Systematic review with meta-analysis: rifaximin is effective and safe for the treatment of small intestine bacterial overgrowth

Current Treatment Options and Therapeutic Insights for Gastrointestinal Dysmotility and Functional Gastrointestinal Disorders

Functional gastrointestinal disorders (FGIDs) have been re-named as disorders of gut-brain interactions. These conditions are not only common in clinical practice, but also in the community. In reference to the Rome IV criteria, the most common FGIDs, include functional dyspepsia (FD) and irritable bowel syndrome (IBS). Additionally, there is substantial overlap of these disorders and other specific gastrointestinal motility disorders, such as gastroparesis. These disorders are heterogeneous and are intertwined with several proposed pathophysiological mechanisms, such as altered gut motility, intestinal barrier dysfunction, gut immune dysfunction, visceral hypersensitivity, altered GI secretion, presence and degree of bile acid malabsorption, microbial dysbiosis, and alterations to the gut-brain axis. The treatment options currently available include lifestyle modifications, dietary and gut microbiota manipulation interventions including fecal microbiota transplantation, prokinetics, antispasmodics, laxatives, and centrally and peripherally acting neuromodulators. However, treatment that targets the pathophysiological mechanisms underlying the symptoms are scanty. Pharmacological agents that are developed based on the cellular and molecular mechanisms underlying pathologies of these disorders might provide the best avenue for future pharmaceutical development. The currently available therapies lack long-term effectiveness and safety for their use to treat motility disorders and FGIDs. Furthermore, the fundamental challenges in treating these disorders should be defined; for instance, 1. Cause and effect cannot be disentangled between symptoms and pathophysiological mechanisms due to current therapies that entail the off-label use of medications to treat symptoms. 2. Despite the knowledge that the microbiota in our gut plays an essential part in maintaining gut health, their exact functions in gut homeostasis are still unclear. What constitutes a healthy microbiome and further, the precise definition of gut microbial dysbiosis is lacking. More comprehensive, large-scale, and longitudinal studies utilizing multi-omics data are needed to dissect the exact contribution of gut microbial alterations in disease pathogenesis. Accordingly, we review the current treatment options, clinical insight on pathophysiology, therapeutic modalities, current challenges, and therapeutic clues for the clinical care and management of functional dyspepsia, gastroparesis, irritable bowel syndrome, functional constipation, and functional diarrhea.

Asian-Pacific consensus on small intestinal bacterial overgrowth in gastrointestinal disorders: An initiative of the Indian Neurogastroenterology and Motility Association

In the clinical setting, small intestinal bacterial overgrowth (SIBO) is a frequent, but under-diagnosed entity. SIBO is linked to various gastrointestinal (GI) and non-GI disorders with potentially significant morbidity. The optimal management of SIBO is undefined while there is a lack of published consensus guidelines. Against this background, under the auspices of the Indian Neurogastroenterology and Motility Association (INMA), formerly known as the Indian Motility and Functional Diseases Association (IMFDA), experts from the Asian-Pacific region with extensive research and clinical experience in the field of gut dysbiosis including SIBO developed this evidence-based practice guideline for the management of SIBO utilizing a modified Delphi process based upon 37 consensus statements, involving an electronic voting process as well as face-to-face meetings and review of relevant supporting literature. These statements include 6 statements on definition and epidemiology; 11 on etiopathogenesis and pathophysiology; 5 on clinical manifestations, differential diagnosis, and predictors; and 15 on investigations and treatment. When the proportion of those who voted either to accept completely or with minor reservations was 80% or higher, the statement was regarded as accepted. The members of the consensus team consider that this guideline would be valuable to inform clinical practice, teaching, and research on SIBO in the Asian-Pacific region as well as in other countries.

Chronic intestinal pseudo-obstruction: a case report with review of the literature and practical guidance for the clinician

Chronic Intestinal Pseudo-obstruction (CIPO) is a rare but debilitating and severe form of gastrointestinal dysmotility. The diagnosis is often made very late in the disease course due to its rarity and complexity. Treatment is mainly supportive, as there is no definitive cure. Pharmacologic therapy comprises prokinetics, antibiotics for bacterial overgrowth and pain management. Pain can also be alleviated with intestinal decompression in selected cases. Beside the pharmacologic therapy, nutrition and fluid replacement play a key role. Rarely, intestinal transplantation is necessary in patients with CIPO and intestinal failure. In this review, we describe an advanced CIPO case and provide an update of the clinical and diagnostic features and current management strategies. The goal of our review is to raise awareness around CIPO and to give practical guidance for the clinician.

Association of small intestinal bacterial overgrowth with nonalcoholic fatty liver disease in children: A meta-analysis

It has been suggested that small intestinal bacterial overgrowth (SIBO) could cause nonalcoholic fatty liver disease (NAFLD), but this association was not examined in children by meta-analysis. This meta-analysis aimed to determine the association between SIBO and NAFLD in children. The electronic databases PubMed, Embase, and Cochrane Library were searched for studies published before April 22, 2021. The outcome was the association between SIBO and NAFLD. Three studies and 205 children were included. All three studies reported the association between SIBO and NAFLD. Children with SIBO were more likely to have NAFLD (odds ratio = 5.27, 95% confidence interval (CI): 1.66-16.68, P<0.001; I2 = 63.5%, Pheterogeneity = 0.065). When directly pooling the reported relative risks (RR) from two studies, children with NAFLD had an over 2-fold increased relative risk of developing SIBO (RR = 2.17, 05%CI: 1.66-2.82, P<0.001; I2 = 0.0%, Pheterogeneity = 0.837). This meta-analysis reports a possible association between SIBO and NAFLD in children.

Efficacy of rifaximin in treating with small intestine bacterial overgrowth: a systematic review and meta-analysis

OBJECTIVES

Over the past decades, rifaximin has been used to treat with small intestinal bacterial overgrowth (SIBO), however, the true efficacy remains unknown. This systematic review and meta-analysis was performed to assess the safety and efficacy of rifaximin in treating with patients with SIBO.

METHODS

Embase, Pubmed, Cochrane Central Register of Controlled Trials, and Web of Science were searched from inception to April, 2021 for published randomized controlled trials (RCTs) and observational studies with or without comparable arms.

RESULTS

A total of 21 observational studies and 5 RCTs involving 874 patients were included. The overall eradication rate according to intention-to-treat analysis (ITT) was 59% (95% CI: 50 to 69%; I² = 90.69%) and to per protocol analysis (PP) 63% (95% CI: 53 to 72%; I² = 90.32%). For 5 RCTs included comparing the efficacy between rifaximin and placebo or active controls, there was no significant difference (n = 203, risk ratio = 1.14, 95%CI: 0.59 to 2.19, P = 0.15, I² = 38%). Subgroup analysis and meta-regression indicated a dose-dependent eradication rate of rifaximin for SIBO.

CONCLUSION

Rifaximin is effective and safe in eradicating SIBO, with a dose-dependent efficacy and commonly associated with the improvement of the gastrointestinal symptoms and underlying diseases.

Functional gastrointestinal disorders. Overlap syndrome Clinical guidelines of the Russian Scientific Medical Society of Internal Medicine and Gastroenterological Scientific Society of Russia

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Microbiota, Bacterial Carbonic Anhydrases, and Modulators of Their Activity: Links to Human Diseases?

The involvement of the human microbiome is crucial for different host functions such as protection, metabolism, reproduction, and especially immunity. However, both endogenous and exogenous factors can affect the balance of the microbiota, creating a state of dysbiosis, which can start various gastrointestinal or systemic diseases. The challenge of future medicine is to remodel the intestinal microbiota to bring it back to healthy equilibrium (eubiosis) and, thus, counteract its negative role in the diseases' onset. The shaping of the microbiota is currently practiced in different ways ranging from diet (or use of prebiotics, probiotics, and synbiotics) to phage therapy and antibiotics, including microbiota fecal transplantation. Furthermore, because microbiota modulation is a capillary process, and because many microbiota bacteria (both beneficial and pathogenic) have carbonic anhydrases (specifically the four classes α, β, γ, and ι), we believe that the use of CA inhibitors and activators can open up new therapeutic strategies for many diseases associated with microbial dysbiosis, such as the various gastrointestinal disorders and the same colorectal cancer.

