Small intestinal bacterial overgrowth syndrome

A case of anti-VGKC antibody encephalitis and prolonged encephalopathy despite spontaneous resolution of imaging abnormalities

Anti-voltage-gated potassium channel (anti-VGKC) antibody encephalitis is a common form of autoimmune encephalitis (AE). AE is usually associated with autoimmune diseases or paraneoplastic phenomena such as seen in small cell lung cancer. Clinical presentation can include memory impairment, seizures, and psychiatric symptoms. We report a case of a 72-year-old male with non-small lung cancer in remission who presented with erosive gastritis and acute severe encephalopathy. Anti-VGKC antibody limbic encephalitis was diagnosed. Spontaneous resolution of encephalitis-associated changes on brain Magnetic Resonance (MR) with concomitant decreased circulating antibody levels were observed despite lack of overall cognitive improvement.

Abbreviations

AE: autoimmune encephalitis; AMPAR: antibody limbic encephalitis - anti-α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor encephalitis; Anti-VGKC encephalitis: anti-Voltage-gated potassium channel antibody encephalitis; CRP: c-reactive protein; CT: computed tomography; EEG: electroencephalography; ESR: erythrocyte sedimentation rate; GCS: Glasgow Coma Scale; MRImaging: Magnetic resonance imaging; NMDA-R encephalitis: Anti-N-methyl D-aspartate receptor encephalitis; PCR: polymerase chain reaction.

Alternative Treatment Approaches to Small Intestinal Bacterial Overgrowth: A Systematic Review

Background: Broad-spectrum antibiotics are the first-line treatment for small intestinal bacterial overgrowth (SIBO). However, many antibiotics have a considerable side-effect profile and SIBO commonly reoccurs after successful eradication with antibiotics. Alternative therapies such as probiotics, therapeutic diets, and herbal medicines have been used to individualize SIBO management, particularly in recalcitrant cases. Objectives: The objective of this review is to evaluate the role of alternative therapies in SIBO treatment. Data Sources: EMBASE, MEDLINE, and the Cochrane Central Register were systematically searched for clinical studies evaluating alternative therapies in the management of SIBO. Study Eligibility Criteria: Human studies in which an alternative intervention was used to treat SIBO were included. Alternative interventions were defined as an intervention that included a probiotic supplement, herbal preparation, or a dietary change. Randomized controlled trials (RCTs), nonrandomized clinical trials with or without a control, and crossover studies were included. Study Appraisal: The following information was extracted from the selected studies: study type, study participants, SIBO subtype, intervention, comparison, outcome measures, relevant results, relevant side effects, and Jadad score. Results: Eight studies met inclusion criteria. The studies evaluated probiotics (n = 5), therapeutic diet (n = 1), and herbal medicines (n = 2). Among these studies, there were four RCTs, two open-label single-arm studies, one randomized, double-blind crossover study, and one two-arm open-label study with crossover. Main results are summarized. Limitations: There may be studies not captured by the defined search criteria. Additionally, studies used different methodologies in both breath testing and measurement of clinical symptoms, making it difficult to draw conclusions on SIBO eradication and symptom improvement across studies. Conclusions and Implications: Our findings suggest preliminary evidence for a role of alternative therapies in the treatment of SIBO. However, robust clinical trials are generally lacking. Existing studies tend to be small and lack standardized formulations of treatment. Breath testing protocols and clinical symptom measurement greatly varied between studies. Large-scale, randomized, placebo-controlled trials are needed to further evaluate the best way to utilize alternative therapies in the treatment of SIBO.

Small Intestinal Bacterial Overgrowth: Clinical Presentation in Patients with Roux-en-Y Gastric Bypass

BACKGROUND

Small intestinal bacterial overgrowth (SIBO) is defined by an increased number of bacteria measured via exhaled hydrogen and/or methane gas following the ingestion of glucose. This condition is prevalent following abdominal surgery, including Roux-en-Y gastric bypass (RYGB), and associated with a variety of non-specific abdominal symptoms, often requiring an extensive diagnostic work-up.

AIM

To assess the frequency that individuals with RYGB anatomy are diagnosed with SIBO and if they are more likely to report specific gastrointestinal (GI) symptoms compared to individuals with native anatomy.

METHODS

This large matched cohort study evaluated patients with GI symptoms who underwent a glucose breath test (GBT) for SIBO evaluation, utilizing 1:2 matching between RYGB and native anatomy. Patients with positive GBT were included in univariate and multivariate analyses to distinguish the presence of ten specific GI symptoms between RYGB and native anatomy.

RESULTS

A total of 17,973 patients were included, where 271 patients with RYGB were matched to 573 patients with native anatomy that underwent GBT. Patients with RYGB anatomy and a positive GBT (199; 73.4%) as compared to those with native anatomy and a positive GBT (209; 36%) more often reported nausea, vomiting, bloating, and diarrhea. There were no differences between the two groups in the report of heartburn, regurgitation, chest pain, gas, or constipation.

CONCLUSIONS

SIBO is common in patients with RYGB and more commonly report nausea, vomiting, bloating, and diarrhea. The results of this study suggest that the report of these symptoms in RYGB should prompt early evaluation for SIBO.

Predictors of Small Intestinal Bacterial Overgrowth in Symptomatic Patients Referred for Breath Testing

Background

Indications for a breath test (BT) are well established in the symptomatic patient with risk factors predisposing them to small intestinal bacterial overgrowth (SIBO). Characteristics and the profile of this population are not well known. Our objective was to study the characteristics of patients undergoing a BT for SIBO and to identify factors associated with a positive BT.

Methods

Retrospective study was conducted from 2012 to 2016 at the neurogastroenterology unit of the Centre Hospitalier de l'Universite de Montreal (CHUM). All patients who completed a BT (lactulose and/or glucose) were included. Demographics and clinical factors were analyzed to identify predictors of positive BT. Type of antibiotic treatment and clinical response were compiled. Groups of patients with (SIBO⁺) and without SIBO (SIBO^-) were also compared.

Results

A total of 136 patients were included in the study (mean age 51.2, range 20 - 80 years; 63% women), and SIBO was detected in 33.8% (n = 46). Both groups were similar in terms of age, body mass index, and gender. SIBO was significantly associated with the presence of abdominal pain (odds ratio (OR) = 4.78; P < 0.05), bloating (OR = 5.39; P < 0.05), smoking (OR = 6.66; P < 0.05), and anemia (OR = 4.08; P < 0.05). No association was identified with gender, age, obesity, and risk factors for SIBO. Antibiotics were used in 43% of patients with a positive BT, but clinical response was not significantly different in the subgroup that received antibiotics versus the subgroup that did not.

Conclusions

The prevalence of SIBO is high in symptomatic patients who underwent breath testing. Abdominal pain, bloating, smoking, and anemia are strongly associated with SIBO. Treatment of SIBO with antibiotics needs to be further investigated to better determine its efficacy on gastrointestinal symptoms.

PREVALENCE AND FACTORS ASSOCIATED WITH SMALL INTESTINAL BACTERIAL OVERGROWTH IN PATIENTS WITH CROHN'S DISEASE: A RETROSPECTIVE STUDY AT A REFERRAL CENTER

BACKGROUND

Small intestinal bacterial overgrowth (SIBO) appears to be common in patients with Crohn's disease (CD). The rate of SIBO has been estimated at 25%-88% in this setting. However, different demographic, socioeconomic, and disease-related factors may exist between South American and North American or European populations that may limit the generalization of these findings, as the data are mainly derived from North American or European studies.

OBJECTIVE

We studied the prevalence and predictors of SIBO in CD outpatients.

METHODS

In this retrospective study, between June 2011 and June 2016, the medical records of 110 CD patients were assessed for presence of SIBO using the H2/CH4 glucose breath test. Univariate analysis was performed to investigate the potential association between SIBO and demographic, disease-related data, systemic markers of inflammation (C-reactive protein and erythrocyte sedimentation rate).

RESULTS

The SIBO rate was high in CD patients (30%). Patients with and without SIBO were comparable according to demographics, systemic inflammatory biomarkers, and disease characteristics, except to the stricturing phenotype more common in the SIBO-positive CD patients (48.5% vs 19.5%, P=0.001).

