Irritable bowel syndrome (IBS) is a multifactorial functional disorder with no clearly defined etiology or pathophysiology. Modern culture-independent techniques have improved the understanding of the gut microbiota's composition and demonstrated that an altered gut microbiota profile might be found in at least some subgroups of IBS patients. Research on IBS from a microbial perspective is gaining momentum and advancing. This review will therefore highlight potential links between the gut microbiota and IBS by discussing the current knowledge of the gut microbiota; it will also illustrate bacterial-host interactions and how alterations to these interactions could exacerbate, induce or even help alleviate IBS.
Gastrointestinal Microbiome/*physiology ; Humans ; Intestines/*microbiology ; Irritable Bowel Syndrome/*microbiology/therapy

BACKGROUND: Irritable bowel syndrome (IBS) is reported associated with the alteration of gut microbial composition termed as dysbiosis. However, the pathogenic mechanism of IBS remains unclear, while the studies of Chinese individuals are scarce. This study aimed to understand the concept of dysbiosis among patients with Chinese diarrhea-predominant IBS (IBS-D), as a degree of variance between the gut microbiomes of IBS-D population and that of a healthy population. METHODS: The patients with IBS-D were recruited (assessed according to the Rome III criteria, by IBS symptom severity score) from the Outpatient Department of Gastroenterology of Peking University Third Hospital, and volunteers as healthy controls (HCs) were enrolled, during 2013. The 16S rRNA sequences were extracted from fecal samples. Ribosomal database project resources, basic local alignment search tool, and SparCC software were used to obtain the phylotype composition of samples and the internal interactions of the microbial community. Herein, the non-parametric test, Wilcoxon rank-sum test was carried out to find the statistical significance between HC and IBS-D groups. All the P values were adjusted to q values to decrease the error rate. RESULTS: The study characterized the gut microbiomes of Chinese patients with IBS-D, and demonstrated that the dysbiosis could be characterized as directed alteration of the microbiome composition leading to greater disparity between relative abundance of two phyla, Bacteroidetes (Z = 4.77, q = 1.59 × 10) and Firmicutes (Z = -3.87, q = 5.83 × 10). Moreover, it indicated that the IBS symptom features were associated with the dysbiosis of whole gut microbiome, instead of one or several certain genera even they were dominating. Two genera, Bacteroides and Lachnospiracea incertae sedis, were identified as the core genera, meanwhile, the non-core genera contribute to a larger pan-microbiome of the gut microbiome. Furthermore, the dysbiosis in patients with IBS-D was associated with a reduction of network complexity of the interacted microbial community (HC vs. IBS-D: 639 vs. 154). The disordered metabolic functions of patients with IBS-D were identified as the potential influence of gut microbiome on the host (significant difference with q < 0.01 between HC and IBS-D). CONCLUSIONS This study supported the view of the potential influence of gut microbiome on the symptom of Chinese patients with IBS-D, and further characterized dysbiosis in Chinese patients with IBS-D, thus provided more pathological evidences for IBS-D with the further understanding of dysbiosis.
Diarrhea ; microbiology ; Dysbiosis ; microbiology ; Feces ; microbiology ; Gastrointestinal Microbiome ; genetics ; Humans ; Irritable Bowel Syndrome ; microbiology ; Models, Theoretical ; RNA, Ribosomal, 16S ; genetics

OBJECTIVETo evaluate the efficacy and safety of live combined Bifidobacterium, Lactobacillus and Enterococcus capsules in treatment of irritable bowel syndrome.

METHODSEighty-five patients [male 32, female 53; age (45.31+/-11.72) years] were given live combined Bifidobacterium, Lactobacillus and Enterococcus capsules 1260 mg/d t.i.d.x4 weeks. Syndrome scales were used to evaluate the efficacy in gastrointestinal syndrome. Fecal flora was also measured before and after the treatment. Six bacteria were cultured and the colony forming units were counted in stool. SPSS was used for data analysis.

RESULTSSeventy-four patients finished the follow-up. No side-effect was found. For treatment of irritable bowel syndrome, the effective rate of live combined Bifidobacterium, Lactobacillus and Enterococcus capsules was 56.8% in the second week, 74.3% in the fourth week and 73.0% in the sixth week. Single symptom was improved, especially in abdominal pain and stool character. The probiotica containing live combined Bifidobacterium, Lactobacillus and Enterococcus could increase bifidobacterium count (P<0.01) and lactobacillus count (P<0.05); decrease bacteroides count (P<0.05) and enterococci count (P<0.01); No obvious changes were observed in clostridium difficile colonitis and enterobacteriaceae (P>0.05).

CONCLUSIONThe result of the study indicated that the administration of live combined Bifidobacterium, Lactobacillus and Enterococcus improved the symptom of irritable bowel syndrome and that there was a gradual increase of this effect. Thereafter conditions remained stable for 2 weeks. That improvement may be associated with alterations in gastrointestinal flora.