The Effect of Bacterial Infections, Probiotics and Zonulin on Intestinal Barrier Integrity

The intestinal barrier plays an extremely important role in maintaining the immune homeostasis of the gut and the entire body. It is made up of an intricate system of cells, mucus and intestinal microbiota. A complex system of proteins allows the selective permeability of elements that are safe and necessary for the proper nutrition of the body. Disturbances in the tightness of this barrier result in the penetration of toxins and other harmful antigens into the system. Such events lead to various digestive tract dysfunctions, systemic infections, food intolerances and autoimmune diseases. Pathogenic and probiotic bacteria, and the compounds they secrete, undoubtedly affect the properties of the intestinal barrier. The discovery of zonulin, a protein with tight junction regulatory activity in the epithelia, sheds new light on the understanding of the role of the gut barrier in promoting health, as well as the formation of diseases. Coincidentally, there is an increasing number of reports on treatment methods that target gut microbiota, which suggests that the prevention of gut-barrier defects may be a viable approach for improving the condition of COVID-19 patients. Various bacteria-intestinal barrier interactions are the subject of this review, aiming to show the current state of knowledge on this topic and its potential therapeutic applications.

Intestinal Decontamination Therapy for Dyskinesia and Motor Fluctuations in Parkinson's Disease

Parkinson's disease is neurodegenerative disorder with an initial robust response to levodopa. As the disease progresses, patients frequently develop dyskinesia and motor fluctuations, which are sometimes resistant to pharmacological therapy. In recent years, abnormalities in gut microbiota have been identified in these patients with a possible role in motor manifestations. Dysbiosis may reduce levodopa absorption leading to delayed “On” or “no-On” states. Among 84 consecutive patients with PD, we selected 14 with levodopa-induced dyskinesia and motor fluctuations with a Movement Disorders Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) part IV ≥ 8 points following a trial of pharmacological adjustment 2–3 months prior to study enrollment or adjustments in deep brain stimulation therapy. Patients received treatment with sodium phosphate enema followed by oral rifaximin and polyethylene glycol for 7 and 10 days, respectively. Evaluations between 14 to 21 days after starting treatment showed improvement in MDS-UPDRS-IV (P = 0.001), including duration (P = 0.001) and severity of dyskinesia (P = 0.003); duration of medication “Off”-state (P = 0.004); functional impact of motor fluctuations (P = 0.047) and complexity of motor fluctuations (P = 0.031); no statistical improvement was observed in “Off” dystonia (P = 0.109) and total motor scores (P = 0.430). Marked to moderate improvement in dyskinesia was observed in 57% of cases with blinded evaluation of videos. About 80% of patients perceived moderate to robust improvement at follow-up. A therapeutic strategy aimed at decontamination of intestines showed benefit in motor fluctuations and dyskinesia. Further studies should confirm and clarify the mechanism of improvement observed in these patients.

Review of Rifaximin: A Summary of the Current Evidence and Benefits Beyond Licensed Use

Antibiotic resistance in patients with cirrhosis continues to draw significant attention. With a propensity to frequent hospitalisations, patients with cirrhosis are subject to frequent antibiotic prescription. This increases their risk of developing resistance to one or more antimicrobial agents, making management of their condition particularly challenging. Despite advancements being made in the management of liver disease, mortality rates continue to rise: almost 5-fold in those <65 years of age while remaining the leading cause of death in those 35–49 years of age. Alternative therapeutic options to prevent disease progression and cirrhosis-associated complications are urgently required; rifaximin is one such example. The medication use in patients with cirrhosis demonstrates additional benefits beyond current licensed use in the UK, that being for the prevention of hepatic encephalopathy and traveller’s diarrhoea; rifaximin has especially been explored beyond current licensed use in the context of enteric-driven pathologies. Through the therapy’s key central action as a broad-spectrum antimicrobial, rifaximin has the ability to modulate the gut–liver axis via removal of gut microbial products associated with the progression of cirrhosis and its sequalae. The benefits of rifaximin use continues to gather momentum, given its non-absorbable nature and well-tolerated side-effect profile, and these require consideration. With broad-spectrum antimicrobial properties, its use may assist in overcoming the conundrum posed of antibiotic resistance amongst patients with cirrhosis. This literature review discusses the chemical and antimicrobial properties of rifaximin, its licenced indication for use, and its reported benefits beyond this, as well as concerns regarding rifaximin resistance.

Gut microbiota dysbiosis in functional gastrointestinal disorders: Underpinning the symptoms and pathophysiology

Functional gastrointestinal disorders (FGIDs), currently known as disorders of gut-brain interaction, are emerging microbiota-gut-brain abnormalities that are prevalent worldwide. The pathogenesis of FGIDs is heterogeneous and is intertwined with gut microbiota and its derived molecule-modulated mechanisms, including gut dysmotility, visceral hypersensitivity, gut immune abnormalities, abnormal secretion, and impaired barrier function. There has been phenomenal progress in understanding the role of gut microbiota in FGIDs by underpinning the species alternations between healthy and pathological conditions such as FGIDs. However, the precise gut microbiota-directed cellular and molecular pathogeneses of FGIDs are yet enigmatic. Determining the mechanistic link between the gut microbiota and gastrointestinal (GI) diseases has been difficult due to (i) the lack of robust animal models imitating the various aspects of human FGID pathophysiology; (ii) the absence of longitudinal human and/or animal studies to unveil the interaction of the gut microbiota with FGID-relevant pathogenesis; (iii) uncertainty about connections between human and animal studies; and (iv) insufficient data supporting a holistic view of disease-specific pathophysiological changes in FGID patients. These unidentified gaps open possibilities to explore pathological mechanisms directed through gut microbiota dysbiosis in FGIDs. The current treatment options for dysbiotic gut microbiota are limited; dietary interventions, antibiotics, probiotics, and fecal microbiota transplantation are the front-line clinical options. Here, we review the contribution of gut microbiota and its derived molecules in gut homeostasis and explore the possible pathophysiological mechanisms involved in FGIDs leading to potential therapeutics options.

Gastrointestinal manifestations of systemic sclerosis: An updated review

Systemic sclerosis is an autoimmune disease characterized by vascular disease, fibrosis of the skin, and internal organ dysfunction. Gastrointestinal involvement is the most frequent complication of internal organs, impacting up to 90% of patients. Gastrointestinal involvement can affect any region of the gastrointestinal tract from the mouth to the anus, with a predominance of disorders being observed at the level of the upper digestive tract. The gastrointestinal involvement primarily involves the esophagus, small bowel, and rectum. The severity of gastrointestinal involvement affects quality of life and is a marker of worse prognosis and mortality in these patients. In this review, we describe the current findings regarding gastrointestinal involvement by this entity.

The effectiveness of rotating versus single course antibiotics for small intestinal bacterial overgrowth

BACKGROUND

Small intestinal bacterial overgrowth treatment is usually based on antibiotics with no guidelines available.

OBJECTIVE

This study aimed to investigate the efficacy of different antibiotics to treat small intestinal bacterial overgrowth.

