Personality, Anxiety, and Stress in Patients with Small Intestine Bacterial Overgrowth Syndrome. The Polish Preliminary Study.

OBJECTIVE: Small intestinal bacterial overgrowth (SIBO) syndrome is associated with depression and anxiety. This study aimed to examine for the first time the correlation between personality traits, situational anxiety, and stress in Polish patients with SIBO. METHODOLOGY: This study included 26 patients with SIBO aged 20-35 years and 24 non-SIBO patients aged 20-35 years. The following instruments were used: NEO-FFI Personality Inventory, KPS Sense of Stress Questionnaire, and the anxiety-state subscale from the State-Trait Anxiety Inventory (STAI). RESULTS: Compared to the non-SIBO subgroup, SIBO patients expressed specific patterns of personality traits: higher neuroticism, lower extroversion, and a higher state of anxiety and stress. Unlike the non-SIBO subgroup, stress (total emotional tension, external, and intrapsychic) correlated negatively only with extroversion. CONCLUSIONS: Personality is the primary regulator of experience and behavior. The specificity captured in the research is a premise for an in-depth study considering various psychological variables to determine cause-effect relationships.

Small Intestinal Bacterial Overgrowth as Potential Therapeutic Target in Parkinson's Disease.

Increasing evidence suggests that the gut microbiota and the brain are closely connected via the so-called gut-brain axis. Small intestinal bacterial overgrowth (SIBO) is a gut dysbiosis in which the small intestine is abundantly colonized by bacteria that are typically found in the colon. Though not a disease, it may result in intestinal symptoms caused by the accumulation of microbial gases in the intestine. Intestinal inflammation, malabsorption and vitamin imbalances may also develop. SIBO can be eradicated by one or several courses of antibiotics but reappears if the predisposing condition persists. Parkinson's disease (PD) is a common neurodegenerative proteinopathy for which disease modifying interventions are not available. Sporadic forms may start in the gut years before the development of clinical features. Increased gastrointestinal transit time is present in most people with PD early during the course of the disease, predisposing to gut dysbiosis, including SIBO. The role that gut dysbiosis may play in the etiopathogenesis of PD is not fully understood yet. Here, we discuss the possibility that SIBO could contribute to the progression of PD, by promoting or preventing neurodegeneration, thus being a potential target for treatments aiming at slowing down the progression of PD. The direct symptomatic impact of SIBO and its impact on symptomatic medication are also briefly discussed.

[The role of intraepithelial lymphocytes in pathogenesis of small intestinal bacterial overgrowth syndrome]. / Rola limfocytów sródnablonkowych w patogenezie zespolu przerostu bakteryjnego jelita cienkiego.

Small intestinal bacterial overgrowth (SIBO) is a frequent cause of chronic abdominal complaints. So far, a lot information has been gathered on its pathogenesis but are still doubts that raise question why its causes chronic diarrhea in some and constipation in other patients. AIM: The aim of the study was to assess the number of endothelial lymphocytes (IELs) in the duodenal and ileum mucosa in patients with SIBO with dominant diarrhea (SIBO-D) and dominant constipation (SIBO-C). MATERIALS AND METHODS: The study was performed in 30 healthy patients (group I) and 40 patients with SIBO and diarrhoea (group II), and in 4o patients with constipation (group III). To diagnose SIBO the lactulose hydrogen breath test (LHBT) was performed. To determine the number of intraepithelial lymphocytes in duodenal and jejunal mucosa the histological assessment was performed using haematoxylin-eosin staining. Moreover, immunochistochemical method was used to assess the number of enterochromatoffin cells (EC, chromogranin A - LK-2H10) in these some parts of the gut. RESULTS: The results of LHBT were similar in group II and III - 75,6±18,1 ppm and 66,9±16,2 ppm(p>0,05). The number of IELs in duodenal mucosa in controls was 14,6±4,1/100 EN, in group II - 28,3±6,8/100 EN (p<0.01), and in group III - 23,0±9,9/100 EN (p<0,05), and similar differences were in jejunal mucosa. The number of EC in both parts of the gut was higher in SIBO compared to controls. Furthermore, in patients with SIBO-D the number of IELs in duodenum, as well as in jejunum, was positively correlated with the number of EC cells ( p<0,05, p=0,056, respectively). CONCLUSIONS: In patients with SIBO, particularly with SIBO-D, increased number of IELs I EC cells may be a cause of diverse abdominal symptoms.

