BACKGROUND: Methanogens are associated with gut dysmotility in animal models but have not been robustly studied in humans. The WMC assesses regional transit time (TT) and pH in the GI tract.
OBJECTIVE: To study the segmental TT and pH among patients with SIBO or IMO utilizing WMC.
METHODS: We conducted a retrospective study of 207 patients who underwent a glucose or lactulose breath test (BT) and WMC from 2010 to 2022. Diagnosis of SIBO and IMO were based on the 2017 North American consensus criteria. TT and pH were extracted from WMC recordings. We tested for differences in means of continuous variables and frequencies of categorical variables using two-sample t tests, Wilcoxon Rank Sum test, Chi-square, and Fisher exact tests. We used R version 3.3.1 (2016-06-21) for all statistical analyses.
RESULTS: A total of 196 patients met criteria, mean age 47.4 years and 155 (79.1%) females. Of the 86 (43.9%) patients with a positive BT, 42 (58.3%) had IMO only (meeting only CH4 criteria) and 30 (34.9%) met both H2 and CH4 criteria. Colonic TT was longer in patients with a positive BT compared to negative patients (40 h:29 min vs 28 h:51 min, p = 0.028). Small bowel TT and colonic TT were longer in patients with IMO compared to negative patients (SBTT: 5 h:15 min vs 4 h:32 min, p = 0.021; CTT: 44 h:23 min vs 28 h:51 min, p = 0.030). There were no significant differences in segmental pH compared to negative patients.
CONCLUSIONS: To our knowledge, this is the largest study of patients who have undergone both BT and WMC. A positive BT was associated with delayed CTT, while having IMO only was associated with both delayed CTT and SBTT, but neither with pH. Future investigation is needed to elucidate whether changes in intestinal microbiota affect gut transit.

Small intestinal bacterial overgrowth (SIBO) is characterized by an increase in the bacterial population of the small intestine due to an imbalance between the amount of bacteria and the intestinal barrier. Pediatric SIBO presents with a wide spectrum of symptoms, ranging from mild gastrointestinal complaints to malabsorption or malnutrition. Breath tests are commonly used as noninvasive diagnostic tools for SIBO, but a standardized methodology is currently unavailable. Intestinal flora produces methane which slows intestinal transit and increases the contractile activity of small intestine. Emerging literature suggests a correlation between overgrowth of methanogenic bacteria in the intestines and constipation. Treatment of SIBO involves administration of antibacterial therapy in addition to management of underlying conditions and optimal dietary adjustments. However, research on antibiotic treatment for pediatric patients with constipation and SIBO is limited and has yielded conflicting results. In the current review, we summarize the state-of-the-art of the field and discuss previous treatment attempts and currently used regimens for SIBO patients with constipation, with a focus on pediatric populations.

Chronic intestinal pseudo-obstruction (CIPO) is a rare intractable disease with limited treatment options. Small intestinal bacterial overgrowth (SIBO) often co-occurs with several diseases, including CIPO. While rifaximin (RFX) is effective in treating SIBO, its efficacy for CIPO remains unclear. Here, we aimed to investigate the efficacy and safety of RFX in adult patients with CIPO. Twelve patients were randomly assigned to receive RFX (400 mg three times daily, n=8) or a placebo (PBO, n=4) for 4 weeks. The global symptom score for abdominal bloating (GSS-bloating) and an original whole gastrointestinal symptoms score (O-WGSS) were collected, and a glucose hydrogen breath test (GHBT) and abdominal computed tomography (CT) were performed. No significant differences were observed in the primary endpoint. GSS-bloating improved by 75% and 25% in the PBO and RFX groups, respectively, and O-WGSS improved by 25% in both groups. No significant differences were observed in secondary and other endpoints, including the SIBO eradication rate in the GHBT and small intestinal volume on CT. In a post hoc analysis of SIBO-positive patients with CIPO (4/4 and 4/8 in the PBO and RFX groups), SIBO was eradicated in 25% and 75% of the patients (PBO and RFX groups, respectively) at the end of treatment, indicating a high eradication rate in the RFX group. Furthermore, the small intestinal gas volume decreased in the RFX group, and no severe adverse events occurred. Although no significant improvements were observed in subjective indicators, RFX may be beneficial in alleviating SIBO and reducing the small intestinal gas volume in SIBO-positive patients with CIPO.