CONCLUSION

In Brazilian CD patients, SIBO is a highly prevalent condition. Stricturing phenotype demonstrated association with SIBO. An individualized screening plan followed by the timely treatment for SIBO should be carried out as part of quality of care improvement in CD individuals.

Vague abdominal pain after Roux-en-Y gastric bypass: not always an internal herniation: case report and literature review

Background: Roux-en-Y gastric bypass is a frequently carried out bariatric procedure, proven to be effective in the management of obesity and its accompanying health issues. Following its popularity, admission to the emergency department for abdominal pain is often seen with known early and late onset causes. We present a case of a young woman with vague abdominal pain years after her gastric bypass, who eventually underwent a resection of a 'candy cane' like biliopancreatic blind loop.Methods: A healthy 23-year-old woman has been suffering of vague abdominal complaints after a gastric bypass procedure 4 years earlier. Postprandial pain, diarrhoea and abdominal distension were present at a daily to weekly basis. Several investigations and management options were administered by surgeons, gastroenterologists as well as endocrinologists. On a performed explorative laparoscopy, a large blind loop at the entero-enteric anastomosis was seen and resected.Results: At current follow-up of 15 months the resection of the candy cane like blind end of the biliopancreatic loop resulted in a complete withdrawal of our patient's symptoms. A tentative diagnosis of bacterial overgrowth in the blind loop was made.Conclusions: Abdominal pain after gastric bypass is a frequent cause of admission to the emergency department. Besides the more serious complications, internal hernia is often withheld as possible diagnosis in the differential diagnosis of late onset, postprandial epigastric pain. This case report highlights another possibility. At initial surgery, a candy cane shaped blind loop should be avoided both at the gastro-jejunal as well as the entero-enteric anastomosis.

Non-alcoholic fatty liver disease later diagnosed as myotonic dystrophy

BACKGROUND

Myotonic dystrophy (MD) is sometimes accompanied by metabolic/endocrine disorders, including dyslipidemia, central obesity, and hypogonadism. Due to considerable individual differences in the severity and progression of myopathy, MD patients with minimal-to-mild muscle symptoms might be followed as having other diseases, such as non-alcoholic fatty liver disease (NAFLD).

CASE SUMMARY

A 40-year-old non-obese man without a history of regular ethanol consumption was referred to our hospital due to persistent liver dysfunction and hyperlipidemia. His body mass index was 23.4 kg/m². Liver histology demonstrated macrovesicular steatosis, ballooned hepatocytes with eosinophilic inclusion bodies, and perisinusoidal fibrosis, leading to the diagnosis of non-alcoholic steatohepatitis (NASH). Although he had no discernable muscle pain or weakness, persistently high serum creatine kinase (CK) and myoglobin levels as well as the presence of frontal baldness, a hatched face, history of cataract surgery, and grip myotonia indicated the possibility of MD. Southern blotting of the patient’s DNA revealed the presence of CTG repeats, confirming the diagnosis.

CONCLUSION

When gastroenterologists encounter NAFLD/NASH patients, serum CK should be verified. If hyperCKemia, frontal baldness, a hatched face, history of cataract surgery, and grip myotonia are noted, the possibility of MD may be considered.

Effect of Massa Medicata Fermentata on the Gut Microbiota of Dyspepsia Mice Based on 16S rRNA Technique

Massa Medicata Fermentata (MMF) is a traditional Chinese medicine (TCM) for treating indigestion and its related disorders. This study analyzes the effect of MMF on intestinal microorganisms in dyspepsia mice based on 16S rRNA technology. We take a dyspepsia model caused by a high-protein, high-calorie, high-fat diet. The 60 specific-pathogen free Kunming (SPF KM) mice were randomly divided into a model group (n=12), an MMF group (LSQ group, n=12), a Jianweixiaoshi group (JWXS group, n=12), a domperidone group (DP group, n=12), and a blank group (n=12). On the seventh day of administration, mice were fasted and deprived of water. After 24 h, take the second feces of stress defecation in mice under strict aseptic conditions and quickly transfer them to a sterile cryotube. This study comprehensively evaluates the α-diversity, β-diversity, flora abundance and composition of each group of mice's intestinal microorganisms, and their correlation with functional dyspepsia based on the 16S rRNA gene sequencing technology. After modeling, some dyspepsia reactions, proximal gastric relaxation reduction, and intestinal microflora changes were noted. Dyspepsia mice showed dyspepsia reactions and proximal gastric relaxation reduction, characterized by a significant decrease of contents of gastrin (P < 0.01) and cholinesterase (P < 0.01). MMF can improve dyspepsia symptoms and promote proximal gastric relaxation. Significant intestinal flora disorders were found in dyspepsia mice, including downregulation of Bacteroidetes, Lactobacillus, and Prevotellaceae and upregulation of Proteobacteria, Verrucomicrobia, Epsilonbacteraeota, Firmicutes, Lachnospiraceae NK4A136 group, and Lachnospiraceae. MMF could alleviate intestinal microflora disturbance, and the regulation effect of MMF on Bacteroidetes, Verrucomicrobia, and Epsilonbacteraeota was more reliable than that of Jianweixiaoshi tables and domperidone. The intestinal microflora may be correlated with the promoted digestion of MMF.

The Relevance of Thiamine Evaluation in a Practical Setting

Thiamine is a crucial cofactor involved in the maintenance of carbohydrate metabolism and participates in multiple cellular metabolic processes. Although thiamine can be obtained from various food sources, some common food groups are deficient in thiamine, and it can be denatured by high temperature and pH. Additionally, different drugs can alter thiamine metabolism. In addition, the half-life of thiamine in the body is between 1 and 3 weeks. All these factors could provide an explanation for the relatively short period needed to develop thiamine deficiency and observe the consequent clinical symptoms. Thiamine deficiency could lead to neurological and cardiological problems. These clinical conditions could be severe or even fatal. Marginal deficiency too may promote weaker symptoms that might be overlooked. Patients undergoing upper gastrointestinal or pancreatic surgery could have or develop thiamine deficiency for many different reasons. To achieve the best outcome for these patients, we strongly recommend the execution of both an adequate preoperative nutritional assessment, which includes thiamine evaluation, and a close nutritional follow up to avoid a nutrient deficit in the postoperative period.

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.

Small intestinal bacterial overgrowth as a cause of protracted wound healing and vitamin D deficiency in a spinal cord injured patient with a sacral pressure sore: a case report

BACKGROUND

Pressure sores are sometimes refractory to treatment, often due to malnutrition. Small intestinal bacterial overgrowth (SIBO) obstructs absorption in the digestive tract and causes malnutrition. However, little is known about the association between pressure sore wound healing and SIBO. Here, we report a case of a patient with a refractory sacral pressure sore and SIBO.

CASE PRESENTATION

A 66-year-old woman who was spinal cord injured 14 years before visiting our hospital presented with the chief complaint of a sacral pressure sore, 10.0 × 6.5 cm in size, which was refractory to treatment. Physical examination showed abdominal distension and emaciation, with a body mass index of 15. Further examination revealed elevated serum alkaline phosphatase (1260 U/L), bilateral tibial fracture, multiple rib fracture, and osteoporosis. We diagnosed the patient with osteomalacia with vitamin D deficiency. Despite oral supplementation, serum levels of calcium, phosphorous, and vitamin D remained low. Also, despite concentrative wound therapy for the sacral pressure sore by plastic surgeons, no wound healing was achieved. Due to a suspicion of disturbances in nutrient absorption, we performed bacterial examination of collected gastric and duodenal fluid, which showed high numbers of bacteria in gastric content (10⁴ E. coli, 10⁵ Streptococcus species, and 10⁵ Neisseria species) and duodenal content (10⁶ E. coli, 10⁴ Candida glabrata). Therefore, we diagnosed the patient with SIBO and started selective decontamination of the digestive tract using polymyxin B sulfate and amphotericin B. After starting treatment for SIBO, the sacral pressure sore began to heal and was nearly healed after 285 days. The patient's serum levels of calcium, phosphorous, vitamin D, and other fat-soluble vitamins also gradually increased after starting treatment for SIBO.