High Prevalence of Small Intestinal Bacterial Overgrowth among Functional Dyspepsia Patients.

BACKGROUND: Small intestinal bacterial overgrowth (SIBO), characterized by either increased numbers or presence of colonic type bacteria in the small bowel has been previously described in functional dyspepsia (FD), based on breath testing. In this study, we aim to examine the prevalence of SIBO among FD patients using small bowel aspirate culture. METHODS: We prospectively enrolled outpatients fulfilling Rome IV criteria for FD. Severity of symptoms was graded using the patient assessment of upper gastrointestinal symptom severity index (PAGI-SYM) questionnaire. Patients underwent upper gastrointestinal endoscopy and duodenal fluid was aspirated in sterile traps. SIBO was defined as ≥103 colony forming units/mL of duodenal aspirate and/or presence of colonic type bacteria. Patients undergoing gastroscopy due to gastroesophageal reflux symptoms - control group (CG) - and patients with irritable bowel syndrome (IBS) fulfilling Rome IV criteria were also recruited. RESULTS: We enrolled 227 FD subjects, 30 CG, and 90 IBS patients. Among FD patients, 144 (63.4%), 64 (28.2%), and 19 (8.4%) had postprandial distress syndrome (PDS), epigastric pain syndrome (EPS), and overlapping PDS-EPS syndrome, respectively. SIBO prevalence was 20.8%, 12.5%, and 31.6% among PDS, EPS, and overlapping PDS-EPS FD subtypes, respectively. Overall, SIBO prevalence was significantly higher in FD (44/227 [19.4%]) compared to CG (1/30 [3.3%]) (p = 0.037) and similar to IBS (44/227 [19.4%] vs. 15/90 [16.7%], p = 0.63) subjects. SIBO presence was associated neither with total nor with any subscale score of the PAGI-SYM questionnaire. CONCLUSION: In a cohort of Greek FD patients, SIBO prevalence was similar to that of IBS subjects and higher compared to that of controls.

The overlap between irritable bowel syndrome and organic gastrointestinal diseases.

Irritable bowel syndrome (IBS) is a common functional bowel disorder characterised by symptoms of recurrent abdominal pain associated with a change in bowel habit. This condition is one of the most frequent reasons to seek a gastroenterology consultation in primary and secondary care. The diagnosis of IBS is made by identifying characteristic symptoms, as defined by the Rome criteria, and excluding organic gastrointestinal diseases that might otherwise explain these symptoms. Organic conditions that can be mistaken for IBS include coeliac disease, inflammatory bowel disease (IBD), colorectal cancer, and, in those with diarrhoea-predominant symptoms, chronic gastrointestinal infections, microscopic colitis, and primary bile acid diarrhoea. The concept of small intestinal bacterial overgrowth being associated with IBS is shrouded with controversy and uncertainty, mainly because of invalid tests due to poor sensitivity and specificity, potentially leading to incorrect assumptions. There is insufficient evidence to link IBS-type symptoms with exocrine pancreatic insufficiency or with symptomatic uncomplicated diverticular disease, since both are hampered by conflicting data. Finally, there is growing appreciation that IBS can present in patients with known but stable organic gastrointestinal diseases, such as quiescent IBD or coeliac disease. Recognising functional gut symptoms in these individuals is paramount so that potentially harmful escalations in immunosuppressive therapy can be avoided and attention can be focused on addressing disorders of gut-brain interaction. This Review endeavours to aid clinicians who practise adult gastroenterology in recognising the potential overlap between IBS and organic gastrointestinal diseases and highlights areas in need of further research and clarity.