METHODS

Consecutive patients referred to our tertiary center and diagnosed with intestinal bacterial overgrowth were retrospectively included. Patients were diagnosed using a 75 g glucose breath test. Patients were treated either with a single antibiotic (quinolone or azole) or rotating antibiotics (quinolone and azole, one after the other) for 10 consecutive days per month for 3 months. A negative glucose breath test after antibiotic treatment was considered as remission. Quality of life (GIQLI) and gastrointestinal severity (IBS-SSS) were assessed before and after antibiotic treatment. Symptomatic evaluation was realized in simple blind of glucose breath test result: patients were unaware of their results.

RESULTS

Between August 2005 and February 2020, 223 patients were included in the analysis (female 79.8%, mean age 50.2 ± 15.7 years). Remission was observed in 119 patients (53.4%) after one course of antibiotics and was more frequent in patients receiving rotating antibiotics than in patients receiving a single antibiotic (70.0% vs. 50.8%, p = 0.050). Remission was associated with a significant improvement in quality of life (p = 0.035) and in bloating (p = 0.004).

CONCLUSION

In this study, the treatment of small intestinal bacterial overgrowth using rotating antibiotics was more effective than treatment using a single course of antibiotic. Remission was associated with improvement in both quality of life and bloating.

PK/PD Modeling to Assess Rifaximin Clinical Dosage in a Mouse Model of Staphylococcus aureus-Induced Mastitis

Staphylococcus aureus (S. aureus) is a common pathogen that causes mastitis, an infection of the milk-secreting tissue of the udder, in dairy cows, and presents a huge economic problem for the dairy industry worldwide. Thus, control and treatment of mastitis in dairy cows is vital in order to reduce the costs associated with the disease. The main purpose of the current work was to examine the current dosage of rifaximin for the treatment mastitis in cows caused by S. aureus using pharmacokinetic/pharmacodynamic integration in a mouse mastitis model. The mouse mastitis model was established via injection of S. aureus Newbould 305 (400 CFU/gland) into the mouse mammary gland. A single dose of 50, 100, 200, or 400 μg/gland, administered via intramammary infusion, was used to study the pharmacokinetics of rifaximin. The pharmacokinetic parameters were analyzed by non-compartment and non-linear mixed-effect models using Phoenix software (version 8.1; Pharsight, USA). In vivo pharmacodynamics was used to examine 18 therapeutic regimens covering various doses ranging from 25 to 800 μg/gland and three dosing intervals of 8, 12, and 24 h per 24 h experiment cycle. The antibacterial effect of rifaximin was elevated with higher concentrations of rifaximin or shorter intervals of administration. The percentage of time that drug concentrations exceeded the MIC during a dose interval (%T > MIC) was generally 100% for rifaximin and was not better than AUC₂₄/MIC in the sigmoid E_max model of inhibitory effect. The optimal antibacterial effect was 2log₁₀CFU/gland when the magnitude of AUC₂₄/MIC reached 14,281.63 h. A total of 14,281.63 h of AUC₂₄/MIC was defined as a target value in the Monte Carlo simulation. The clinically recommended dosage regimen of 100 mg/gland every 8 h in 1 day achieved an 82.97% cure rate for the treatment of bovine mastitis caused by Staphylococcus aureus infection.

Small Intestinal Bacterial Overgrowth

The term "small intestinal bacterial overgrowth" (SIBO) has been used to refer to a disorder resulting from the colonization of the small bowel by an increased number of microorganisms or by the presence of bacteria that are not usual constituents of this part of the gastrointestinal tract. Clinical presentations, often in patients with certain risk factors, can range from a full-blown malabsorption syndrome to such "functional" complaints as bloating and flatulence. SIBO is diagnosed by either culture of a small bowel aspirate or one of several breath tests. Treatment of SIBO entails risk factor modification, correction of nutritional deficiencies, and oral antibiotics.

D-lactic acidosis presenting as metabolic encephalopathy in a patient with short bowel syndrome

We present a case of D-lactic acidosis presenting as a metabolic encephalopathy secondary to small intestinal bacterial overgrowth. This patient had a known history of short bowel syndrome. Of note, this case required the alteration of treatment to promote a sustained clinical and biochemical improvement. We discuss the pathophysiological mechanisms thought to be involved. We also review the current therapies as well as potential future strategies. This case highlights the importance of the prompt clinical recognition of signs and symptoms as well as the rapid initiation of management strategies to ameliorate this condition.

What Are the Pearls and Pitfalls of the Dietary Management for Chronic Diarrhoea?

Chronic diarrhoea affects up to 14% of adults, it impacts on quality of life and its cause can be variable. Patients with chronic diarrhoea are presented with a plethora of dietary recommendations, often sought from the internet or provided by those who are untrained or inexperienced. In this review, we summarise the possible causes of chronic diarrhoea that can be managed by diet, the symptom improvement and quality of life benefits but also the potential risks of such dietary treatments. Clinicians need to consider both the benefits and risks of dietary treatments before making dietary recommendations to manage chronic diarrhoea. The pivotal role that dietitians have in ensuring optimal symptom improvement without jeopardising nutritional and overall health is discussed.

Effects of Bovine Colostrum with or without Egg on In Vitro Bacterial-Induced Intestinal Damage with Relevance for SIBO and Infectious Diarrhea

Small intestinal bacterial overgrowth (SIBO) occurs commonly, is difficult to treat, and frequently recurs. Bovine colostrum (BC) and chicken eggs contain immunoglobulins and other components that possess antimicrobial, immunoregulatory, and growth factor activities; however, it is not known if they have the ability to reduce injury caused by the presence of bacteria associated with SIBO (Streptococcus, Escherichia coli, Staphylococcus, Bacteroides, Klebsiella, Enterococcus, and Proteus) and infectious diarrhea (enteropathogenic Escherichia coli, Salmonella). We examined the effects of BC, egg, or the combination, on bacterial growth and bacteria-induced changes in transepithelial electrical resistance (TEER) and bacterial translocation across confluent Caco-2 monolayers. BC, egg, or the combination did not affect bacterial growth. Adding bacteria to monolayers reduced TEER and (with minor variations among species) increased bacterial translocation, increased monolayer apoptosis (increased caspase-3 and Baxα, reduced Bcl2), increased intercellular adhesion molecule 1 (ICAM-1), and reduced cell adhesion molecules zonulin1 (ZO1) and claudin-1. BC, egg, or the combination reduced these effects (all p < 0.01) and caused additional increases in vascular endothelial growth factor (VEGF) and Heat Shock Protein 70 (Hsp70) expression. We conclude that BC ± egg strengthens mucosal integrity against a battery of bacteria relevant for SIBO and for infectious diarrhea. Oral BC ± egg may have clinical value for these conditions, especially SIBO where eradication of precipitating organisms may be difficult to achieve.

A practical approach to the evaluation and management of gastrointestinal symptoms in patients with systemic sclerosis

The gastrointestinal (GI) tract is the most commonly affected internal organ system in systemic sclerosis (SSc). SSc may lead to impaired function in any region of the GI tract, from the esophagus to the anorectum, which causes significant morbidity as well as mortality in patient subsets. Given the low prevalence of SSc in the community, many rheumatologists may not have a systematic framework for diagnosing or treating the GI complaints in this disease. These practice recommendations aim to summarize and consolidate the current guidelines from the fields of gastroenterology and rheumatology and establish a symptom-based framework for diagnosis and management based on available evidence in the literature. Subject areas that are in need of additional research are also identified.