CONCLUSION

We report a case of a patient with a refractory sacral pressure sore that healed after starting treatment for SIBO. We conclude that SIBO may be an overlooked cause of malnutrition and poor wound healing in patients with chronic pressure sores.

The Role of Fecal Calprotectin in Patients with Systemic Sclerosis and Small Intestinal Bacterial Overgrowth (SIBO)

Fecal calprotectin (FC) is a quick, cost-effective, and noninvasive test, which is used to diagnose patients with active inflammatory bowel diseases (IBD). Recent studies suggest the possible predictive role of FC in the diagnosis of small intestinal bacterial overgrowth (SIBO) in patients with systemic sclerosis (SSc). This study aimed to assess the predictive value of FC in SSc patients and its’ possible use as a SIBO marker. A total of 40 SSc patients and 39 healthy volunteers were enrolled in the study. All subjects completed questionnaires evaluating gastrointestinal symptoms, FC measurements, and lactulose hydrogen breath test (LHBT) assessing SIBO presence. After rifaximin treatment, patients with SIBO underwent the same diagnostic procedures. Significantly higher FC values were observed in the study group compared to controls (97 vs. 20 μg/g; p < 0.0001) and in SSc patients diagnosed with SIBO compared to SSc patients without SIBO (206 vs. 24 μg/g; p = 0.0010). FC turned out to be a sensitive (94.12%) and specific (73.68%) marker in the detection of SIBO in patients with SSc (AUC = 0.82, 95% CI = 0.66–0.93; p < 0.0001). Our study suggests the potential value of FC in SSc in detecting gastrointestinal impairment and its promising role as an additional diagnostic tool for SIBO.

Metabolic multistability and hysteresis in a model aerobe-anaerobe microbiome community

Major changes in the microbiome are associated with health and disease. Some microbiome states persist despite seemingly unfavorable conditions, such as the proliferation of aerobe-anaerobe communities in oxygen-exposed environments in wound infections or small intestinal bacterial overgrowth. Mechanisms underlying transitions into and persistence of these states remain unclear. Using two microbial taxa relevant to the human microbiome, we combine genome-scale mathematical modeling, bioreactor experiments, transcriptomics, and dynamical systems theory to show that multistability and hysteresis (MSH) is a mechanism describing the shift from an aerobe-dominated state to a resilient, paradoxically persistent aerobe-anaerobe state. We examine the impact of changing oxygen and nutrient regimes and identify changes in metabolism and gene expression that lead to MSH and associated multi-stable states. In such systems, conceptual causation-correlation connections break and MSH must be used for analysis. Using MSH to analyze microbiome dynamics will improve our conceptual understanding of stability of microbiome states and transitions between states.

Small Intestinal Bacterial Overgrowth Diagnosed by a Breath Test and Improved by Rifaximin in a Patient with Hepatic Encephalopathy and Alcoholic Liver Cirrhosis

A 66-year-old Japanese man was admitted to our hospital with grade 2 hepatic encephalopathy (HE). Abdominal computed tomography and laboratory examinations revealed decompensated liver cirrhosis. Intravenous administration of branched-chain amino acids immediately ameliorated the HE, and lactulose was initiated. However, a breath test revealed small intestinal bacterial overgrowth (SIBO); therefore, rifaximin was additionally initiated. The breath test was repeated after discharge, when no evidence of SIBO or overt HE was identified. This case suggested that a breath test is effective for the identification of SIBO and that the administration of a poorly absorbed antibiotic should be considered in SIBO-positive HE patients taking lactulose.

NOD2 in hepatocytes engages a liver-gut axis to protect against steatosis, fibrosis, and gut dysbiosis during fatty liver disease in mice

Obesity promotes nonalcoholic fatty liver disease (NAFLD). The intestinal microbiota contributes to NAFLD progression through a gut-to-liver pathway that promotes inflammation and fibrosis. Gut microbiota-derived factors can travel to the liver and activate immune responses in liver resident cells to promote inflammation and NAFLD. Little is known about bacterial sensors or immune responses that can protect against NAFLD. We tested whether the bacterial cell wall sensor nucleotide-binding oligomerization domain-containing (NOD)2 protects against diet-induced NAFLD in mice. Whole body deletion of NOD2 exacerbated liver steatosis and fibrosis in mice fed a NAFLD-promoting diet. Mice with a hepatocyte-specific deletion of NOD2 (Nod2^-/-HKO) also had higher liver steatosis and fibrosis compared with littermate wild-type mice (WT) fed a NAFLD-promoting diet. Hepatocyte-specific NOD2 deletion altered the composition of the gut microbiome. Nod2^-/-HKO mice had increased relative abundance of Clostridiales and lower Erysipelotrichaceae among other changes in cecal bacteria compared with littermate WT mice. Hepatocyte-specific NOD2 deletion altered a transcriptional program of liver inflammation, metabolism, and fibrosis. Nod2^-/-HKO mice had higher levels of transcripts involved in lipid and cholesterol metabolism. Nod2^-/-HKO mice had higher transcript levels of transforming growth factor-β and collagen isoforms, which coincided with higher levels of liver collagen compared with WT mice. These data show that bacterial cell wall sensing within hepatocytes can engage retrograde cross-talk from the liver to the gut, where liver immunity communicates with the gut to influence the intestinal host-microbe relationship during diet-induced NAFLD, and NOD2 within the hepatocyte confers protection from liver steatosis and fibrosis.

Ileocecal valve syndrome and vitamin b12 deficiency after surgery: a multicentric prospective study

Patients undergoing colon resection are often concerned about their functional outcomes after surgery. The primary aim of this prospective, multicentric study was to assess the intestinal activity and health-related quality-of-life (HRQL) after ileocecal valve removal. The secondary aim was to evaluate any vitamin B12 deficiency. The study included patients undergoing right colectomy, extended right colectomy and ileocecal resection for either neoplastic or benign disease. Selected items of GIQLI and EORTC QLQ-CR29 questionnaires were used to investigate intestinal activity and HRQL before and after surgery. Blood samples for vitamin B12 level were collected before and during the follow-up period. The empirical rule effect size (ERES) method was used to explain the clinical effect of statistical results. Linear mixed effect (LME) model for longitudinal data was applied to detect the most important parameters affecting the total score. A total of 158 patients were considered. Applying the ERES method, the analysis of both questionnaires showed clinically and statistically significant improvement of HRQL at the end of the follow-up period. Applying the LME model, worsening of HRQL was correlated with female gender and ileum length when using GIQLI questionnaire, and with female gender, open approach, and advanced cancer stage when using the EORTC QLQ-CR29 questionnaire. No significant deficiency in vitamin B12 levels was observed regardless of the length of surgical specimen. In our series, no deterioration of HRQL and no vitamin B12 deficiency were found during the follow-up period. Nevertheless, warning patients about potential changes in bowel habits is mandatory. In our series, no deterioration of HRQL and no vitamin B12 deficiency were found during the follow-up period. Nevertheless, warning patients about potential changes in bowel habits is mandatory.

