A systematic review and meta-analysis on the prevalence of non-malignant, organic gastrointestinal disorders misdiagnosed as irritable bowel syndrome.

Treatable gastrointestinal disorders in patients with symptoms typical for irritable bowel syndrome (IBS) may be overlooked. The prevalence of five gastrointestinal conditions-bile acid diarrhoea (BAD), carbohydrate malabsorption (CM), microscopic colitis (MC), pancreatic exocrine insufficiency (PEI) and small intestinal bacterial overgrowth (SIBO) was systematically assessed from studies including consecutive patients meeting diagnostic criteria for IBS. 4 databases were searched from 1978 to 2020. Studies were included if they evaluated the prevalence of these conditions in secondary healthcare setting. Estimated pooled rates were calculated and statistical heterogeneity between studies was evaluated using Q and I2 statistics. Seven studies (n = 597) estimated the pooled prevalence for BAD as 41% (95% CI 29-54). 17 studies (n = 5068) estimated that of MC as 3% (95% CI 2-4%). Two studies (n = 478) suggested a rate of 4.6% (range: 1.8-6.1%) for PEI. Using breath testing, 26 studies (n = 6700) and 13 studies (n = 3415) estimated the prevalence of lactose and fructose malabsorption as 54% (95% CI 44-64%) and 43% (95% CI 23-62%); 36 studies (n = 4630) and 22 studies (n = 2149) estimated that of SIBO as 49% (95% CI 40-57%) with lactulose and 19% (95% CI 13-27%) with glucose. Rates of all conditions were significantly higher than in healthy controls. A significant proportion of patients presenting to secondary care with IBS have an organic condition which may account for their symptoms. Failure to exclude such conditions will deny patients effective treatment.

Effects of Proton Pump Inhibitors on the Small Bowel and Stool Microbiomes.

BACKGROUND: Proton pump inhibitor (PPI) use is extremely common. PPIs have been suggested to affect the gut microbiome, and increase risks of Clostridium difficile infection and small intestinal bacterial overgrowth (SIBO). However, existing data are based on stool analyses and PPIs act on the foregut. AIMS: To compare the duodenal and stool microbiomes in PPI and non-PPI users. METHODS: Consecutive subjects presenting for upper endoscopy without colonoscopy were recruited. Current antibiotic users were excluded. Subjects taking PPI were age- and gender-matched 1:2 to non-PPI controls. Subjects completed medical history questionnaires, and duodenal aspirates were collected using a validated protected catheter. A subset also provided stool samples. Duodenal and stool microbiomes were analyzed by 16S rRNA sequencing. RESULTS: The duodenal microbiome exhibited no phylum-level differences between PPI (N = 59) and non-PPI subjects (N = 118), but demonstrated significantly higher relative abundances of families Campylobacteraceae (3.13-fold, FDR P value < 0.01) and Bifidobacteriaceae (2.9-fold, FDR P value < 0.01), and lower relative abundance of Clostridiaceae (88.24-fold, FDR P value < 0.0001), in PPI subjects. SIBO rates were not significantly different between groups, whether defined by culture (> 103 CFU/ml) or 16S sequencing, nor between subjects taking different PPIs. The stool microbiome exhibited significantly higher abundance of family Streptococcaceae (2.14-fold, P = 0.003), and lower Clostridiaceae (2.60-fold, FDR P value = 8.61E-13), in PPI (N = 22) versus non-PPI (N = 47) subjects. CONCLUSIONS: These findings suggest that PPI use is not associated with higher rates of SIBO. Relative abundance of Clostridiaceae was reduced in both the duodenal and stool microbiomes, and Streptococcaceae was increased in stool. The clinical implications of these findings are unknown.

Acute gastric injury after ingestion of substrate with hyperosmolar glucose and benzoate inversely related with small intestinal bacterial overgrowth.

BACKGROUND/AIMS: The occurrence of gastrointestinal symptoms and the presence of small intestinal bacterial overgrowth (SIBO) could be determined after ingestion of substrate with highly concentrated glucose for glucose breath test (GBT), after which endoscopic images for acute gastric injury have not been clarified. The aims of this study were to investigate the prevalence and relationship of acute gastric injury with SIBO after GBT. MATERIALS AND METHODS: A cohort of 235 patients with functional gastrointestinal symptoms undergoing breath test with 50 g glucose solution, immediately followed by upper endoscopy were surveyed. The acute gastric injury in endoscopic images and the GBT for hydrogen (H2) or methane (CH4) were assessed. RESULTS: The prevalence of acute gastric injury was 28.1% (66/235) after GBT. There were significant differences in GBT positivity (+) with and without gastric injury (25.8% vs 40.8%, p=0.03). In subtypes, GBT (H2) + was significantly lower in group with gastric injury than in the group without. No differences were seen in GBT (CH4) + between two groups. On multivariate analysis, the subtype of GBT (H2) + (Odds ratio (OR)=0.42; 95% Confidence interval (CI)=0.20-0.90; p=0.03) inversely and female (OR=2.11; 95% CI=1.11-4.00; p=0.02) were significantly related with gastric injury. Whereas gastric injury was the only independent related factor for GBT + inversely (OR=0.51; 95% CI=0.27-0.97; p=0.04). CONCLUSION: Highly concentrated glucose might provoke acute gastric injury, which could predict the absence of SIBO.