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

BACKGROUND: Gut microbiota alterations including small intestinal bacterial overgrowth (SIBO) might play a role in pathogenesis of irritable bowel syndrome (IBS). Rifaximin could effectively and safely improve IBS symptoms. The aim of this study was to investigate the effect of rifaximin on Gastrointestinal (GI) symptoms, quality of life (QOL) and SIBO eradication in Chinese IBS-D patients. METHODS: This study included 78 IBS-D patients defined by the Rome IV criteria. Patients received 400 mg rifaximin twice daily for 2 weeks and 10-week follow-up. GI symptoms were assessed at week 0, 2, 4, 8 and 12. QOL and lactulose hydrogen breath test (LHBT) results were estimated at week 0 and 4. RESULTS: All participants showed significant improvements in GI symptom subdomains after rifaximin treatment (all P < 0.05), which could maintain at least 10 weeks of follow-up. Additionally, QOL scores were increased with concomitant improvement of clinical symptoms (all P < 0.05). The 45 rifaximin-responsive patients (57.7%) achieved significantly greater GI-symptom improvement than non-responders (all P < 0.05). No GI symptoms were associated with SIBO (all P > 0.05). SIBO normalization after rifaximin treatment measured by LHBT was found in 44.4% (20/45) of patients with SIBO before treatment. CONCLUSION: A short course (2 weeks) of rifaximin improved GI symptoms and QOL in Chinese IBS-D patients whether they had SIBO or not. However, the efficacy of rifaximin could not be explained by the successful eradication of SIBO. Further studies on the therapeutic mechanisms of rifaximin in IBS are urgently needed.

The Effect of Ursodeoxycholic Acid on Small Intestinal Bacterial Overgrowth in Patients with Functional Dyspepsia: A Pilot Randomized Controlled Trial.

Functional dyspepsia (FD) is associated with small intestinal bacterial overgrowth (SIBO). Several animal studies have reported that ursodeoxycholic acid (UDCA) has antibacterial and anti-inflammatory effects in the intestine. We hypothesized that UDCA may be effective against dyspeptic symptoms and SIBO in patients with FD. We conducted this randomized controlled trial to investigate the effects of UDCA in FD patients with SIBO. Twenty-four patients diagnosed with FD and SIBO based on lactulose breath test (LBT) were randomly assigned to either a UDCA treatment group or an untreated group. The treatment group received 100 mg of UDCA three times per day for two months; the untreated group was monitored for two months without intervention. After two months in both groups, we reevaluated LBT and FD symptoms using the Nepean dyspepsia index-K. FD symptoms in the UDCA-treated group were significantly reduced after two months compared with baseline and FD symptom scores between the UDCA-treated and untreated groups showed statistically significant differences after two months. In addition, the total methane gas levels for 90 minutes in LBT were significantly decreased after two months compared with baseline in the UDCA-treated group. In this preliminary exploratory study, we found that two months of UDCA treatment resulted in FD symptom improvement and reduced methane values during 90 minutes on the LBT, suggesting that methane-producing SIBO were associated with symptoms of dyspepsia and that UDCA was helpful in these patients. These findings need to be validated via large-scale controlled and well-designed studies.

Relationship between Small Intestinal Bacterial Overgrowth and Peripheral Blood ET, TLR2 and TLR4 in Ulcerative Colitis.

OBJECTIVE: To investigate the relationship between small intestinal bacterial overgrowth (SIBO) and Endotoxin (ET) concentration in peripheral blood, and levels of toll-like receptors (TLR) 2 and TLR4 expression on surface of peripheral blood mononuclear cells (PBMCs) in patients with ulcerative colitis. STUDY DESIGN: An experimental study. PLACE AND DURATION OF STUDY: The First Hospital of Hebei Medical University, from July 2018 to October 2019. METHODOLOGY: The 130 patients with ulcerative colitis were included in case group. Another 72 healthy cases were selected as control group. SIBO, ET, TLR2, and TLR4, were determined, and compared. RESULTS: Positive rate of SIBO in case group was higher than that in control group (p <0.001). Lactulose hydrogen breath test (LHBT) intestine set value, peripheral blood ET concentration, and TLR2 and TLR4 expression levels on surface of PBMCs in case group were higher than those in control group (all p <0.001); the above indexes in SIBO-positive patients in case group were higher than those in SIBO-negative patients in case group (all p <0.001). Pearson's correlation analysis showed that LHBT intestine set value of SIBO-positive patients in case group was positively correlated with ET concentration, and TLR2 and TLR4 expression levels on surface of PBMCs (r= 0.910, p <0.001; r = 0.970, p <0.001; and r = 0.965, p <0.001 respectively). ET concentration of SIBO-positive patients in case group was positively correlated with expression levels of TLR2 and TLR4 on surface of PBMCs (r=0.962, p <0.001; and r = 0.829 p <0.001 respectively). CONCLUSION: Patients with ulcerative colitis are easy to occur SIBO, and SIBO increases blood endotoxin, TLR2 and TLR4 levels. Synergistic effects of endotoxin and endotoxin receptors TLR2 and TLR4 overexpression mediate body inflammation and may be involved in progression of ulcerative colitis. Patients with ulcerative colitis with excessive growth of small intestinal bacteria are more likely to have hypertoxemia.