Differential mass spectrometry-based proteome analyses unveil major regulatory hubs in rifamycin B production in Amycolatopsis mediterranei

Rifamycin B is produced by Amycolatopsis mediterranei S699 as a secondary metabolite. Its semi-synthetic derivatives have been used for curing tuberculosis caused by Mycobacterium tuberculosis. But the emergence of rifampicin-resistant strains required analogs of rifamycin B to be developed by rifamycin biosynthetic gene cluster manipulation. In 2014 genetic engineering of the rifamycin polyketide synthase gene cluster in S699 led to a mutant, A. mediterranei DCO#34, that produced 24-desmethylrifamycin B. Unfortunately, the productivity was strongly reduced to 20 mgL^-1 as compared to 50 mgL^-1 of rifamycin B. To understand the mechanisms leading to reduced productivity and rifamycin biosynthesis by A. mediterranei S699 during the early and late growth phase we performed a proteome study for wild type strain S699, mutant DCO#34, and the non-producer strain SCO2-2. Proteins identification and relative label-free quantification were performed by nLC-MS/MS. Data are available via ProteomeXchange with identifier PXD016416. Also, in-silico protein-protein interaction approach was used to determine the relationship between different structural and regulatory proteins involved in rifamycin biosynthesis. Our studies revealed RifA, RifK, RifL, Rif-Orf19 as the major regulatory hubs. Relative abundance expression values revealed that genes encoding RifC-RifI and the transporter RifP, down-regulated in DCO#34 and genes encoding RifR, RifZ, other regulatory proteins up-regulated. SIGNIFICANCE: The study is designed mainly to understand the underlying mechanisms of rifamycin biosynthesis in Amycolatopsis mediterranei. This resulted in the identification of regulatory hubs which play a crucial role in regulating secondary metabolism. It elucidates the complex mechanism of secondary metabolite biosynthesis and their conversion and extracellular transportation in temporal correlation with the different growth phases. The study also elucidated the mechanisms leading to reduced production of analog, 24-desmethylrifamycin B by the genetically modified strain DCO#34, derivatives of which have been found effective against rifampicin-resistant strains of Mycobacterium tuberculosis. These results can be useful while carrying out genetic manipulations to improve the strains of Amycolatopsis to produce better analogs/drugs and promote the eradication of TB. Thus, this study is contributing significantly to the growing knowledge in the field of the crucial drug, rifamycin B biosynthesis by an economically important bacterium Amycolatopsis mediterranei.

Clinical efficacy of fecal microbiota transplantation for patients with small intestinal bacterial overgrowth: a randomized, placebo-controlled clinic study

Background

Small intestinal bacterial overgrowth (SIBO) is characterized by the condition that bacteria overgrowth in the small intestine. Fecal microbiota transplantation (FMT) has been applied as an effective tool for reestablishing the structure of gut microbiota. However, whether FMT could be applied as a routine SIBO treatment has not been investigated.

Methods

In this trial, 55 SIBO patients were enrolled. All participants were randomized in two groups, and were given FMT capsule or placebo capsules once a week for 4 consecutive weeks. Measurements including the lactulose hydrogen breath test gastrointestinal symptoms, as well as fecal microbiota diversity were assessed before and after FMT therapy.

Results

Gastrointestinal symptoms significantly improved in SIBO patients after treatment with FMT compared to participants in placebo group. The gut microbiota diversity of FMT group had a significant increase, while placebo group showed none.

Conclusions

This study suggests that applying FMT for patients with SIBO can alleviate gastrointestinal symptoms, indicating that FMT may be a promising and novel therapeutic regimen for SIBO.

Trial registry

This study was retrospectively registered with the Chinese Clinical Trial registry on 2019.7.10 (ID: ChiCTR1900024409, http://www.chictr.org.cn).

Long-term gastrointestinal sequelae in colon cancer survivors: prospective pilot study on identification, the need for clinical evaluation and effects of treatment

AIM

The aim of the present pilot study was to describe the type and frequency of long-term gastrointestinal symptoms within a well-defined cohort of colon cancer survivors, their wish for clinical evaluation and treatment outcomes.

METHOD

A screening survey was sent to colon cancer survivors 12, 24 and 36 months after surgery. Based on their main symptoms, patients who wished to have a consultation were referred to the gastroenterological or surgical unit of our late cancer sequelae clinic. Treatment effect was monitored by questionnaires on bowel symptoms and the EuroQol five-dimensional (EQ-5D) quality-of-life score.

RESULTS

Overall, 953 patients who had survived colon cancer received the screening survey and 767 replied (response rate 80.5%). Of these, 76 (9.9%; 95% CI 7.9%-12.2%) were referred for algorithm-based clinical evaluation and treatment of bowel dysfunction. The majority were women (69.7%) who had undergone a right-sided colonic resection (65.8%). Patients reported various symptoms, mainly including urgency, fragmented defaecation, loose stools and incontinence for liquid stools. Patients with emptying difficulties and low anterior resection syndrome-like symptoms were referred to the surgical unit and patients with diarrhoea were referred to the gastroenterological unit for clinical work-up. Our main endpoint, mean EQ-5D index after treatment, was improved compared with baseline (baseline 0.809, after treatment 0.846; p = 0.049). After treatment, self-rated bowel function and several bowel symptoms were improved as well.

CONCLUSION

This study highlights the importance of identifying colon cancer survivors in need of treatment of late gastrointestinal sequelae and clinical management in a multidisciplinary team setting.

Gut Microbial Dysbiosis in the Pathogenesis of Gastrointestinal Dysmotility and Metabolic Disorders

Of all microorganisms in the human body, the largest and most complex population resides in the gastrointestinal (GI) tract. The gut microbiota continuously adapts to the host environment and serves multiple critical functions for their hosts, including regulating host immunity, procuring energy from food, and preventing the colonization of pathogens. Mounting evidence has suggested gut microbial imbalance (dysbiosis) as a core pathophysiology in the development of GI motility and metabolic disorders, such as irritable bowel syndrome and diabetes. Current research has focused on discovering associations between these disorders and gut microbial dysbiosis; however, whether these associations are a consequence or cause is still mostly unexplored. State-of-the-art studies have investigated how gut microbes communicate with our body systems through microbiota-derived metabolites and how they are able to modulate host physiology. There is now mounting evidence that alterations in the composition of small intestinal microbes have an association with GI dysmotility and metabolic disorders. Although treatment options for gut microbial dysbiosis are currently limited, antibiotics, fecal microbiota transplantation, probiotics, and dietary interventions are currently the best options. However, treatment with broad-spectrum antibiotics has been viewed with skepticism due to the risk of developing antibiotic resistant bacteria. Studies are warranted to elucidate the cellular and molecular pathways underlying gut microbiota-host crosstalk and for the development of a powerful platform for future therapeutic approaches. Here, we review recent literature on gut microbial alterations and/or interactions involved in the pathophysiology of GI dysmotility and metabolic disorders.

COLIGENTA treatment of small intestinal bacterial overgrowth. Results of an open study

PURPOSE

The treatment of small intestinal overgrowth (SIBO) varies according to the center. The present study aimed to evaluate the efficacy of COLIGENTA, an association of colimycin and gentamycin, on SIBO symptomatology and breath test normalization PATIENTS AND METHODS: In this prospective cross-sectional open study, 150 patients with functional bowel disorders and SIBO diagnosed by lactulose hydrogen breath test (LHBT) underwent COLIGENTA oral treatment. A new HLBT was performed 4 weeks after the first HLBT.

RESULTS

The patients were mainly female (74%), with a mean age of 47.4 ± 16.2 years and a body mass index of 26.2 ± 5.9 kg/m². After treatment, a decrease of expired hydrogen concentration (P<0.001) was found in the entire population. Improvement of gastrointestinal symptoms was found in 129 patients (86%), while the breath test's normalization was found in 62 patients (42%). Logistic regression showed that normalization of bowel symptoms was not associated with demographics, clinical, or hydrogen breath concentration. In contrast, normalization of LHBT was associated with an increase of breath hydrogen concentration at time 100 min during the first test (P = 0.003; OR=1.072; 95%CI= [1.023-1.123]).

CONCLUSION

The present study shows that 10-days of COLIGENTA treatment has a high SIBO clinical improvement rate and can be used as the first or second treatment line.

