的改变,探讨IBS的发病机制。[方法]按照罗马Ⅲ标准选取腹泻型、便秘型及混合型IBS患者各20例,另选健康人20例作对照组,观察各组粪便菌群密集度、菌群多样性、细菌比例和菌群培养检测结果,并对比分析。[结果]腹泻组菌群密集度明显降低(P0.05),且菌群多样性也明显低于对照组(P0.05);与对照组比较,各亚型IBS患者革兰阳性杆菌菌群比例均明显下降(P0.05)、革兰阴性杆菌比例明显升高(P0.05),且腹泻组与便秘组、混合组之间也有显著差别(P0.05);腹泻组、混合组革兰阳性球菌、大肠杆菌比例均较对照组有显著增高(P0.05);腹泻组与便秘组比较亦有明显差别(P0.05);混合组肠球菌与对照组比较差异有统计学意义(P0.05);各亚型IBS患者双歧杆菌、乳杆菌均有减少,与对照组相比差异有统计学意义(P0.05)。[结论]腹泻型、便秘型及混合型IBS患者均存在肠道菌群失调,以腹泻型最为明显,菌群失调应该是其发病的主要因素之一。     

Abnormal intestinal permeability in subgroups of diarrhea-predominant irritable bowel syndromes

OBJECTIVES: Irritable bowel syndrome (IBS) is a heterogeneous condition and defined according to symptoms. Low-grade inflammation has been associated with IBS, particularly that following infection, but whether altered intestinal permeability profiles relate to irritable bowel subtype or onset is uncertain. Our aim was to compare small and large intestinal permeability in various subtypes of IBS to healthy controls. METHODS: Intestinal permeability was measured using 1.8 MBq of 51Cr-EDTA and collecting urine over 24 h; Study 1: patients with diarrhea-predominant postinfectious IBS (N=15), constipation-predominant IBS (N=15), and healthy controls (N=15); Study 2: two groups of diarrhea-predominant IBS (D-IBS), one with a history of onset after acute gastroenteritis (postinfectious) (N=15) and the other without such a history (nonpostinfectious) (N=15) both compared with healthy controls (N=12). RESULTS: Permeability expressed as percentage of total dose excreted in urine (median [inter-quartile range]). Study 1: Proximal small intestinal permeability was increased in postinfectious IBS (0.19 [0.12-0.23]) in contrast to constipated IBS (0.085 [0.043-0.13]) and controls (0.07 [0.035-0.19]) (p=0.02). IBS patients with eczema, asthma, or hayfever had increased proximal small intestinal permeability compared with IBS patients without atopy (p=0.02). Study 2: Small intestinal permeability was greater in nonpostinfectious diarrhea-predominant IBS (0.84 [0.69-1.49]) compared with postinfectious IBS (0.43 [0.29-0.63], p=0.028) or controls (0.27 [0.2-0.39]), p=0.001). CONCLUSIONS: Small intestinal permeability is frequently abnormal in diarrhea-predominant IBS. Those without a history of infectious onset appear to have a more severe defect.     

Pathogenic factors involved in the development of irritable bowel syndrome: focus on a microbial role

Irritable bowel syndrome (IBS) is a symptom complex characterized by recurrent abdominal pain or discomfort, and accompanied by abnormal bowel habits, in the absence of any discernible organic abnormality. Its origin remains unclear, partly because multiple pathophysiologic mechanisms are likely to be involved. A significant proportion of patients develop IBS symptoms after an episode of gastrointestinal infection. In addition to gastrointestinal pathogens, recent evidence suggests that patients with IBS have abnormal composition and higher temporal instability of their intestinal microbiota. Because the intestinal microbiota is an important determinant of normal gut function and immunity, this instability may constitute an additional mechanism that leads to symptom generation and IBS. More importantly, a role for altered microbiota composition in IBS raises the possibility of therapeutic interventions through selective antibiotic or probiotic administration. The new concept of functional bowel diseases incorporates the bidirectional communication between the gut and the central nervous system (gut-brain axis), which may explain the multiple facets of IBS by linking emotional and cognitive centers of the brain with peripheral functioning of the gastrointestinal tract and vice versa.     

Efficacy of an encapsulated probiotic Bifidobacterium infantis 35624 in women with irritable bowel syndrome

BACKGROUND: Probiotic bacteria exhibit a variety of properties, including immunomodulatory activity, which are unique to a particular strain. Thus, not all species will necessarily have the same therapeutic potential in a particular condition. We have preliminary evidence that Bifidobacterium infantis 35624 may have utility in irritable bowel syndrome (IBS). OBJECTIVES: This study was designed to confirm the efficacy of the probiotic bacteria B. infantis 35624 in a large-scale, multicenter, clinical trial of women with IBS. A second objective of the study was to determine the optimal dosage of probiotic for administration in an encapsulated formulation. METHODS: After a 2-wk baseline, 362 primary care IBS patients, with any bowel habit subtype, were randomized to either placebo or freeze-dried, encapsulated B. infantis at a dose of 1 x 10(6), 1 x 10(8), or 1 x 10(10), cfu/mL for 4 wk. IBS symptoms were monitored daily and scored on to a 6-point Likert scale with the primary outcome variable being abdominal pain or discomfort. A composite symptom score, the subject's global assessment of IBS symptom relief, and measures of quality of life (using the IBS-QOL instrument) were also recorded. RESULTS: B. infantis 35624 at a dose of 1 x 10(8) cfu was significantly superior to placebo and all other bifidobacterium doses for the primary efficacy variable of abdominal pain as well as the composite score and scores for bloating, bowel dysfunction, incomplete evacuation, straining, and the passage of gas at the end of the 4-wk study. The improvement in global symptom assessment exceeded placebo by more than 20% (p < 0.02). Two other doses of probiotic (1 x 10(6) and 1 x 10(10)) were not significantly different from placebo; of these, the 1 x 10(10) dose was associated with significant formulation problems. No significant adverse events were recorded. CONCLUSIONS: B. infantis 35624 is a probiotic that specifically relieves many of the symptoms of IBS. At a dosage level of 1 x 10(8) cfu, it can be delivered by a capsule making it stable, convenient to administer, and amenable to widespread use. The lack of benefits observed with the other dosage levels of the probiotic highlight the need for clinical data in the final dosage form and dose of probiotic before these products should be used in practice.