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.

Total Bilirubin Is Associated with Small Intestinal Bacterial Overgrowth in Diarrhea Predominant Irritable Bowel Syndrome.

BACKGROUND: Small intestinal bacterial overgrowth (SIBO) associated with irritable bowel syndrome (IBS) can cause microscopic mucosal inflammation and oxidative damage. Bilirubin is a marker of oxidant stress that is responsible for anti-oxidative activities. The objective of this research was to determine whether or not total bilirubin is associated with SIBO according to IBS subtypes. MATERIALS AND METHODS: We retrospectively reviewed the charts of patients who showed IBS symptoms with documented results of lactulose breath test for SIBO. Multivariate models were used in order to assess the relationship of total bilirubin with SIBO according to IBS subtypes. In addition, we observed changes in total bilirubin when SIBO was treated with rifaximin in the relevant IBS subtype. RESULTS: The total bilirubin level of subjects with SIBO was significantly higher than it was in those without. An examination according to IBS subtype groups showed that total bilirubin was independently associated with SIBO only in the subjects with diarrhea-predominant IBS subtype (OR: 2.723, 95% CI: [1.303-5.692], p<0.001). Additionally, a decrease in total bilirubin level and overall improvement of abdominal symptoms were observed following rifaximin treatment. CONCLUSIONS: These findings suggest that total bilirubin levels may provide additional information regarding the presence of SIBO in diarrhea-predominant IBS patients.

Blind Pouch Syndrome-associated Anastomotic Ulcer Diagnosed with Capsule and Double-balloon Endoscopy.

Blind pouch syndrome-associated anastomotic ulcer is rare, and its endoscopic features remain poorly described. A 79-year-old man was referred to our hospital for melena. Capsule endoscopy revealed multiple ulcers in the small intestine. Double-balloon endoscopy (DBE) and a gastrografin examination through DBE revealed a potential anastomotic ulcer, a blind pouch, and a side-to-side anastomosis in the middle of the small intestine. Laparoscopic partial resection of the small intestine with anastomosis was performed on the suspected blind pouch syndrome-associated anastomotic ulcer. To our knowledge, this is the first report describing the endoscopic features of a blind pouch syndrome-associated anastomotic ulcer.

The chronic intestinal pseudo-obstruction subtype has prognostic significance in patients with severe gastrointestinal dysmotility related intestinal failure.

BACKGROUND & AIMS: Severe gastrointestinal dysmotility (GID) is a significant cause of chronic intestinal failure (CIF) with unclear benefits of sub-classifying into Chronic Intestinal Pseudo-obstruction (CIPO) and non-CIPO sub-types. We compared outcomes between CIPO and non-CIPO sub-types in a tertiary cohort of patients with CIF resulting from severe GID. METHODS: Adults with primary GID, commenced on home parenteral nutrition (HPN) over a 16-year period at a national referral centre, were included. All patients satisfied GID clinical criteria which mandated evidence of small bowel involvement either objectively (abnormal antroduodenal manometry) or pragmatically (failure to progress on small bowel feeding). Clinical outcomes including HPN dependency and survival were compared between CIPO and non-CIPO sub-types. RESULTS: Patients with primary GID requiring HPN (n = 45, age 38 ± 2, 33 females, 23/45 (51%) CIPO, 22/45 (49%) non-CIPO) were included. Patients with CIPO had more surgical interventions (P = 0.03), higher incidence of bacterial overgrowth (P = 0.006), greater parenteral energy (P = 0.02) and volume requirements (P = 0.05). Overall, during a mean 6 years' follow-up, 36/45 (80%) patients remained HPN dependent. Multivariate analyses confirmed that the non-CIPO sub-type (P = 0.04) and catheter related blood stream infections/1000 days (P = 0.01) were predictive factors for time to discontinuing HPN. Overall 5-year survival on HPN was 85%, with no difference between sub-types (P = 0.83). CONCLUSIONS: The CIPO sub-type is associated with higher HPN dependency and should be recognized as a separate entity in severe GID. In multidisciplinary settings with continuous close monitoring of risks and benefits, our data confirm HPN is a safe, life-preserving therapy in severe GID related CIF.