The duodenal microbiome is altered in small intestinal bacterial overgrowth

Small intestinal bacterial overgrowth (SIBO) is highly prevalent and is associated with numerous gastrointestinal disorders, but the microbes involved remain poorly defined. Moreover, existing studies of microbiome alterations in SIBO have utilized stool samples, which are not representative of the entire gastrointestinal tract. Therefore, we aimed to determine and compare the duodenal microbiome composition in SIBO and non-SIBO subjects, using duodenal aspirates from subjects undergoing standard-of-care esophagogastroduodenoscopy without colon preparation. Using the recently-redefined cutoff for SIBO of >103 colony forming units per milliliter (CFU/mL), 42 SIBO and 98 non-SIBO subjects were identified. Duodenal samples from SIBO subjects had 4x103-fold higher counts than non-SIBO subjects when plated on MacConkey agar (P<0.0001), and 3.8-fold higher counts when plated on blood agar (P<0.0001). Twenty subjects had also undergone lactulose hydrogen breath tests (LHBTs), of whom 7/20 had SIBO. At the 90-minute timepoint, 4/7 SIBO subjects had positive LHBTs (rise in hydrogen (H2) ≥ 20 ppm above baseline), as compared to 2/13 non-SIBO subjects. 16S ribosomal RNA (rRNA) sequencing revealed that SIBO subjects had 4.31-fold higher relative abundance of Proteobacteria (FDR P<0.0001) and 1.64-fold lower Firmicutes (P<0.0003) than non-SIBO subjects. This increased relative abundance of Proteobacteria correlated with decreased α-diversity in SIBO subjects (Spearman R = 0.4866, P<0.0001) Specific increases in class Gammaproteobacteria correlated with the area-under-the-curve for H2 for 0-90 mins during LHBT (R = 0.630, P = 0.002). Increases in Gammaproteobacteria resulted primarily from higher relative abundances of the family Enterobacteriaceae (FDR P<0.0001), which correlated with the symptom of bloating (Spearman R = 0.185, 2-tailed P = 0.028). Increases in family Aeromonadaceae correlated with urgency with bowel movement (Spearman R = 0.186, 2-tailed P = 0.028). These results validate the >103 CFU/mL cutoff for the definition of SIBO, and also reveal specific overgrowth of Proteobacteria in SIBO vs. non-SIBO subjects, coupled with an altered Proteobacterial profile that correlates with symptom severity. Future research may elucidate host-microbiome interactions underlying these symptoms in SIBO patients.

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.

The role of small intestinal bacterial overgrowth and false positive diagnosis of lactose intolerance in southwest Hungary-A retrospective observational study

Background

Lactose intolerance is a frequent gastrointestinal disease affecting 47% of the Eastern European population. Small intestinal bacterial overgrowth (SIBO) leads to carbohydrate malabsorption and therefore to false results during lactose breath and tolerance tests.

Objectives

We aimed to assess the prevalence of lactose maldigestion and intolerance in Hungary and to investigate the role of combined diagnostic method and testing for SIBO in reducing false results.

Methods

We retrospectively analyzed data from 264 adult symptomatic patients who underwent 50g lactose breath and tolerance tests in parallel over a one-year period at our center. A ≥20 ppm elevation of H₂ or less than 1.1 mmol/l rise of blood glucose was diagnostic for lactose maldigestion. Patients with maldigestion who had symptoms during the test were defined as lactose intolerant. Patients with an early (≤90 min) significant (≥20 ppm) rise of H₂ during lactose and/or lactulose breath tests were determined to have SIBO. Patients with slow/rapid oro-cecal transit and inappropriate preparation before the test were excluded.

Results

49.6% of the 264 patients had lactose maldigestion, and 29.5% had lactose intolerance. The most frequent symptom was bloating (22.7%), while 34.8% of the study population and 60% of the symptomatic patients had SIBO. In 9.1% and 9.8% of the patients, the lactose breath and tolerance test alone gave false positive result compared with the combined method. SIBO was present in 75% of the false positives diagnosed with breath test only.

Conclusions

The prevalence of lactose intolerance is lower in Hungary compared to the Eastern European value (29.5% vs 47%), so it is worth performing a population-based prospective analysis in this area. A combination of lactose breath and tolerance tests and the careful monitoring of results (with early H2 rise, lactulose breath test, etc.) can decrease the false cases caused by e.g. SIBO.

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.

Duodenal and rectal mucosal microbiota related to small intestinal bacterial overgrowth in diarrhea-predominant irritable bowel syndrome

BACKGROUND AND AIM

Small intestinal bacterial overgrowth (SIBO) has been proposed as an etiologic factor in irritable bowel syndrome, particularly the diarrhea-predominant subtype (IBS-D). We aimed to identify potential intestinal microbial pattern in IBS-D patients with SIBO.

METHODS

Diarrhea-predominant irritable bowel syndrome patients fulfilling Rome III criteria were recruited and randomly divided into an exploratory cohort (57 cases) and a validation cohort (20 cases). SIBO was identified according to standard glucose hydrogen breath test. For 16S rRNA gene sequencing, samples of duodenal mucosa, duodenal fluid, rectal mucosa, and fresh feces were collected and performed. The α and β diversity, as well as differences in microbial composition and function, in SIBO⁺ and SIBO^- IBS-D subjects were evaluated.

RESULTS

The microbial diversity and composition obviously differed between SIBO⁺ and SIBO^- IBS-D in duodenal and rectal mucosa but not in duodenal fluid and fresh feces. For rectal mucosal microbiota, it displayed markedly reduced aerobe and Gram-negative bacteria and increased facultative anaerobe and Gram-positive bacteria, moreover, altered functions of microbial metabolism in SIBO⁺ IBS-D. Significantly higher rectal mucosa-related microbial dysbiosis index was observed in SIBO⁺ IBS-D, and a cut-off value at -0.37 had a sensitivity of 56.55% and specificity of 90.91% to identify the SIBO in IBS-D subjects.

CONCLUSIONS

Mucosal microbiota, rather than luminal bacteria, has a more apparent dysbiosis in SIBO⁺ IBS-D patients relative to those without SIBO. Rectal mucosa-associated microbiota may act as a potential predictor of SIBO in IBS-D patients.

Small Bowel Dysmotility, Pseudoobstruction, and Functional Correlation with Histopathology: Lessons Learned

PURPOSE OF REVIEW

Small bowel dysmotility is a broad heterogeneous term that encompasses a wide range of gastrointestinal disorders resulting from abnormal gut motility. Chronic intestinal pseudo-obstruction (CIPO) is a severe, rare, and complex small bowel motility disorder at the extreme end of this spectrum. It is characterized by failure of the intestinal tract to propel contents, which results in signs and symptoms of bowel obstruction albeit in the absence of any obstructive lesion(s). In this article, we discuss up-to-date diagnostic techniques, management options, and histopathological findings in CIPO.

RECENT FINDINGS

We will emphasize the latest diagnostic methodologies and therapeutic options as well as enteric histopathologic abnormalities in patients with CIPO. CIPO continues to be a clinical challenge. Several novel pharmacological agents hold promise including gastrointestinal hormone agonists and prokinetics. Furthermore, histopathologic findings may help guide therapy and provide further prognostic significance. At present, nutritional support, symptom management, and avoidance of long-term complications are the mainstay of treatment in CIPO.

Association between increased breath hydrogen methane concentration and prevalence of glucose intolerance in acute pancreatitis

Pancreatic damage, in the form of pancreatitis, intestinal bacteria and glucose imbalance could be interrelated. The aim of this study was to investigate the breath hydrogen (H₂) and methane (CH₄), which can indicate small intestinal bacterial overgrowth (SIBO) status, and assess the link between SIBO and glucose tolerance in patients with acute pancreatitis (AP). This prospective study enrolled 75 patients who were admitted for AP. A glucose breath test (GBT) which detects breath hydrogen H₂ and CH₄ for SIBO with an oral glucose tolerance test (OGTT) for 120 min was simultaneously performed to determine SIBO and glucose tolerance. Patient demographic data, laboratory test data, and computed tomography severity index (CTSI) were also evaluated. The levels of total breath H₂ and CH₄ in patients with AP were significantly higher than those in controls, respectively (p < 0.01). There were no significant differences in the incidence of SIBO between patients with AP and controls. The OGTT indicated that blood glucose levels at 30, 60, 90, and 120 min were higher in SIBO-positive patients than in SIBO-negative patients. No significant differences in CTSI, patient demographic data or laboratory test data were observed between the two groups. Breath H₂ and CH₄ concentrations are relatively higher in patients with AP, indicating a correlation between high levels of intestinal bacteria and AP. Furthermore, higher breath H₂ and CH₄ concentrations appear to be associated with oral glucose intolerance, with hyperglycemia occurring in patients with AP.

ACG Clinical Guideline: Small Intestinal Bacterial Overgrowth

Small intestinal bacterial overgrowth is defined as the presence of excessive numbers of bacteria in the small bowel, causing gastrointestinal symptoms. This guideline statement evaluates criteria for diagnosis, defines the optimal methods for diagnostic testing, and summarizes treatment options for small intestinal bacterial overgrowth. This guideline provides an evidence-based evaluation of the literature through the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) process. In instances where the available evidence was not appropriate for a formal GRADE recommendation, key concepts were developed using expert consensus.