Effects of Helicobacter pylori on Levodopa Pharmacokinetics

BACKGROUND

Infection with Helicobacter pylori seems overrepresented in Parkinson's disease. Clinical observations suggest a suboptimal treatment effect of levodopa in Helicobacter positive patients.

OBJECTIVE

Describe and explain the connection between a Helicobacter pylori infection of the upper gut and changes in pharmacokinetics of oral levodopa treatment in Parkinson's disease.

METHODS

PubMed, Google Scholar, and Cross Reference search was done using the key words and combined searches: Bioavailability, drug metabolism, dyskinesia, Helicobacter, L-dopa, levodopa, motor control, pharmacodynamics, pharmacokinetics, prevalence, unified Parkinson's disease rating scale.

RESULTS

The prevalence of Helicobacter pylori in Parkinson's disease patients is reported to be about 1.6-fold higher than in a control population in some studies. Helicobacter has therefore been assumed to be linked to Parkinson's disease, but the mechanism is unclear. As regards symptoms and treatment, patients with Parkinson's disease on levodopa therapy and with Helicobacter pylori infection display worse motor control than those without Helicobacter infection. Eradication of the infection improves levodopa response in Parkinson's disease, likely as a consequence of an increased oral pre-systemic bioavailability of levodopa, likely to be explained by reduced Helicobacter-dependent levodopa consumption in the stomach. In addition, small intestinal bacterial overgrowth may also have an impact on the therapeutic setting for levodopa treatment but is less well established.

CONCLUSION

Eradication of Helicobacter pylori improves levodopa bioavailability resulting in improved motor control. Eradication of Helicobacter should be considered in patients with poor symptomatic control and considerable motor fluctuations.

Management of small intestinal bacterial overgrowth by pediatric gastroenterologists in Spain

BACKGROUND

small intestinal bacterial overgrowth (SIBO) is a heterogeneous condition with nonspecific symptoms. This study aimed to report its management by pediatric gastroenterologists in Spain.

METHODS

a descriptive study was performed by means of a survey sent to 184 active members of the Spanish Society of Pediatric Gastroenterology, Hepatology and Nutrition (SEGHNP).

RESULTS

one hundred and forty-eight responses (80.4 %) were received. Forty-four patients had no predisposing condition, 31.1 % used antibiotics followed by probiotics, 33.1 % antibiotherapy concomitant with probiotics, 24.3 % only antibiotics and 10.8 % only probiotics. The diagnosis was established via clinical parameters in 73.8 % of participants and the therapeutic response was checked only by clinical data in 90 %.

CONCLUSIONS

there is high variability in the management of SIBO among pediatric population in Spain.

Chinese herbal medicine for the treatment of small intestinal bacterial overgrowth (SIBO): A protocol for systematic review and meta-analysis

BACKGROUND

Chinese medicine has a unique theory and the Chinese herbal medicine treatment is based on the integral concepts and syndrome differentiation of the Traditional Chinese Medicine system. Although antibiotics remain the mainstay of SIBO treatment, various alternative or adjunctive therapies are available, including prokinetic agents, dietary interventions, probiotics, and herbal combinations. There is accumulating evidence demonstrating the antimicrobial properties of a growing number of herbs including garlic, black cumin, cloves, cinnamon, thyme, all-spices, bay leaves, mustard, and rosemary. This has prompted an interest in herbal therapy for the treatment of SIBO. Currently, there is no systematic review focusing on efficacy of CHM in the treatment of SIBO with PCOS, so our meta-analysis aims to comprehensively explore it. Meanwhile we will provide high-quality evidence to help patients, clinicians as well as health policymakers select better treatment strategy of PCOS.

METHODS

We will search the following sources without restrictions for date, language, or publication status: PubMed, Web of Science, Cochrane Central Register of Controlled Trials (CENTRAL) Cochrane Library, EMBASE and China National Knowledge Infrastructure. We will apply a combination of Medical Subject Heading (MeSH) and free-text terms incorporating database-specific controlled vocabularies and text words to implement search strategies. We will also search the ongoing trials registered in the World Health Organization's International Clinical Trials Registry Platform. Besides, the previous relevant reviews conducted on CHM for SIBO and reference lists of included studies will also be searched.

RESULTS

This study will provide a reliable basis for the treatment of SIBO with CHM.

CONCLUSIONS

The findings will be an available reference to evaluate the efficacy and safety of CHM in the treatment of SIBO.

REGISTRATION NUMBER

INPLASY202080004.

Diarrhea-Predominant Irritable Bowel Syndrome: Medical Management Update

Irritable bowel syndrome (IBS) is a prevalent gastrointestinal disorder, which impacts the quality of life, work productivity and social activities of patients. Diarrhea-predominant IBS (IBS-D) is one of several subtypes, and accounts for approximately one third of all cases. Currently available treatments are typically unable to alleviate the cardinal symptoms of IBS-D, including abdominal pain and diarrhea, and a clinical unmet need remains for an effective treatment which simultaneously relieves multiple symptoms. Patients may benefit from a multipronged, individualized approach, including dietary modifications, and psychological and pharmacological therapies. The aim of this review is to provide an update on the available and upcoming treatment options for IBS-D in Canada, with reference to the recently updated Canadian IBS consensus guidelines. Initial treatment approaches include lifestyle modifications, dietary modifications, and non-prescription therapies such as peppermint oil. While some medications such as tricyclic antidepressants are also used to treat IBS-D symptoms, eluxadoline and rifaximin are the only two pharmacological therapies approved for the treatment of IBS-D in Canada. Key clinical trial data for the currently available pharmacological options are presented to provide an overview of the efficacy and safety of these agents.

Changes to gastrointestinal function after surgery for colorectal cancer

Bowel function is increasingly considered as an important outcome for patients undergoing surgery for colorectal cancer. Increasing technical skills and technological advances have meant fewer patients require a long-term stoma but this comes at the cost, often, of poor function. With a larger range of treatment options available for a given cancer, both function and oncology should be considered in parallel when counselling patients before surgery. In the perioperative phase, bowel function can be improved with minimally invasive surgery and enhanced recovery after surgery protocols, with limited evidence for targeted medical therapies. Early detection and sound management of surgical complications such as anastomotic leak and stricture can mitigate their adverse effects on bowel function. Long-term gastrointestinal dysfunction manifests as diarrhoea and low anterior resection syndrome for colon and rectal cancer respectively. Multi-modal strategies for low anterior resection syndrome are emerging to improve significantly quality of life after restorative rectal cancer surgery.

Effect of Combined Live Probiotics Alleviating the Gastrointestinal Symptoms of Functional Bowel Disorders

Objective

Changes of the gut microbiota are related to the pathogenesis of functional bowel disorders (FBDs), and probiotic supplementation may be an effective treatment option. Therefore, we aimed to investigate the effect of combined live probiotics on the gastrointestinal symptoms of FBDs via altering the gut microbiota.

Methods

Patients with the gastrointestinal symptoms of FBDs attending the Outpatient Department, from July to November 2019, were recruited. After the bowel preparation with polyethylene glycol electrolyte powder and colonoscopy, patients with normal result of colonoscopy were randomly divided into the probiotics group and control group. Patients in the probiotics group were prescribed with combined live Bacillus subtilis and Enterococcus faecium enteric-coated capsules for 4 weeks. Small intestinal bacteria overgrowth (SIBO) was measured by lactulose hydrogen breath test, and the microbial DNA was extracted from the fecal samples and the bacteria were classified by 16S rDNA gene amplicon sequencing.