Chronic diarrhea, including diarrhea-predominant irritable bowel syndrome (IBS-D), osmotic diarrhea, bile acid diarrhea, and antibiotic-associated diarrhea, is a common problem which is highly associated with disorders of the gut microbiota composition such as small intestinal bacterial overgrowth (SIBO) and so on. A growing number of studies have supported the view that Chinese herbal formula alleviates the symptoms of diarrhea by modulating the fecal microbiota. Chinese herbal polysaccharides (CHPs) are natural polymers composed of monosaccharides that are widely found in Chinese herbs and function as important active ingredients. Commensal gut microbiota has an extensive capacity to utilize CHPs and play a vital role in degrading polysaccharides into short-chain fatty acids (SCFAs). Many CHPs, as prebiotics, have an antidiarrheal role to promote the growth of beneficial bacteria and inhibit the colonization of pathogenic bacteria. This review systematically summarizes the relationship among gut microbiota, chronic diarrhea, and CHPs as well as recent progress on the impacts of CHPs on the gut microbiota and recent advances on the possible role of CHPs in chronic diarrhea.

Dysbiosis of the gut microbiota is associated with the pathogenesis of intestinal diseases such as inflammatory bowel disease, irritable bowel syndrome (IBS), small intestinal bacterial overgrowth (SIBO), and metabolic disease states such as allergies, cardiovascular diseases, obesity, and diabetes. SIBO is a condition characterized by an increased number (>1 × 103 CFU) of abnormal bacterial species in the small intestine. Interest in SIBO has gained importance due to increased awareness of the human microbiome and its potential relationships with human health and disease, which has encouraged new work in this area. In recent years, standard antibiotic regimens (rifaximin and metronidazole) have been used to treat SIBO, but solo antibiotics or their derivatives are insufficient. In this study, the therapeutic effects of the probiotic form, which contains coconut oil and traces of peppermint-lemon-patchouli essential oil, were evaluated on the Dysbiosis-Based Rat SIBO Model. There are significant differences between sick and healthy rats (p = 0.014), between sick rats and rats treated with the oil mix plus probiotic mix protocol (p = 0.026), and between rats treated with only the probiotic and only oil protocols (p = 0.030) in the evaluation of TNF-α levels. Histologically, villi distortion and loss of crypts, epithelial shedding and necrotic changes in the apical regions of the villi, and inflammatory cell infiltrations extending to the lamina propria and submucosa were observed in sick rats. Mitotic figures in villus epithelium and crypts were observed in rats treated with 9.2 × 109 CFU/1000 mg/coconut oil + trace amounts of peppermint-lemon-patchouli essential oil and a probiotic mixture (oil + probiotic mix protocol). A regression of inflammatory reactions and an increase in goblet cells were observed. A decrease was observed in inflammation markers in sick rats. On the other hand, the oil plus probiotic mix protocol recovered digestive system defects in the animals caused by dysbiosis. In the future, these treatment approaches can be effective in the treatment of SIBO.

BACKGROUND: Small intestinal bacterial overgrowth (SIBO) is defined as an excessive growth and/or changed composition of bacteria in the small bowel. Obese patients are at increased risk of SIBO and related complications. The purpose of this study is to evaluate the incidence of SIBO after bariatric bypass procedures, connection between SIBO, symptoms, comorbidities, and liver pathology.
METHODS: Patients underwent a hydrogen breath test with glucose substrate (25 g/200 ml of water). The demographic, anthropometric data, comorbidities, and symptoms were analysed with a questionnaire. In 45 patients, the NAFLD Activity Score was evaluated in liver biopsies.
RESULTS: Glucose breath test was positive in 24/56 (43%) of patients and was associated with higher frequency of defecation (p = 0.022), lactose intolerance (p = 0.047), scleroderma (p = 0.042), irritable bowel syndrome (p = 0.018), and diabetes (p = 0.002). Mean NAFLD Activity Score in SIBO patients (n = 18) was 3.33 and 3.00 in non-SIBO patients (n = 27). In SIBO-positive cohort of patients, a statistically important trend in difference between NAS and difference to range value anti-Xa 4 h after subtherapeutic dose application was calculated.
CONCLUSIONS: The incidence of SIBO after bariatric surgery bypass procedures is alarmingly high (43%). The results of our study conclude that diagnosis cannot be set based on specific symptom and SIBO is related to reduced response to the application of LMWH. Mandatory SIBO screening and appropriate treatment would affect the clinical outcome of the underlying disease, improve it significantly, and prevent the development of its complications.