The correlation between intestinal mucosal lesions and hepatic dysfunction in patients without chronic liver disease

Patients with cirrhosis are known to develop small bowel mucosal lesions. However, the occurrence of mucosal lesions in patients with abnormal liver function test results in the absence of chronic liver disease has not been fully evaluated. This study aims to examine the association between small bowel endoscopic lesions and liver dysfunction in patients without confirmed chronic liver disease.Two hundred ninety six consecutive patients who met the selection criteria underwent capsule endoscopy. The severity of the small intestinal mucosal lesions was evaluated quantitatively using the Lewis scoring system, and hepatic dysfunction was evaluated using an algorithm-based combination scoring system with 8 individual serological markers.Small bowel lesions were observed in 121 patients (40.88%). Hepatic dysfunction was significantly more prevalent in patients with small bowel lesions than in those without lesions (33.1%; 40/121 and 5.7%; 10/175, respectively; P < .001). The mean serum ALT and AST levels were significantly higher in patients with small bowel lesions than in those without lesions (P = .007 and P = .004, respectively). The mean scores for AST to Platelet Ratio Index, Forns Index, S-Index, Fibrosis-4 Index and BARD were significantly higher in patients with small bowel lesions than those without lesions. The Lewis score significantly and positively correlated with the Forns Index (P = .008) and the FIB-4 Index (P = .006).There is a close correlation between small intestinal mucosal lesions and hepatic dysfunction. The severity of hepatic dysfunction is directly proportional to the severity of the small intestinal mucosal lesions in patients without confirmed chronic liver disease.

Evidence of altered mucosa-associated and fecal microbiota composition in patients with Irritable Bowel Syndrome

Altered bacterial composition and small intestinal bacterial overgrowth (SIBO) may be associated with irritable bowel syndrome (IBS). This study aimed to determine the fecal and mucosa-associated bacterial composition along the gastrointestinal (GI) tract and to assess SIBO in IBS. Bacterial composition of feces, and mucosa of the duodenum and sigmoid colon was determined by 16S rRNA-amplicon-sequencing. SIBO was evaluated by bacterial culture of duodenal aspirate, glucose and lactulose breath tests. Mucosal antibacterial gene expression was assessed by PCR Array. The bacterial profiles of feces and the mucosa of sigmoid colon, but not duodenum, differed between IBS patients (n = 17) and HS (n = 20). The IBS specific bacterial profiles were linked to the colonic antibacterial gene expression. Fecal bacterial profile differed between IBS subtypes, while the mucosa-associated bacterial profile was associated with IBS symptom severity and breath tests results at baseline (H₂ and/or CH₄ ≥ 15 ppm). The prevalence of SIBO was similar between IBS patients and HS. This study demonstrates that alterations in the bacterial composition of the sigmoid colon of IBS patients were linked to symptoms and immune activation. While breath tests reflected the mucosa-associated bacterial composition, there was no evidence for high prevalence of SIBO or small intestinal bacterial alterations in IBS.

THE IMPACT OF SMALL INTESTINAL BACTERIAL OVERGROWTH ON THE GROWTH OF CHILDREN AND ADOLESCENTS

Objective:

To evaluate the association between small intestinal bacterial overgrowth (SIBO) and weight and height impairment in children and adolescents with gastroenterology diseases.

Methods:

Observational and retrospective study. All 162 patients aged less than 19 years old who underwent breath test in search of SIBO between 2011 and 2016 were studied. Breath test was collected after the intake of 10 grams of lactulose. The concentration of hydrogen and methane was measured for 180 minutes after the beginning of the test by 12i QuinTronMicroLyzer device.

Results:

SIBO was identified in 51 (31.5%) patients. There was no difference between the age of those with (mean=8.7y.o; 25^th and 75^th percentile: 4.6 and 11.3) and without (mean=7.9y.o 25^th and 75^th percentile: 4.8 and 12.2) SIBO (p=0.910). There was no association between gender and SIBO (male 26.3% vs. female 36.3%, p=1.00). A lower median of height-for-age Z score (mean=-1.32; 25^th and 75^th percentile: -2.12 and -0.08 vs. mean=-0.59; 25^th and 75^th percentile: -1.57 and 0.22; p=0.04) was demonstrated in children with SIBO when compared with children without it. There was no difference between the BMI-for-age Z score of patients with (mean=-0.48) and without SIBO (mean=-0.06) (p=0.106). The BMI of patients with SIBO (median=15.39) was lower than of those without it (median=16.06); however, the statistical analysis was not significant (p=0.052). The weight-for-age Z score was lower in patients with SIBO (mean=-0.96) than in those without SIBO (mean=-0.22) (p=0.02)

Conclusions:

Children and adolescents with SBIO associated with diseases of the gastrointestinal tract have lower weight and height values.

Clinical Management of the Microbiome in Irritable Bowel Syndrome

Background

A growing body of evidence suggests that dysbiosis contributes to the onset and symptomatology of irritable bowel syndrome (IBS) and other functional bowel disorders. Changes to the gastrointestinal microbiome may contribute to the underlying pathophysiology of IBS.

Methods

The present review summarizes the potential effects of microbiome changes on GI transit, intestinal barrier function, immune dysregulation and inflammation, gut–brain interactions and neuropsychiatric function.

Results

A multimodal approach to IBS management is recommended in accordance with current Canadian guidelines. Pharmacologic treatments are advised to target the presumed underlying pathophysiological mechanism, such as dysregulation of GI transit, peristalsis, intestinal barrier function and pain signalling. The management plan for IBS may also include treatments directed at dysbiosis, including dietary modification and use of probiotics, which may promote the growth of beneficial bacteria, affect intestinal gas production and modulate the immune response; and the administration of periodic short courses of a nonsystemic antibiotic such as rifaximin, which may re-establish microbiota diversity and improve IBS symptoms.

Conclusion

Dysregulated host–microbiome interactions are complex and the use of microbiome-directed therapies will necessarily be empiric in individual patients. A management algorithm comprising microbiome- and nonmicrobiome-directed therapies is proposed.

Canadian Association of Gastroenterology Clinical Practice Guideline on the Management of Bile Acid Diarrhea

BACKGROUND & AIMS

Chronic diarrhea affects about 5% of the population overall. Altered bile acid metabolism is a common but frequently undiagnosed cause.

METHODS

We performed a systematic search of publication databases for studies of assessment and management of bile acid diarrhea (BAD). The certainty (quality) of evidence and strength of recommendations were rated according to the Grading of Recommendation Assessment, Development and Evaluation approach. Patient population, intervention, comparator, and outcome questions were developed through an iterative process and were voted on by a group of specialists.

RESULTS

The certainty of evidence was generally rated as very low. Therefore, 16 of 17 recommendations are conditional. In patients with chronic diarrhea, consideration of risk factors (terminal ileal resection, cholecystectomy, or abdominal radiotherapy), but not additional symptoms, was recommended for identification of patients with possible BAD. The group suggested testing using ⁷⁵selenium homocholic acid taurine (where available) or 7α-hydroxy-4-cholesten-3-one, including patients with irritable bowel syndrome with diarrhea, functional diarrhea, and Crohn's disease without inflammation. Testing was suggested over empiric bile acid sequestrant therapy (BAST). Once remediable causes are managed, the group suggested cholestyramine as initial therapy, with alternate BAST when tolerability is an issue. The group suggested against BAST for patients with extensive ileal Crohn's disease or resection and suggested alternative antidiarrheal agents if BAST is not tolerated. Maintenance BAST should be given at the lowest effective dose, with a trial of intermittent, on-demand administration, concurrent medication review, and reinvestigation for patients whose symptoms persist despite BAST.

CONCLUSIONS

Based on a systematic review, BAD should be considered for patients with chronic diarrhea. For patients with positive results from tests for BAD, a trial of BAST, initially with cholestyramine, is suggested.

Nanomaterial-based gas sensors used for breath diagnosis

Gas-sensing applications commonly use nanomaterials (NMs) because of their unique physicochemical properties, including a high surface-to-volume ratio, enormous number of active sites, controllable morphology, and potential for miniaturisation.