Fecal microbiota analysis of children with small intestinal bacterial overgrowth among residents of an urban slum in Brazil / Análise da microbiota fecal de crianças com sobrecrescimento bacteriano no intestino delgado de moradoras de uma favela urbana no Brasil

Abstract Objective: To analyze the fecal microbiota composition of children living in an urban slum in Brazil, with or without small intestinal bacterial overgrowth, and to investigate the occurrence of stunting and anemia. Methods: A total of 100 children were studied, aged 5-11 years, from the municipality of Osasco, São Paulo. Small intestinal bacterial overgrowth was screened through hydrogen and methane breath test with lactulose. Weight and height were measured, and the height-for-age and body mass-for-age anthropometric indexes were calculated. The occurrence of anemia was investigated by capillary hemoglobin. Analysis of bacterial phylum, genus, and species was performed by real-time polymerase chain reaction in fecal samples. Results: Small intestinal bacterial overgrowth was identified in 61.0% of the children. A lower mean of height-for-age Z-score ([−0.48 ± 0.90] vs. [−0.11 ± 0.97]; p = 0.027), as well as capillary hemoglobin ([12.61 ± 1.03 g/dL] vs. [13.44 ± 1.19 g/dL]; p < 0.001) was demonstrated in children with SIBO when compared with children without small intestinal bacterial overgrowth. Children with small intestinal bacterial overgrowth presented a higher frequency of Salmonella spp., when compared to those without small intestinal bacterial overgrowth (37.7% vs. 10.3%; p = 0.002). Higher counts of total Eubacteria (p = 0.014) and Firmicutes (p = 0.038) were observed in children without small intestinal bacterial overgrowth; however, a higher count of Salmonella (p = 0.002) was found in children with small intestinal bacterial overgrowth. Conclusion: Children who lived in a slum and were diagnosed with small intestinal bacterial overgrowth showed lower H/A Z-scores and hemoglobin levels. Furthermore, differences were observed in the fecal microbiota of children with small intestinal bacterial overgrowth, when compared to those without it; specifically, a higher frequency and count of Salmonella, and lower counts of Firmicutes and total Eubacteria.

Resumo Objetivo: Analisar a composição da microbiota fecal de crianças moradoras de uma favela urbana no Brasil, com e sem sobrecrescimento bacteriano no intestino delgado, e investigar a ocorrência de déficit de crescimento e anemia. Métodos: Foram estudadas 100 crianças, com idade entre 5 e 11 anos, na cidade de Osasco, São Paulo. Sobrecrescimento bacteriano no intestino delgado foi pesquisado por teste respiratório do hidrogênio e metano no ar expirado com lactulose. Foram mensurados peso, estatura e calculados os índices antropométricos estatura para idade e índice de massa corporal para idade. Foi investigada a ocorrência de anemia, pela avaliação da hemoglobina capilar. A análise dos filos, gêneros e espécies bacterianas em amostras de fezes foi realizada por polymerase chain reaction em tempo real. Resultados: Sobrecrescimento bacteriano no intestino delgado foi diagnosticado em 61,0% das crianças avaliadas. Foi verificada menor média do escore Z do índice estatura para idade (-0,48±0,90 vs.-0,11±0,97 DP) e de hemoglobina capilar (12,61±1,03 vs. 13,44±1,19 g/dL) no grupo de crianças com sobrecrescimento bacteriano no intestino delgado, quando comparadas àquelas sem sobrecrescimento bacteriano no intestino delgado (p < 0,05). Nas crianças com sobrecrescimento bacteriano no intestino delgado foi observada maior frequência de Salmonella spp., quando comparadas àquelas sem sobrecrescimento bacteriano no intestino delgado (37,7% vs. 10,3%; p = 0,002). Maior contagem de Eubactérias totais (p = 0,014) e Firmicutes (p = 0,038) foi observada nas crianças sem sobrecrescimento bacteriano no intestino delgado, enquanto que as crianças com sobrecrescimento bacteriano no intestino delgado apresentaram maior contagem de Salmonella (p = 0,002). Conclusão: Nas crianças com diagnóstico de sobrecrescimento bacteriano no intestino delgado verificaram-se menores valores de estatura para idade e de hemoglobina. Foram constatadas diferenças na microbiota fecal das crianças com sobrecrescimento bacteriano no intestino delgado, especificamente, maior frequência e contagem de Salmonella spp. e menores contagens de Firmicutes e Eubactérias totais.