UNASSIGNED: Crohn\'s disease (CD) is an irreversible inflammatory disorder, characterized by alternating periods of relapse and remission. It is particularly important to predict clinical relapses in patients with CD because patients in remission could relapse frequently in a randomized way. Small intestinal bacterial overgrowth (SIBO) is a symptom of gut microbial dysbiosis and is commonly observed in patients with CD, which may affect disease course. The present research was carried out to establish whether SIBO is linked to the subsequent clinical relapse of CD.
UNASSIGNED: This retrospective observational cohort research included consecutive patients (≥18 years) with quiescent CD who underwent lactulose hydrogen-methane breath test to diagnose SIBO managed at Jinling Hospital in China from January 2016 to June 2020. We assessed demographic data, laboratory parameters, SIBO and clinical characteristics including disease location and behavior, surgical history and current and previous medication at baseline and analyzed these data to identify factors associated with clinical relapse. Patients were followed up for 18 months and assessed for the Crohn\'s Disease Activity Index (CDAI) scores, treatment escalation, and disease progression to determine the primary endpoint of clinical relapse.
UNASSIGNED: Of the 73 enrolled patients, 34 (46.6%) were positive for SIBO. Twenty-seven (37.0%) patients experienced clinical relapse within 18 months (median time of relapse: 13.9 months). SIBO in the relapse group was considerably elevated compared to the non-relapse group (63.0% vs. 37.0%, P=0.032). The multivariate Cox regression analysis showed that SIBO [hazard ratio (HR) 2.79, P=0.017] and penetrating disease behavior (HR 3.66, P=0.040) were the sole individual risk elements for relapse in patients with quiescent CD.
UNASSIGNED: This study indicated that SIBO was highly prevalent in patients with CD, and was independently linked to clinical relapse in quiescent patients. Detecting SIBO may be a valuable option for the prognostic assessment of patients in clinical remission.

Functional abdominal bloating and distension (FABD) are common and frequent symptoms in patients with pre-existing gastrointestinal (GI) disorders. FABD is characterized by recurrent abdominal fullness and bloating. The pathophysiology of FABD is still unclear. However, the plausible mechanisms involved are small intestinal bacterial overgrowth (SIBO), imbalance of gut microbiota, visceral hypersensitivity, intestinal permeability alteration, and disruption of intestinal barrier function. Thus, the creation of a barrier on the wall of the intestine could represent an alternative therapeutic strategy to prevent FABD. This study aimed to investigate the effect of two natural substances, Xyloglucan (XG) and Pea-protein (PP), known for their mucosal-protective properties, in an in vivo model of Partial restraint-stress (PRS). Our results showed that the pre-treatment with a product containing XG and PP in stressed-rats was able to reduce the number of abdominal contractions and visceral hypersensitivity. Moreover, XG and PP were able to reduce intestinal permeability alteration, restoring tight-junctions (TJs) expression and decreased the lactulose-mannitol ratio, a quantitative marker used to measure intestinal permeability, compared to PRS-group. In conclusion, the data obtained revealed that the product containing XG and PP was able to restore the normal intestinal-barrier function; therefore, it could be considered a therapeutic strategy to manage FABD.

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.

BACKGROUND: Prior to antireflux surgery, most patients with symptoms of gastroesophageal reflux disease (GERD) have been taking long-term proton pump inhibitors (PPIs). PPIs have been shown to cause changes to the intestinal microbiota, such as small intestinal bacterial overgrowth (SIBO), which is characterised by symptoms of gas bloating. Patients undergoing antireflux surgery are not routinely screened for SIBO, yet many patients experience gas-related symptoms postoperatively.
METHODS: Data from consecutive patients (n = 104) referred to a speciality reflux centre were retrospectively assessed. Patients underwent a routine diagnostic workup for GERD including history, endoscopy, oesophageal manometry and 24-h pH-impedance monitoring off PPIs. Intestinal dysbiosis was determined by hydrogen and methane breath testing with a hydrogen-positive result indicative of SIBO and a methane-positive result indicative of intestinal methanogen overgrowth (IMO).
RESULTS: 60.6% of patients had intestinal dysbiosis (39.4% had SIBO and 35.6% had IMO). Patients with dysbiosis were more likely to report bloating (74.6% vs 48.8%; P = 0.01) and belching (60.3% vs 34.1%; P = 0.01). The oesophageal acid exposure time and number of reflux episodes were similar between dysbiosis and non-dysbiosis groups, but patients with dysbiosis were more likely to have a positive reflux-symptom association (76.2% vs 31.7%; P < 0.001), especially for regurgitation in those with SIBO (P = 0.01). Hydrogen gas production was significantly greater in patients with a positive reflux-symptom association for regurgitation (228.8 ppm vs 129.1 ppm, P = 0.004) and belching (mean AUC 214.8 ppm vs 135.9 ppm, P = 0.02).
CONCLUSIONS: The prevalence of intestinal dysbiosis is high in patients with GERD, and these patients are more likely to report gas-related symptoms prior to antireflux surgery. Independently, SIBO may be a contributory factor to refractory reflux symptoms and gas bloating in antireflux surgery candidates.