Role of Small Intestinal Bacterial Overgrowth (SIBO) and Inflammation in Obese Children

Knowledge of the real incidence of small intestinal bacterial overgrowth (SIBO) in obese children and its role in obesity development seems essential for a more effective approach to the treatment of this condition. In this prospective, single-blind study, presence of SIBO was evaluated in a group of children with overweight/obesity. A blood sample for evaluation of cytokine profile was collected to establish the potential relationship with inflammatory condition and lactulose breath test (LBT) to diagnose SIBO was performed. A total of 36 patients with excess of adipose tissue were recruited. Among them, 16 (44.4%) were overweight and 20 (45.6%) were obese. Overall, 26 (72.2%) children had a positive LBT and were considered suffering from SIBO, 12 (75.0%) among those overweight and 14 (70.0%) among those obese. Measurement of cytokines (IL-1α, IL-1β, IL-4, IL-6, IL-7, IL-8, IL-10, IL-12p40, IL-12p70, IL-17, IFN-α2, IFN-γ, TNF-α), cytokine antagonists (IL-1ra), chemokines (IP10, MCP-1, MIP1α, MIP1β), and growth factors (EGF, G-CSF, GM-CSF, and VEGF) secreted in culture supernatants by PHA activated-PBMCs revealed that in the study population proinflammatory cytokines IL-1, IL-6, IL-8, IL-12, IFN-γ, IL-18, and TNF-α were high, whereas anti-inflammatory mediators IL-4 and IL-10 were low. However, no significance difference between children with SIBO and those without were evidenced. Evaluation of relationship of severity of SIBO showed a significant positive relationship between EGF or IFN-α2 and H2 but not CH4 levels and an inverse significant relationship with CH4 but not H2. Despite its limitations and further studies are needed, this study seems to indicate that SIBO is extremely common in overweight and obese children and can be demonstrated not only in severely obese subjects but also in moderately overweight patients. The inflammatory state seems to precede obesity development and SIBO does not seem to have relevance in obesity development, with no relationship found between severity of SIBO and inflammatory state.

Gut Microbiota Imbalance Can Be Associated with Non-malabsorptive Small Bowel Shortening Regardless of Blind Loop

INTRODUCTION

Some traditional bariatric surgery procedures may lead to functional gut shortening, which may unsettle the fine-tuned gastrointestinal physiology and affect gut microbiota balance.

PURPOSE

Evaluate the gut microbiota behavior in rat models facing gut shortening due to intestinal bypass.

MATERIALS AND METHODS

Wistar rats (n = 17) were randomly distributed in three groups: (1) sham group (n = 5); (2) blind loop group (n = 6); and (3) resection group (n = 6). Intestinal samples and feces were analyzed to measure bacterial concentrations (small intestinal bacterial overgrowth-SIBO) 12 weeks after the experimental procedures. Bacterial translocation (BT) was investigated in the mesenteric lymph node (MLN), liver, spleen, and lung of the animals. In addition, inflammatory aspects were investigated in their liver and small bowel through histological analysis.

RESULTS

Regardless of blind loop, gut shortening groups recorded similar high level of bacterial concentrations in intestine compartments, greater than that of the sham group (p ≤ 0.05). BT was only observed in the MLN of gut shortening models, with higher percentage in the blind loop group (p ≤ 0.05). The gut and liver histopathological analysis showed similar low-grade chronic inflammation in both gut shortening groups, likely associated with SIBO/BT events.

CONCLUSION

Sustained SIBO/BT was associated with proximal gut shortening in half regardless of blind loop, whereas the GI tract's ability to restore gut microbiota balance after a surgical challenge on the small bowel appears to be linked to the functional remaining gut.

Review of the management of diarrhea syndrome after a bariatric surgery

Obesity is a prevalent health problem in our population. Bariatric surgery is the indicated treatment for severe cases. It is very effective (together with an adequate lifestyle modification) but it is also associated with frequent adverse events. One of the most frequent and disturbing adverse event is diarrhea. Diarrhea after bariatric surgery may be secondary to multiple causes and the physiopathogenic mechanisms may depend on the type of surgery performed. The most frequent diarrhea mechanisms are dumping syndrome, vagotomy, short bowel syndrome, carbohydrate malabsorption, protein malabsorption, alterations of the microbiota, Clostridium difficile infection, bacterial overgrowth, bile salt malabsorption, pancreatic insufficiency, endocrinological disorders, addictive disorders, and other digestive disorders not necessarily related to surgery.

Canadian Association of Gastroenterology Clinical Practice Guideline on the Management of Bile Acid Diarrhea

Background and Aims

Chronic diarrhea affects about 5% of the population overall. Altered bile acid metabolism is a common but frequently undiagnosed cause.

Methods

We performed a systematic search of publication databases for studies of assessment and management of bile acid diarrhea (BAD). The certainty (quality) of evidence and strength of recommendations were rated according to the Grading of Recommendation Assessment, Development and Evaluation approach. Patient population, intervention, comparator and outcome questions were developed through an iterative process and were voted on by a group of specialists.

Results

The certainty of evidence was generally rated as very low. Therefore, 16 of 17 recommendations are conditional. In patients with chronic diarrhea, consideration of risk factors (terminal ileal resection, cholecystectomy or abdominal radiotherapy), but not additional symptoms, was recommended for identification of patients with possible BAD. The group suggested testing using ⁷⁵selenium homocholic acid taurine (where available) or 7α-hydroxy-4-cholesten-3-one, including patients with irritable bowel syndrome with diarrhea, functional diarrhea and Crohn's disease without inflammation. Testing was suggested over empiric bile acid sequestrant therapy (BAST). Once remediable causes are managed, the group suggested cholestyramine as initial therapy, with alternate BAST when tolerability is an issue. The group suggested against BAST for patients with extensive ileal Crohn's disease or resection and suggested alternative antidiarrheal agents if BAST is not tolerated. Maintenance BAST should be given at the lowest effective dose, with a trial of intermittent, on-demand administration, concurrent medication review and reinvestigation for patients whose symptoms persist despite BAST.

Conclusions

Based on a systematic review, BAD should be considered for patients with chronic diarrhea. For patients with positive results from tests for BAD, a trial of BAST, initially with cholestyramine, is suggested.

British Society of Gastroenterology consensus guidelines on the management of inflammatory bowel disease in adults

Ulcerative colitis and Crohn's disease are the principal forms of inflammatory bowel disease. Both represent chronic inflammation of the gastrointestinal tract, which displays heterogeneity in inflammatory and symptomatic burden between patients and within individuals over time. Optimal management relies on understanding and tailoring evidence-based interventions by clinicians in partnership with patients. This guideline for management of inflammatory bowel disease in adults over 16 years of age was developed by Stakeholders representing UK physicians (British Society of Gastroenterology), surgeons (Association of Coloproctology of Great Britain and Ireland), specialist nurses (Royal College of Nursing), paediatricians (British Society of Paediatric Gastroenterology, Hepatology and Nutrition), dietitians (British Dietetic Association), radiologists (British Society of Gastrointestinal and Abdominal Radiology), general practitioners (Primary Care Society for Gastroenterology) and patients (Crohn's and Colitis UK). A systematic review of 88 247 publications and a Delphi consensus process involving 81 multidisciplinary clinicians and patients was undertaken to develop 168 evidence- and expert opinion-based recommendations for pharmacological, non-pharmacological and surgical interventions, as well as optimal service delivery in the management of both ulcerative colitis and Crohn's disease. Comprehensive up-to-date guidance is provided regarding indications for, initiation and monitoring of immunosuppressive therapies, nutrition interventions, pre-, peri- and postoperative management, as well as structure and function of the multidisciplinary team and integration between primary and secondary care. Twenty research priorities to inform future clinical management are presented, alongside objective measurement of priority importance, determined by 2379 electronic survey responses from individuals living with ulcerative colitis and Crohn's disease, including patients, their families and friends.