Adult ; Bifidobacterium ; Enterococcus ; Female ; Humans ; Intestines ; microbiology ; Irritable Bowel Syndrome ; drug therapy ; Lactobacillus ; Male ; Middle Aged ; Probiotics ; therapeutic use

OBJECTIVETo explore the best program for treatment of irritable bowel syndrome (IBS) of constipation type.

METHODSNinety-five cases of IBS were randomly divided into 3 groups. Group A (n = 30) were treated by acupuncture combined with microorganism pharmaceutical preparations, group B (n = 35) by oral administration of medicine for loosening the bowel to relieve constipation plus microorganism pharmaceutical preparations, and group C (n = 30) by simple acupuncture.

RESULTSThe total effective rates were 90.0%, 77.2% and 66.7%, in the group A, B and C, respectively, with a very significant differences as the group A compared with those in the groups B, C (P < 0.01), and with no significant difference as the group B compared with that of the group C (P > 0. 05). The intestinal available bacteria, bilidobacteria and lactobacillus, increased and enteric bacilli decreased in varying degrees in the 3 groups.

CONCLUSIONAcupuncture combined with microorganism pharmaceutical preparations has a better therapeutic effect on irritable bowel syndrome of constipation type.

Acupuncture Therapy ; Adult ; Combined Modality Therapy ; Constipation ; therapy ; Female ; Humans ; Intestines ; microbiology ; Irritable Bowel Syndrome ; microbiology ; therapy ; Male ; Probiotics ; therapeutic use

Adolescent ; Adult ; Aged ; Antidepressive Agents ; therapeutic use ; Body Mass Index ; Depression ; microbiology ; Diarrhea ; microbiology ; Duloxetine Hydrochloride ; therapeutic use ; Feces ; microbiology ; Humans ; Irritable Bowel Syndrome ; drug therapy ; microbiology ; Middle Aged ; Pilot Projects ; Probiotics ; therapeutic use ; RNA, Ribosomal, 16S ; genetics ; Young Adult

Previous reviews have highlighted complementary and alternative medicine therapies that are used to treat irritable bowel syndrome (IBS) based on published clinical trial data. Here the author describes and comments on a number of potentially relevant factors that have been commonly emphasized by practitioners who treat IBS and patients who have the disease. They include gluten and other food allergies, the candida syndrome and biofilm, interference fields and post-infectious IBS, as well as mind-body factors.
Food Hypersensitivity ; complications ; immunology ; Glutens ; immunology ; Humans ; Integrative Medicine ; Irritable Bowel Syndrome ; complications ; microbiology ; pathology ; therapy ; Mind-Body Therapies ; Wound Healing

BACKGROUND/AIMS: Lactulose breath test (LBT) has been used as a presumptive surrogate marker for small intestinal bacterial overgrowth (SIBO). However, recent reports suggest that abnormal LBT cannot discriminate patients with irritable bowel syndrome (IBS) from the control. Thus, the aim of this study was to evaluate the usefulness of LBT in IBS. METHODS: LBT from 76 IBS patients, 70 functional bowel disorders (FBD), and 40 controls were examined. LBT was considered positive if (1) baseline breath hydrogen (H2) >20 parts per million (ppm) or rise of breath H2 >20 ppm above the baseline in <90 mins, or (2) baseline breath methane (CH4) >10 ppm or rise of breath CH4 >10 ppm above the baseline in <90 mins. The subjects were categorized into predominant hydrogen producers (PHP), predominant methane producers (PMP), combined producer, and both negative group based on LBT. RESULTS: The rate of abnormal LBT in the IBS, FBD, and control group were 44.7%, 41.4%, and 40.0% respectively without significant differences. The rate of PHP or PMP was not significantly different among the IBS, FBD, and control group. When clinical characteristics were analyzed in IBS and FBD according to LBT types, IBS subtypes and symptoms were not significantly different. CONCLUSIONS: LBT was not useful to discriminate IBS/FBD patients from the control. The assessment of SIBO by LBT in IBS should be revalidated in the future.
Adult ; Breath Tests/*methods ; Diagnosis, Differential ; Female ; Humans ; Intestine, Small/*microbiology ; Irritable Bowel Syndrome/*diagnosis ; Lactulose/*diagnostic use ; Male ; Middle Aged ; Predictive Value of Tests