Results

Twenty-five patients of each group were recruited, and there was no significant difference between the probiotics and control groups on baseline gastrointestinal symptom rating scale (GSRS), positive rate of SIBO, and relative abundances of the gut microbiota at the phylum level. After 4 weeks of treatment, the values of the probiotics and control groups were as follows: GSRS 1.4 ± 1.4 and 3.6 ± 1.6 and positive rate of SIBO 28.0% and 56.0%, respectively. The median relative abundances of the gut microbiota were 1.01% and 5.03% Actinobacteria and 43.80% and 35.17% Bacteroidetes at the phylum level; 0.76% and 3.29% Bifidobacterium, 0.13% and 0.89% Cillinsella, 0.03% and 0.01% Enterococcus, 0.18% and 0.36% Lachnospiraceae, 0.10% and 0.16% Ruminococcus torques group, 1.31% and 2.44% Blautia, and 0.83% and 2.02% Fusicatenibacter at the genus level (P < 0.05), respectively.

Conclusion

Combined live probiotic supplementation after the bowel preparation can alter the gut microbiota, decontaminate SIBO, and alleviate the gastrointestinal symptoms of FBDs. This trial is registered with ChiCTR1900026472.

AGA Clinical Practice Update on Small Intestinal Bacterial Overgrowth: Expert Review

DESCRIPTION

Thanks to ready access to hydrogen breath testing, small intestinal bacterial overgrowth (SIBO) is now commonly diagnosed among individuals presenting with a variety of gastrointestinal and even nongastrointestinal symptoms and is increasingly implicated in lay press and media in the causation of a diverse array of disorders. Its definition, however, remains controversial and true prevalence, accordingly, undefined. The purpose of this review, therefore, was to provide a historical background to the concept of SIBO, critically review current concepts of SIBO (including symptomatology, pathophysiology, clinical consequences, diagnosis and treatment), define unanswered questions and provide a road map toward their resolution.

METHODS

Best Practice Advice statements were developed following discussion by the 3 authors. Two authors each developed text around certain Best Practice Advice based on a review of available literature. All 3 authors reviewed the complete draft and after discussion, redrafting, and further review and revision, all of the authors agreed on a final draft. BEST PRACTICE ADVICE 1: The definition of SIBO as a clinical entity lacks precision and consistency; it is a term generally applied to a clinical disorder where symptoms, clinical signs, and/or laboratory abnormalities are attributed to changes in the numbers of bacteria or in the composition of the bacterial population in the small intestine. BEST PRACTICE ADVICE 2: Symptoms traditionally linked to SIBO include bloating, diarrhea, and abdominal pain/discomfort. Steatorrhea may be seen in more severe cases. BEST PRACTICE ADVICE 3: There is insufficient evidence to support the use of inflammatory markers, such as fecal calprotectin to detect SIBO. BEST PRACTICE ADVICE 4: Laboratory findings can include elevated folate and, less commonly, vitamin B-12 deficiency, or other nutritional deficiencies. BEST PRACTICE ADVICE 5: A major impediment to our ability to accurately define SIBO is our limited understanding of normal small intestinal microbial populations-progress in sampling technology and techniques to enumerate bacterial populations and their metabolic products should provide much needed clarity. BEST PRACTICE ADVICE 6: Controversy remains concerning the role of SIBO in the pathogenesis of common functional symptoms, such as those regarded as components of irritable bowel syndrome. BEST PRACTICE ADVICE 7: Management should focus on the identification and correction (where possible) of underlying causes, correction of nutritional deficiencies, and the administration of antibiotics. This is especially important for patients with significant maldigestion and malabsorption. BEST PRACTICE ADVICE 8: Although irritable bowel syndrome has been shown to respond to therapy with a poorly absorbed antibiotic, the role of SIBO or its eradication in the genesis of this response warrants further confirmation in randomized controlled trials. BEST PRACTICE ADVICE 9: There is a limited database to guide the clinician in developing antibiotic strategies for SIBO, in any context. Therapy remains, for the most part, empiric but must be ever mindful of the potential risks of long-term broad-spectrum antibiotic therapy.

Small Intestinal Bacterial Overgrowth: Clinical Features and Therapeutic Management

Small intestinal bacterial overgrowth (SIBO) is a common, yet underrecognized, problem. Its prevalence is unknown because SIBO requires diagnostic testing. Although abdominal bloating, gas, distension, and diarrhea are common symptoms, they do not predict positive diagnosis. Predisposing factors include proton-pump inhibitors, opioids, gastric bypass, colectomy, and dysmotility. Small bowel aspirate/culture with growth of 10-10 cfu/mL is generally accepted as the "best diagnostic method," but it is invasive. Glucose or lactulose breath testing is noninvasive but an indirect method that requires further standardization and validation for SIBO. Treatment, usually with antibiotics, aims to provide symptom relief through eradication of bacteria in the small intestine. Limited numbers of controlled studies have shown systemic antibiotics (norfloxacin and metronidazole) to be efficacious. However, 15 studies have shown rifaximin, a nonsystemic antibiotic, to be effective against SIBO and well tolerated. Through improved awareness and scientific rigor, the SIBO landscape is poised for transformation.

Faecal calprotectin levels after rifaximin treatment in patients with irritable bowel syndrome with diarrhoea: A single-center prospective study

BACKGROUND AND STUDY AIMS

Although unclear, the pathophysiology of irritable bowel syndrome (IBS) is considered to be multifactorial. Recent studies have suggested that IBS is a low-grade inflammatory bowel disease (IBD) with high faecal calprotectin (FC) levels. Rifaximin is a potential therapeutic agent for IBS with diarrhoea (IBS-D) due to its ability to decrease FC levels. This study evaluated the role of FC as a follow-up marker of IBS-D after short-course rifaximin treatment.

PATIENTS AND METHODS

Ninety-six patients with chronic diarrhoea who fulfilled the Rome IV criteria for IBS-D were enrolled in this study from outpatient clinics. After excluding 18 patients who did not complete the study due to treatment noncompliance or missing follow-up visits, 78 patients (mean age, 39.2 ± 6.9 years) with IBS-D and elevated baseline FC levels were included. An FC level of <50 μg/g was considered normal. Abdominal symptoms were assessed using a Likert scale. All patients received oral rifaximin (550 mg three times daily) for 2 weeks, followed by assessment for abdominal symptoms and FC levels; the treatment was extended to 4 weeks if FC levels remained elevated after 2 weeks of treatment.

RESULTS

FC levels normalised in 66 (84.6%) patients, including 60 and 6 patients treated for 2 and 4 weeks, respectively. The remaining 12 (15.4%) patients with persistently elevated FC levels despite 4 weeks of treatment also showed a significant decline in their final FC levels compared with the baseline, accompanied with a significant improvement in abdominal symptoms (p = 0.001). A cutoff baseline FC value of 148.5 μg/g could predict non-responders with 100% sensitivity and 50% specificity.

CONCLUSION

Short-course oral rifaximin treatment results in FC normalisation in IBS-D patients with high baseline FC values. Therefore, FC should be considered as a biomarker of follow-up after rifaximin treatment for IBS-D.

Small Intestinal Bacterial Overgrowth: How to Diagnose and Treat (and Then Treat Again)

Small intestinal bacterial overgrowth (SIBO) is a condition with presentation that can vary from asymptomatic to steatorrhea and malnutrition. Small bowel aspiration and culture is the current gold standard of diagnosis; however, this is invasive and is not without risk to the patient. Breath testing is a noninvasive and less expensive alternative method; however, it lacks diagnostic sensitivity and specificity. Novel diagnostic methods being studied include gas-sensing capsules. The mainstay of treatment is antibiotics; alternative therapies include herbal medications, dietary modifications, and prokinetic agents. Further investigation into less invasive and less harmful diagnostic methods and treatment options is warranted.