British Society of Gastroenterology consensus guidelines on the management of inflammatory bowel disease in adults

Ulcerative colitis and Crohn's disease are the principal forms of inflammatory bowel disease. Both represent chronic inflammation of the gastrointestinal tract, which displays heterogeneity in inflammatory and symptomatic burden between patients and within individuals over time. Optimal management relies on understanding and tailoring evidence-based interventions by clinicians in partnership with patients. This guideline for management of inflammatory bowel disease in adults over 16 years of age was developed by Stakeholders representing UK physicians (British Society of Gastroenterology), surgeons (Association of Coloproctology of Great Britain and Ireland), specialist nurses (Royal College of Nursing), paediatricians (British Society of Paediatric Gastroenterology, Hepatology and Nutrition), dietitians (British Dietetic Association), radiologists (British Society of Gastrointestinal and Abdominal Radiology), general practitioners (Primary Care Society for Gastroenterology) and patients (Crohn's and Colitis UK). A systematic review of 88 247 publications and a Delphi consensus process involving 81 multidisciplinary clinicians and patients was undertaken to develop 168 evidence- and expert opinion-based recommendations for pharmacological, non-pharmacological and surgical interventions, as well as optimal service delivery in the management of both ulcerative colitis and Crohn's disease. Comprehensive up-to-date guidance is provided regarding indications for, initiation and monitoring of immunosuppressive therapies, nutrition interventions, pre-, peri- and postoperative management, as well as structure and function of the multidisciplinary team and integration between primary and secondary care. Twenty research priorities to inform future clinical management are presented, alongside objective measurement of priority importance, determined by 2379 electronic survey responses from individuals living with ulcerative colitis and Crohn's disease, including patients, their families and friends.

High occurrence of small intestinal bacterial overgrowth in primary biliary cholangitis

BACKGROUND

Primary biliary cholangitis (PBC) is a chronic autoimmune liver disease affecting mainly middle-aged women. An alteration in intestinal motility has been well documented in cirrhosis predisposing to small intestinal bacterial overgrowth (SIBO). Patients with PBC frequently complain of various gastrointestinal symptoms compatible with SIBO. No study has specifically been published to this day to determine the occurrence of SIBO in PBC. Our objective was to determine the prevalence of SIBO in patients with PBC.

METHODS

Retrospective study from 2010 to 2018. All patients diagnosed with PBC during this period had a systematic screening for SIBO in their diagnostic workup. The diagnosis of SIBO was made by a carbohydrate breath test (lactulose and/or glucose). Clinical and paraclinical factors of patients were compared with a control group of healthy subjects.

KEY RESULTS

Ninety-eight subjects were included in the study (mean age 49, range 21-88 years) including 58 patients with PBC and 40 healthy subjects. The PBC group was older than the control group (mean age 56, range 31-88 vs 39, range 21-62 years; P < .001), but identical for gender and body mass index. The prevalence of SIBO was higher in PBC versus controls (32.8% vs 2.5%; P < .001). The PBC group with SIBO had significantly more diarrhea (78.9% vs 35.9%; P < .05) than the PBC group without SIBO, but the prevalence of abdominal pain and bloating was similar.

CONCLUSIONS & INFERENCES

The high occurrence of SIBO in PBC may explain some of the frequently reported gastrointestinal symptoms. This study justifies the systematic screening for SIBO in PBC.

Intestinal Microbiota of Grass Carp Fed Faba Beans: A Comparative Study

Many reports of the intestinal microbiota of grass carp have addressed the microbial response to diet or starvation or the effect of microbes on metabolism; however, the intestinal microbiota of crisp grass carp has yet to be elucidated. Moreover, the specific bacteria that play a role in the crispiness of grass carp fed faba beans have not been elucidated. In the present study, 16S sequencing was carried out to compare the intestinal microbiota in the fore-, mid- and hind-intestine segments of grass carp following feeding with either faba beans or formula feed. Our results showed that (1) the hind-intestine presented significant differences in diversity relative to the fore- or midintestine and (2) faba beans significantly increased the diversity of intestinal microbiota, changed the intestinal microbiota structure (Fusobacteria was reduced from 64.26% to 18.24%, while Proteobacteria was significantly increased from 17.75% to 51.99%), and decreased the metabolism of energy, cofactors and vitamins in grass carp. Furthermore, at the genus and species levels, Acinetobacter accounted for 15.09% of the microbiota, and Acinetobacter johnsonii and Acinetobacter radioresistens constituted 3.41% and 2.99%, respectively, which indicated that Acinetobacter of the family Moraxellaceae contributed to changes in the intestinal microbiota structure and could be used as a potential biomarker. These results may provide clues at the intestinal microbiota level to understanding the mechanism underlying the crispiness of grass carp fed faba beans.

Bile acid abnormality induced by intestinal dysbiosis might explain lipid metabolism in Parkinson's disease

Intestinal dysbiosis refers to an imbalance in the intestinal flora. The concept of small intestinal bacterial overgrowth (SIBO), a condition of abnormal proliferation of the small intestine microbiota, has been proposed as a form of small intestine dysbiosis. In Parkinson's disease patients, weight loss and metabolic disorders such as lipid abnormalities are frequently encountered. This was a prospective investigation of the presence of SIBO using the lactulose breath test, Parkinson's disease symptoms, medications, abdominal symptoms, and blood data involving 39 Parkinson's disease patients. Of the 39 patients, 19 were positive for SIBO, 16 were negative, and 4 were equivocal. SIBO-positive patients had a significantly smaller dopaminergic drug load (dopamine replacement of Parkinson's disease drug potency) (P = 0.009) and significantly lower serum triglyceride (TG) (P = 0.024) and total bilirubin (P = 0.019) levels. No relationship was seen between the presence or absence of SIBO and motor or abdominal symptoms. The following hypothesis was developed with regard to the possibility that intestinal bacterial overgrowth has various effects that are exhibited via bile acid metabolism in Parkinson's disease patients. Serum bilirubin levels become higher as bilirubin metabolism declines with decreases in the intestinal bacteria. At the same time, bile acid is broken down due to increased intestinal bacteria, and lipid absorption decreases. This induces low serum TG levels and leads to weight loss. By a similar mechanism, there is less absorption of vitamin D as bile acid levels decrease, leading to osteoporosis and fractures. The possibility that some of the non-motor manifestations accompanying Parkinson's disease are caused by intestinal dysbiosis needs to be considered.

Microbiota, Microbial Metabolites, and Barrier Function in A Patient with Anorexia Nervosa after Fecal Microbiota Transplantation

The change in the gut microbiome and microbial metabolites in a patient suffering from severe and enduring anorexia nervosa (AN) and diagnosed with small intestinal bacterial overgrowth syndrome (SIBO) was investigated. Microbial gut dysbiosis is associated with both AN and SIBO, and therefore gut microbiome changes by serial fecal microbiota transplantation (FMT) is a possible therapeutic modality. This study assessed the effects of FMT on gut barrier function, microbiota composition, and the levels of bacterial metabolic products. The patient treatment with FMT led to the improvement of gut barrier function, which was altered prior to FMT. Very low bacterial alpha diversity, a lack of beneficial bacteria, together with a great abundance of fungal species were observed in the patient stool sample before FMT. After FMT, both bacterial species richness and gut microbiome evenness increased in the patient, while the fungal alpha diversity decreased. The total short-chain fatty acids (SCFAs) levels (molecules presenting an important source of energy for epithelial gut cells) gradually increased after FMT. Contrarily, one of the most abundant intestinal neurotransmitters, serotonin, tended to decrease throughout the observation period. Overall, gut microbial dysbiosis improvement after FMT was considered. However, there were no signs of patient clinical improvement. The need for an in-depth analysis of the donor´s stool and correct selection pre-FMT is evident.

Small Intestinal Bacterial Overgrowth in Children: A State-Of-The-Art Review

Small intestinal bacterial overgrowth (SIBO) is a heterogenous and poorly understood entity characterised by an excessive growth of select microorganisms within the small intestine. This excessive bacterial biomass, in turn, disrupts host physiology in a myriad of ways, leading to gastrointestinal and non-gastrointestinal symptoms and complications. SIBO is a common cause of non-specific gastrointestinal symptoms in children, such as chronic abdominal pain, abdominal distention, diarrhoea, and flatulence, amongst others. In addition, it has recently been implicated in the pathophysiology of stunting, a disease that affects millions of children worldwide. Risk factors such as acid-suppressive therapies, alterations in gastrointestinal motility and anatomy, as well as impoverished conditions, have been shown to predispose children to SIBO. SIBO can be diagnosed via culture-dependant or culture-independent approaches. SIBO's epidemiology is limited due to the lack of uniformity and consensus of its diagnostic criteria, as well as the paucity of literature available. Antibiotics remain the first-line treatment option for SIBO, although emerging modalities such as probiotics and diet manipulation could also have a role. Herein, we present a state-of-the-art-review which aims to comprehensively outline the most current information on SIBO in children, with particular emphasis on the gut microbiota.