OBJECTIVE: To assess whether the same biological conclusion, diagnostic or curative effects regarding microbial composition of irritable bowel syndrome (IBS) patients could be reached through different bioinformatics pipelines, we used two common bioinformatics pipelines (Uparse V2.0 and Mothur V1.39.5)to analyze the same fecal microbial 16S rRNA high-throughput sequencing data. METHODS: The two pipelines were used to analyze the diversity and richness of fecal microbial 16S rRNA high-throughput sequencing data of 27 samples, including 9 healthy controls (HC group), 9 diarrhea IBS patients before (IBS group) and after Rifaximin treatment (IBS-treatment, IBSt group). Analyses such as microbial diversity, principal co-ordinates analysis (PCoA), nonmetric multidimensional scaling (NMDS) and linear discriminant analysis effect size (LEfSe) were used to find out the microbial differences among HC group vs. IBS group and IBS group vs. IBSt group. RESULTS: (1) Microbial composition comparison of the 27 samples in the two pipelines showed significant variations at both family and genera levels while no significant variations at phylum level; (2) There was no significant difference in the comparison of HC vs. IBS or IBS vs. IBSt (Uparse: HC vs. IBS, F=0.98, P=0.445; IBS vs. IBSt, F=0.47,P=0.926; Mothur: HC vs.IBS, F=0.82, P=0.646; IBS vs. IBSt, F=0.37, P=0.961). The Shannon index was significantly decreased in IBSt; (3) Both workshops distinguished the significantly enriched genera between HC and IBS groups. For example, Nitrosomonas and Paraprevotella increased while Pseudoalteromonadaceae and Anaerotruncus decreased in HC group through Uparse pipeline, nevertheless Roseburia 62 increased while Butyricicoccus and Moraxellaceae decreased in HC group through Mothur pipeline.Only Uparse pipeline could pick out significant genera between IBS and IBSt, such as Pseudobutyricibrio, Clostridiaceae 1 and Clostridiumsensustricto 1. CONCLUSION There were taxonomic and phylogenetic diversity differences between the two pipelines, Mothur can get more taxonomic details because the count number of each taxonomic level is higher. Both pipelines could distinguish the significantly enriched genera between HC and IBS groups, but Uparse was more capable to identity the difference between IBS and IBSt groups. To increase the reproducibility and reliability and to retain the consistency among similar studies, it is very important to consider the impact on different pipelines.
Case-Control Studies ; Computational Biology ; DNA, Bacterial/analysis* ; Diarrhea ; Feces ; Gastrointestinal Microbiome/genetics* ; Humans ; Irritable Bowel Syndrome/microbiology* ; Phylogeny ; RNA, Ribosomal, 16S ; Reproducibility of Results ; Rifamycins ; Rifaximin

OBJECTIVETo observe the changes of intestinal flora in diarrhea type irritable bowel syndrome with Pi-wei dampness-heat syndrome (IBS-PDS).

METHODSThe seven kinds of common intestinal bacteria in feces, including enteri bacillus, enterococci, saccharomycete, bifid bacteria, lactobacillus, bacteroides and peptococcus were studied in 21 patients suffered from IBS-PDS, and compared with those in 22 patients with IBS with deficiency of Pi syndrome (DPS) and 25 healthy subjects as control.

RESULTSAs compared with the healthy subjects, the levels of enteri bacillus and enterococci were significantly increased (P<0.01), the levels of bifid bacteria, Lactobacillus and Peptococcus were significantly decreased (P < 0.01), and saccharomycete and Bacteroides were insignificantly different in patients with PDS. As compared with patients with DPS, the levels of enteri bacillus, enterococci, bifid bacteria, Lactobacillus, Peptococcus and Bacteroidaceae were significantly increased except the level of saccharomycete.

CONCLUSIONThere may be alteration of intestinal flora in patients with IBS-PDS.

Adult ; Bifidobacterium ; isolation & purification ; Diagnosis, Differential ; Diarrhea ; etiology ; microbiology ; Enterobacteriaceae ; isolation & purification ; Female ; Humans ; Intestines ; microbiology ; Irritable Bowel Syndrome ; complications ; microbiology ; Lactobacillus ; isolation & purification ; Male ; Medicine, Chinese Traditional ; Middle Aged

BACKGROUND/AIMS: The aim of this study was to investigate the incidence and risk factors of irritable bowel syndrome (IBS) in community subjects with culture-proven bacterial gastroenteritis. METHODS: This was a prospective, community-based, cohort study, which followed patients with a recent history of culture-proven bacterial gastroenteritis. IBS was diagnosed with the use of the Rome II criteria at 3 and 6 months after bacterial dysentery. RESULTS: Sixty five cases were included and completed the 6 month follow-up. Thirty four cases (52.3%) were female. Salmonella was the pathogen most frequently identified and seen in 41 patients (63.1%). The cumulative incidence of IBS among patients with microbiologically proven bacterial gastroenteritis within a community was 9.2% and 12.3% at 3 and 6 months of follow-up, respectively. The duration of initial diarrhea (> or =7 days) was associated with an increased risk for the development of IBS (aOR, 14.50 [95% CI, 1.38-152.72]; p=0.022). CONCLUSIONS: Our study suggests that the incidence of IBS among patients with culture-proven bacterial gastroenteritis within a community is similar to that reported among Western populations. A large, prospective study is encouraged to confirm our results and to evaluate the influence of the microbial species on the epidemiology of IBS in Asian populations.
Adolescent ; Adult ; Aged ; Cohort Studies ; Diarrhea/complications ; Dysentery/complications ; Female ; Follow-Up Studies ; Gastroenteritis/*complications/epidemiology/microbiology ; Humans ; Incidence ; Irritable Bowel Syndrome/*diagnosis/epidemiology/etiology ; Male ; Middle Aged ; Odds Ratio ; Prospective Studies ; Risk Factors ; Salmonella/isolation & purification ; Shigella/isolation & purification ; Young Adult