Small Intestinal Bacterial Overgrowth: Nutritional Implications, Diagnosis, and Management.

Small intestinal bacterial overgrowth (SIBO), characterized by the presence of excessive bacteria in the small intestine, is typically described as a malabsorptive syndrome occurring in the context of gut stasis syndromes. SIBO is now considered to be a disorder associated with diverse clinical conditions without classic risk factors for SIBO and a cause of several nonspecific gastrointestinal and nongastrointestinal symptoms. Because there is currently no gold standard for diagnosing SIBO, its prevalence and role in the pathogenesis of other diseases remain uncertain; as does optimal treatment of patients with relapsing symptoms.

The gut-liver axis: impact of a mouse model of small-bowel bacterial overgrowth.

BACKGROUND: The mechanisms by which intestinal bacteria impact liver diseases remain poorly understood. The aim of this study was to develop a mouse model of small-bowel bacterial overgrowth and to determine its impact on hepatobiliary injury. MATERIALS AND METHODS: A jejunal self-filling blind loop (SFBL) was created in C57BL/6 mice. Three weeks after surgery, the mice were euthanized, and bacterial cultures of luminal content of the loop and extraintestinal tissues were performed. Liver and jejunum were collected for histological grading of inflammation and injury. Serum liver biochemistry assays were performed. Hepatobiliary transporter mRNA expression in liver was measured by quantitative real-time polymerase chain reaction. Bile and blood were collected for measurement of total bile acids, phospholipid, and cholesterol. Mice undergoing jejunal transection and reanastomosis and laparotomy only served as control groups. RESULTS: SFBL induced a dramatic increase in intraluminal bacterial counts, mesenteric lymph node bacterial translocation, and evidence of jejunal and hepatobiliary injury. Significant reductions in hepatic expression of hepatobiliary transporters involved in biliary canalicular export and basolateral uptake were observed in SFBL mice. SFBL resulted in a significant increase in biliary total bile acid concentration, decreases in bile phospholipid and cholesterol output, and an increase in the bile acid/phospholipid ratio. CONCLUSIONS: We have developed a reproducible mouse model of small-bowel bacterial overgrowth with evidence of liver inflammation, altered hepatobiliary transporter expression, and alterations in bile composition. This model may help to elucidate the mechanisms by which gut-derived bacterial factors impact the liver and contribute to the exacerbation of liver diseases and biliary injury.

Liver disease symptoms in non-alcoholic fatty liver disease and small intestinal bacterial overgrowth.

INTRODUCTION: It seems that there is a relationship between small intestinal bacterial overgrowth (SIBO) and non-alcoholic fatty liver disease (NAFLD). The main objective of this study was to evaluate the prevalence of SIBO among NAFLD patients. METHODS: In this descriptive-analytical cross-sectional study, 98 eligible NAFLD patients were evaluated for SIBO using hydrogen breath test (HBT). They were divided into SIBO-positive and SIBO-negative groups. Demographic, clinical, and laboratory data were obtained. RESULTS: Based on the HBT, 38 patients (39%) had bacteria overgrowth. There were no significant differences between SIBO-positive and SIBO-negative regarding demographic data and BMI classification (P > 0.05). Biochemical variables, the results of abdominal ultrasound, and liver elastography did not show any significant difference between SIBO-positive and SIBO-negative patients (P > 0.05). Patients with SIBO were found to have higher rates of bloating, while abdominal pain was more prevalent in SIBO-negative patients (P < 0.001). CONCLUSIONS: SIBO is prevalent in NAFLD and associated with bloating in these patients. Further studies are necessary to elucidate if therapeutic manipulation of gut microbiota reduces the risk of NAFLD, fibrosis, and liver cirrhosis.