The Structure and Function of the Human Small Intestinal Microbiota: Current Understanding and Future Directions

Despite growing literature characterizing the fecal microbiome and its association with health and disease, few studies have analyzed the microbiome of the small intestine. Here, we examine what is known about the human small intestinal microbiota in terms of community structure and functional properties. We examine temporal dynamics of select bacterial populations in the small intestine, and the effects of dietary carbohydrates and fats on shaping these populations. We then evaluate dysbiosis in the small intestine in several human disease models, including small intestinal bacterial overgrowth, short-bowel syndrome, pouchitis, environmental enteric dysfunction, and irritable bowel syndrome. What is clear is that the bacterial biology, and mechanisms of bacteria-induced pathophysiology, are enormously broad and elegant in the small intestine. Studying the small intestinal microbiota is challenged by rapidly fluctuating environmental conditions in these intestinal segments, as well as the complexity of sample collection and bioinformatic analysis. Because the functionality of the digestive tract is determined primarily by the small intestine, efforts must be made to better characterize this unique and important microbial ecosystem.

Proton pump inhibitors and dysbiosis: Current knowledge and aspects to be clarified

Proton pump inhibitors (PPIs) are common medications within the practice of gastroenterology. These drugs, which act through the irreversible inhibition of the hydrogen/potassium pump (H+/K+-ATPase pump) in the gastric parietal cells, are used in the treatment of several acid-related disorders. PPIs are generally well tolerated but, through the long-term reduction of gastric acid secretion, can increase the risk of an imbalance in gut microbiota composition (i.e., dysbiosis). The gut microbiota is a complex ecosystem in which microbes coexist and interact with the human host. Indeed, the resident gut bacteria are needed for multiple vital functions, such as nutrient and drug metabolism, the production of energy, defense against pathogens, the modulation of the immune system and support of the integrity of the gut mucosal barrier. The bacteria are collected in communities that vary in density and composition within each segment of the gastrointestinal (GI) tract. Therefore, every change in the gut ecosystem has been connected to an increased susceptibility or exacerbation of various GI disorders. The aim of this review is to summarize the recently available data on PPI-related microbiota alterations in each segment of the GI tract and to analyze the possible involvement of PPIs in the pathogenesis of several specific GI diseases.

Lactulose Breath Testing Can Be a Positive Predictor Before Weight Gain in Participants with Obesity Submitted to Roux-en-Y Gastric Bypass

BACKGROUND

Small intestinal bacterial overgrowth (SIBO) is defined as the colonization of fermentative bacteria in the duodenum and jejunum. The alteration of digestive anatomy promoted by bariatric surgery may be a pre-disposing factor for SIBO. In this context, the prevalence of SIBO in participants undergoing bariatric surgery using Roux-en-Y gastric bypass (BGYR) was evaluated.

METHODS

Participants, both sexes, older than 18 years, were those who (a) had bariatric surgery by the BGYR technique at least 1 year before the data collection and (b) did not use antibiotics recently. The SIBO diagnosis was established through the hydrogen breath test (H₂BT), with intake of lactulose and serial collection of breath samples over 2 h. A test with ≥ 12-point elevation over the basal sample at 60 min after substrate intake was deemed positive.

RESULTS

A total of 18 participants (14 females (77.8%)) were enrolled with a mean age of 50.5 years (range, 23 to 79 years). The interval between surgery and data collection ranged from 5 to 20 years (mean, 11.2 years). The mean preoperative body mass index (BMI) was 44.6 kg/m² (range, 36.7-56.2 kg/m²). The H₂RT with lactulose was positive for SIBO in seven (six female) participants. The participants with negative test measured trough H₂BT with lactulose had a lower mean BMI of 28.69 kg/m², in comparison with the positive group, which presented a mean BMI of 33.04 kg/m² (p value = 0.041).

CONCLUSION

Our data point to a high prevalence of SIBO (38.8%) in patients undergoing BGYR with a value in accordance with the literature. Moreover, the differences in BMI between negative and positive groups by H₂BT with lactulose evidenced a weight gain relapse in participants with SIBO.

Small intestinal microbial dysbiosis underlies symptoms associated with functional gastrointestinal disorders

Small intestinal bacterial overgrowth (SIBO) has been implicated in symptoms associated with functional gastrointestinal disorders (FGIDs), though mechanisms remain poorly defined and treatment involves non-specific antibiotics. Here we show that SIBO based on duodenal aspirate culture reflects an overgrowth of anaerobes, does not correspond with patient symptoms, and may be a result of dietary preferences. Small intestinal microbial composition, on the other hand, is significantly altered in symptomatic patients and does not correspond with aspirate culture results. In a pilot interventional study we found that switching from a high fiber diet to a low fiber, high simple sugar diet triggered FGID-related symptoms and decreased small intestinal microbial diversity while increasing small intestinal permeability. Our findings demonstrate that characterizing small intestinal microbiomes in patients with gastrointestinal symptoms may allow a more targeted antibacterial or a diet-based approach to treatment.

Safety and Efficacy of N-SORB®, a Proprietary KD120 MEC Metabolically Activated Enzyme Formulation: A Randomized, Double-Blind, Placebo-Controlled Study

Background: Enzymes are crucial for all aspects of metabolic function. Digestive enzymes from natural sources have been credited with beneficial effects in the digestion and absorption of food. N-SORB is a novel KD120 multienzyme complex (MEC) of metabolically activated enzymes composed of proteases, amylases, lipases, alpha-galactosidase, and glucoamylase from natural sources. These enzymes are encapsulated in a SK713 SLP (non-GMO soy lecithin phospholipid) absorption technology (Prodosome^®). Objective: This randomized, double-blind placebo-controlled investigation assessed the safety and efficacy of N-SORB KD120 MEC in healthy male and female volunteers on various parameters of the blood, immunity, body composition, physical health, and quality of life following a 90-day intervention. Methods: Forty-six male and female (mean age: 25.8 ± 12.1 years) healthy volunteers were randomly assigned to receive either N-SORB (1 mL, twice daily) or placebo for 90 consecutive days. Complete blood count, as well as blood glucose, liver enzymes, and lipid profile were assessed pre- and post-intervention. Serum cytokine levels were determined by using a Bio-Plex Pro Human Cytokine 8-plex assay and enzyme linked immunosorbent assay (ELISA). Whole body composition analysis was performed by dual-energy x-ray absorptiometry (DEXA) to determine body fat mass, lean mass, and android and gynoid fat. Body weight, blood pressure, and physical health were assessed. Changes in quality of life were examined using the World Health Organization Quality of Life-abbreviated version and sleep quality was assessed using the 24-item Pittsburgh Sleep Quality Index (PSQI) questionnaire. Adverse events were monitored before, during, and after completion of the study. Results: Of the 46 subjects enrolled, a total of 40 subjects successfully completed the study. Compared to placebo, changes in blood cell counts including hematocrit, hemoglobin, mean corpuscular volume, platelets, and lymphocytes provide evidence of some improvement. Quality of life (QOL) parameters showed a small but significant improvement in the N-SORB group. A significant increase was observed in aspartate aminotransferase level in the placebo group at the end of 90 days of treatment; however, no increase was observed in the N-SORB group. No significant changes in blood urea nitrogen, serum creatinine, alkaline phosphatase, alanine aminotransferase, and lipid profile were observed between the placebo and treatment groups before and following intervention. No adverse effects were reported. Conclusions: This randomized, double blind, placebo-controlled clinical study demonstrates that short-term intervention with N-SORB improves the QOL and PSQI in healthy volunteers and did not significantly alter cardiometabolic parameters, lipid profile, or body composition.