Liver Cirrhosis and Sarcopenia from the Viewpoint of Dysbiosis

Sarcopenia in patients with liver cirrhosis (LC) has been attracting much attention these days because of the close linkage to adverse outcomes. LC can be related to secondary sarcopenia due to protein metabolic disorders and energy metabolic disorders. LC is associated with profound alterations in gut microbiota and injuries at the different levels of defensive mechanisms of the intestinal barrier. Dysbiosis refers to a state in which the diversity of gut microbiota is decreased by decreasing the bacterial species and the number of bacteria that compose the gut microbiota. The severe disturbance of intestinal barrier in LC can result in dysbiosis, several bacterial infections, LC-related complications, and sarcopenia. Here in this review, we will summarize the current knowledge of the relationship between sarcopenia and dysbiosis in patients with LC.

Bariatric Surgery and Its Complications in Inflammatory Bowel Disease Patients

Recent data have suggested that bariatric procedures, especially laparoscopic sleeve gastrectomy (SG), are safe and effective weight loss measures in patients with inflammatory bowel disease (IBD). But most of the studies have looked at short-term outcomes, and there is a general lack of awareness of underlying disease processes and baseline comorbidities in IBD patients undergoing bariatric procedures. Postbariatric issues in IBD patients including diarrhea from dumping syndrome, choleretic diarrhea, a high prevalence of small intestinal bacterial overgrowth, gastroesophageal reflux disease, Barrett's esophagus, stomal ulcerations, stenosis, and renal and gallstones can complicate the natural history of IBD. This could lead to unnecessary hospitalizations, change of medical therapy, and poor surgical and quality of life outcomes. In this review, we will discuss major complications after common bariatric procedures (SG, Roux-en-Y gastric bypass, and gastric banding) and suggest possible management strategies.

Small Intestinal Bacterial Overgrowth: Comprehensive Review of Diagnosis, Prevention, and Treatment Methods

Small intestinal bacterial overgrowth (SIBO) is a commonly diagnosed gastrointestinal disorder affecting millions of individuals throughout the United States. It refers to a condition in which there is an excess and imbalance of small intestinal bacteria. Despite its prevalence, it remains underdiagnosed due to the invasive nature of diagnostic testing. Symptoms observed in SIBO, including abdominal distension, bloating, diarrhea, and gas formation, are nonspecific and can overlap with other gastrointestinal disorders. Frequently cited predisposing factors include gastric acid suppression, dysmotility, gastric bypass, and opioids. The diagnostic gold standard remains small bowel aspirate and culture. However, due to its invasive nature, it remains an unpopular method among patients and clinicians alike. Glucose and lactulose breath testing have become the go-to diagnostic method in clinical practice due to its noninvasive nature and low cost. Treatment is guided towards the eradication of bacteria in the small bowel and usually consists of a prolonged course of oral antibiotics. Due to recent advances in our understanding of the human microbiome, we are surely poised for a transformation in our approach to diagnosing and treating this condition.

Minimal Hepatic Encephalopathy: Effect of H. pylori infection and small intestinal bacterial overgrowth treatment on clinical outcomes

The effect Helicobacter pylori (Hp) infection and small intestinal bacterial over growth (SIBO) in minimal hepatic encephalopathy (MHE) is not well understood. The aim of the study was to determine the effect of eradication of Hp infection and SIBO treatment on MHE in patients with cirrhosis. Patients with cirrhosis were enrolled and MHE was determined by psychometric tests and critical flicker frequency analysis. Hp infection and SIBO were assessed by urea breath and Hydrogen breath tests respectively in patients with cirrhosis and in healthy volunteers. Patients with Hp infection and SIBO were given appropriate treatment. At six weeks follow-up, presence of Hp infection, SIBO and MHE status was reassessed. Ninety patients with cirrhosis and equal number of healthy controls were included. 55 (61.1%) patients in the cirrhotic group were diagnosed to have underlying MHE. Among cirrhotic group, Hp infection was present in 28 with MHE (50.9%) vs. in 15 without MHE (42.8%) (p = 0.45). Similarly, SIBO was present in 17 (30.9%) vs. 11 (31.4%) (p = 0.95) in patients with and without MHE respectively. In comparison with healthy controls, patients with cirrhosis were more frequently harboring Hp and SIBO (47.7% vs. 17.7% (p < 0.001) and 31.1% vs. 4.4% (p < 0.001) respectively. On follow-up, all patients showed evidence of eradication of Hp and SIBO infection. Treatment of SIBO significantly improved the state of MHE in cirrhotics, however eradication of Hp infection did not improve MHE significantly. Additionally, patients with low Model for End-Stage Liver Disease (MELD) score and belonging to Child class B had significantly better improvement in MHE. A large number of patients with cirrhosis had either active Hp infection or SIBO with or without MHE, compared to healthy controls. Treatment of SIBO significantly improved MHE in patients with cirrhosis, whereas eradication of Hp did not affect the outcome of MHE in these patients.

Short-course Rifaximin therapy efficacy and lactulose hydrogen breath test in Chinese patients with diarrhea-predominant irritable bowel syndrome

Background

Gut microbiota alterations including small intestinal bacterial overgrowth (SIBO) might play a role in pathogenesis of irritable bowel syndrome (IBS). Rifaximin could effectively and safely improve IBS symptoms. The aim of this study was to investigate the effect of rifaximin on Gastrointestinal (GI) symptoms, quality of life (QOL) and SIBO eradication in Chinese IBS-D patients.

Methods

This study included 78 IBS-D patients defined by the Rome IV criteria. Patients received 400 mg rifaximin twice daily for 2 weeks and 10-week follow-up. GI symptoms were assessed at week 0, 2, 4, 8 and 12. QOL and lactulose hydrogen breath test (LHBT) results were estimated at week 0 and 4.

Results

All participants showed significant improvements in GI symptom subdomains after rifaximin treatment (all P < 0.05), which could maintain at least 10 weeks of follow-up. Additionally, QOL scores were increased with concomitant improvement of clinical symptoms (all P < 0.05). The 45 rifaximin-responsive patients (57.7%) achieved significantly greater GI-symptom improvement than non-responders (all P < 0.05). No GI symptoms were associated with SIBO (all P > 0.05). SIBO normalization after rifaximin treatment measured by LHBT was found in 44.4% (20/45) of patients with SIBO before treatment.

Conclusion

A short course (2 weeks) of rifaximin improved GI symptoms and QOL in Chinese IBS-D patients whether they had SIBO or not. However, the efficacy of rifaximin could not be explained by the successful eradication of SIBO. Further studies on the therapeutic mechanisms of rifaximin in IBS are urgently needed.

Systemic review and network meta-analysis: Prophylactic antibiotic therapy for spontaneous bacterial peritonitis

BACKGROUND

Spontaneous bacterial peritonitis (SBP) is an important prognostic factor for outcomes in patients with cirrhosis. Antibiotic prophylaxis is recommended in patients at high risk for developing SBP, but the choice of antibiotics remains unclear.

AIM

To evaluate the efficacy of various antibiotics for prophylaxis of SBP based on randomized control trials (RCTs).

METHODS

Electronic databases were searched through November 2018 for RCTs evaluating the efficacy of therapies for primary or secondary prophylaxis of SBP. The primary outcome was the development of SBP. Sensitivity analyses limited to studies of primary or secondary prophylaxis and studies reported after 2010 were performed. The secondary outcome was the risk of all-cause mortality or transplant. The outcomes were assessed by rank of therapies based on network meta-analyses. Individual meta-analyses were also performed.

RESULTS

Thirteen RCTs (1742 patients) including norfloxacin, ciprofloxacin, rifaximin, trimethoprim-sulfamethoxazole (TMP-SMX), or placebo/no comparator were identified. Individual meta-analyses showed superiority of rifaximin over norfloxacin as well as norfloxacin and TMP-SMX over placebo. Network meta-analysis demonstrated the rank of efficacy in reducing the risk of SBP as: Rifaximin, ciprofloxacin, TMP-SMX, norfloxacin, and placebo/no comparator. Rifaximin ranked highest in sensitivity analyses limited to studies of primary or secondary prophylaxis and studies reported after 2010. Similarly, rifaximin ranked highest in reducing the risk of death/transplant.

CONCLUSION

The present comprehensive network meta-analysis provides RCT based evidence for superior efficacy of rifaximin compared to other antibiotics for the prophylaxis of SBP and reducing risk of death/transplant. Further RCTs are warranted to confirm our findings.

Systematic review: the effect of right hemicolectomy for cancer on postoperative bowel function

BACKGROUND

Right-sided cancer accounts for approximately 30% of bowel cancer in women and 22% in men. Colonic resection can cause changes in bowel function which affect daily activity. The aims are to assess the impact of right hemicolectomy for cancer on bowel function and to identify useful treatment modalities for managing bowel dysfunction after right hemicolectomy.

METHOD

The review was conducted in line with PRISMA. Eligible studies evaluated the impact of right hemicolectomy on bowel function in those treated for colorectal neoplasia or assessed the effect of surgical technique or other intervention on bowel function after right hemicolectomy. Right hemicolectomy for inflammatory bowel disease or benign cases only were excluded. Articles were limited to studies on human subjects written in English published between January 2008 and December 2018.

RESULTS

The searches identified 7531 articles. Nine articles met the inclusion criteria, of which eight were cohort studies and one was a randomised trial. Loose stool, increased bowel frequency and/or nocturnal defaecation following right-sided colectomy occurs in approximately one in five patients. Some of these symptoms may improve spontaneously with time. Bile acid malabsorption and/or small bowel bacterial overgrowth may be the cause for chronic dysfunction. Some studies report that no or little difference in outcome between right-sided and rectal resections likely suggests poor function after right-sided resection.

CONCLUSION

Right hemicolectomy can result in changes to bowel function. Patients should be counselled preoperatively, and follow-up should be designed to identify and effectively treat significantly altered bowel function.

The Influence of Small Intestinal Bacterial Overgrowth in Digestive and Extra-Intestinal Disorders

Small intestinal bacterial overgrowth (SIBO) is a condition hallmarked by an increase in the concentration of colonic-type bacteria in the small bowel. Watery diarrhea, bloating, abdominal pain and distension are the most common clinical manifestations. Additionally, malnutrition and vitamin (B12, D, A, and E) as well as minerals (iron and calcium) deficiency may be present. SIBO may mask or worsen the history of some diseases (celiac disease, irritable bowel disease), may be more common in some extra-intestinal disorders (scleroderma, obesity), or could even represent a pathogenetic link with some diseases, in which a perturbation of intestinal microbiota may be involved. On these bases, we performed a review to explore the multiple links between SIBO and digestive and extra-intestinal diseases.

Obesity and Risk of Small Intestine Bacterial Overgrowth: A Systematic Review and Meta-Analysis

BACKGROUND/OBJECTIVES

Recent studies have proposed that obesity may be associated with a higher risk of small intestine bacterial overgrowth (SIBO) although the results were inconsistent. The microbiome has a known metabolic role; its impact on obesity in animal models generated the hypothesis of an association between a dysfunctional microbiome and obesity. We performed this systematic review and meta-analysis to elucidate this possible association by summarizing all available data.

METHODS

A literature search utilizing MEDLINE and EMBASE databases from inception until August 2019 was conducted. Eligible studies included either cohort studies or cross-sectional studies that consisted of two groups of participants, those with obesity and those without obesity, and compared the prevalence of SIBO between the groups. Adjusted odds ratios (OR) from each study were consolidated by the generic inverse variance method of DerSimonian and Laird.

RESULTS

A total of five studies with 515 patients fulfilled eligibility criteria and were included in this meta-analysis. The risk of SIBO among individuals with obesity was higher than in individuals without obesity but did not reach statistical significance with a pooled OR of 2.08 [95% confidence interval (CI) 0.82-5.31; p = 0.12; I² 84%]. Sensitivity analysis including only studies from Western countries increased the pooled OR to 3.41 and reached statistical significance (95% CI 1.21-9.59; p = 0.02; I² 62%).

CONCLUSIONS

This meta-analysis found that the risk of SIBO was about two times higher among individuals with obesity compared to individuals without obesity, although the result did not reach statistical significance. The risk increased to threefold and reached statistical significance when only studies from Western countries were included. These observations may suggest the role of obesity as a predisposing factor for SIBO although more studies are still needed to corroborate these preliminary results.

Radiation enteritis: from diagnosis to management

PURPOSE OF REVIEW

As cancer treatments improve more patients than ever are living for longer with the side effects of these treatments. Radiation enteritis is a heterogenous condition with significant morbidity. The present review aims to provide a broad overview of the condition with particular attention to the diagnosis and management of the condition.

RECENT FINDINGS

Radiation enteritis appears to be more prevalent than originally thought because of patient underreporting and a lack of clinician awareness. Patient-related and treatment-related risk factors have now been identified and should be modified where possible. Medical and surgical factors have been explored, but manipulation of the gut microbiota offers one of the most exciting recent developments in disease prevention. Diagnosis and treatment are best approached in a systematic fashion with particular attention to the exclusion of recurrent malignancy and other gastrointestinal conditions. Surgery and endoscopy both offer opportunities for management of the complications of radiation enteritis. Experimental therapies offer hope for future management of radiation enteritis but large-scale human trials are needed.

SUMMARY

Radiation enteritis is an important clinical problem, but awareness is lacking amongst patients and physicians. Clinical guidelines would allow standardised management which may improve the burden of the disease for patients.

Prediction of Transcription Factors and Their Involvement in Regulating Rifamycin Production in Amycolatopsis mediterranei S699

Amycolatopsis mediterranei S699 produces rifamycin B and successors of this strain are in use for the industrial production of rifamycin B. Semisynthetic derivatives of rifamycin B are used against Mycobacterium tuberculosis that causes tuberculosis. Although the rifamycin biosynthetic gene cluster was characterized two decades ago, the regulation of rifamycin B biosynthesis in Amycolatopsis mediterranei S699 is poorly understood. In this study, we analysed the genome and proteome of Amycolatopsis mediterranei S699 and identified 1102 transcription factors which comprise about 10% of the total genome. Using interactomics approaches we delineated 30 unique transcription factors directly involved in secondary metabolism that regulate rifamycin B biosynthesis. We also predict the role of RifN as hub in controlling the regulation of other genes involved in rifamycin biosynthesis. RifN is important for maintaining the integrity of the rifamycin-network. Thus, these transcription factor can be exploited to improve rifamycin B production in Amycolatopsis mediterranei S699.

Colonic diverticular disease

Diverticula are outpouchings of the intestinal wall and are common anatomical alterations detected in the human colon. Colonic diverticulosis (the presence of diverticula in the colon; referred to as diverticulosis) remains asymptomatic in most individuals but ~25% of individuals will develop symptomatic diverticulosis, termed colonic diverticular disease (also known as diverticular disease). Diverticular disease can range in severity from symptomatic uncomplicated diverticular disease (SUDD) to symptomatic disease with complications such as acute diverticulitis or diverticular haemorrhage. Since the early 2000s, a greater understanding of the pathophysiology of diverticulosis and diverticular disease, which encompasses genetic alterations, chronic low-grade inflammation and gut dysbiosis, has led to improvements in diagnosis and management. Diagnosis of diverticular disease relies on imaging approaches, such as ultrasonography, CT and MRI, as biomarkers alone are insufficient to establish a diagnosis despite their role in determining disease severity and progression as well as in differential diagnosis. Treatments for diverticular disease include dietary fibre, pharmacological treatments such as antibiotics (rifaximin), anti-inflammatory drugs (mesalazine) and probiotics, alone or in combination, and eventually surgery. Despite being effective in treating primary disease, their effectiveness in primary and secondary prevention of complications is still uncertain.