Systematic review with meta-analysis: the prevalence of small intestinal bacterial overgrowth in inflammatory bowel disease.

BACKGROUND: Current data on small intestinal bacterial overgrowth (SIBO) in patients with inflammatory bowel diseases (IBD) are controversial. AIM: To conduct a systematic review and meta-analysis to determine the prevalence of SIBO in patients with ulcerative colitis (UC) and Crohn's disease (CD). METHODS: Electronic databases were searched up to May 2018 for studies reporting prevalence of SIBO in IBD patients. The prevalence rate of SIBO among IBD patients and the odds ratio (OR) and 95% CI of SIBO in IBD patients compared with controls were calculated. RESULTS: The final dataset included 11 studies (1175 adult patients with IBD and 407 controls), all utilising breath test for diagnosis of SIBO. The proportion of SIBO in IBD patients was 22.3% (95% CI 19.92-24.68). The OR for SIBO in IBD patients was 9.51 (95% CI 3.39-26.68) compared to non-IBD controls, and high in both CD (OR = 10.86; 95% CI 2.76-42.69) and UC (OR = 7.96; 95% CI 1.66-38.35). In patients with CD, subgroup analysis showed the presence of fibrostenosing disease (OR = 7.47; 95% CI 2.51-22.20) and prior bowel surgery (OR = 2.38; 95% CI 1.65-3.44), especially resection of the ileocecal valve, increased the odds of SIBO. Individual studies suggest that combined small and large bowel disease but not disease activity may be associated with SIBO. CONCLUSIONS: Overall, there is a substantial increase in the prevalence of SIBO in IBD patients compared to controls. Prior surgery and the presence of fibrostenosing disease are risk factors for SIBO in IBD.

Small-Intestinal Bacterial Overgrowth is Associated With Concurrent Intestinal Inflammation But Not With Systemic Inflammation in Crohn's Disease Patients.

GOALS: We studied the prevalence and predictors of small-intestinal bacterial overgrowth (SIBO) in Crohn's disease (CD) outpatients and the relationship between SIBO and intestinal and/or systemic inflammation. BACKGROUND: The relationship of SIBO with systemic and intestinal inflammation in CD patients is unclear. STUDY: In this cross-sectional study, conducted between June, 2013 and January, 2015, 92 CD patients and 97 controls with nonchronic gastrointestinal complaints were assessed for the presence of SIBO using the H2/CH4 glucose breath test. Multivariate logistic regression 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), and biomarker of intestinal inflammation [fecal calprotectin concentration (FCC)]. RESULTS: The SIBO rate was significantly higher in CD patients than in controls (32.6% vs. 12.4%, respectively, P=0.0008). Patients with and without SIBO were comparable with regard to demographics, systemic inflammatory biomarkers, and disease characteristics, except for the stricturing phenotype being more common in SIBO-positive CD patients (43.3% vs. 19.3%, P=0.015). Notably, FCC was significantly higher in SIBO-positive patients (median of 485.8 vs.132.7 µg/g; P=0.004). Patients presenting increased FCC and stricturing disease had an odds of 9.43 (95% confidence interval, 3.04-11.31; P<0.0001) and 3.83 (95% confidence interval, 1.54-6.75; P=0.025) respectively, for SIBO diagnosis. CONCLUSIONS: In CD patients, SIBO is a highly prevalent condition. Stricturing phenotype and increased FCC were strongly and independently associated with the presence of SIBO. SIBO diagnostic work-up followed by directed treatment is recommended in CD patients who present stricturing disease, especially in those with concurrent intestinal inflammation.

Etiopathogenesis of rosacea: a prospective study with a three-year follow-up.

BACKGROUND: The aim of this study was to investigate the role of Demodex folliculorum (DF), Helicobacter pylori (HP), and small intestine bacterial overgrowth (SIBO) in the development of rosacea. METHODS: A case-control study including 60 patients with rosacea and 40 healthy controls was performed. All the patients underwent standardized skin surface biopsy to investigate DF, urea breath test for HP and lactulose breath test and glucose breath test for SIBO. Etiological therapy was started in the following order: acaricidal treatment, antibiotics for SIBO and HP. These exams were repeated after 3 years. Statistical analysis was performed. RESULTS: As regards the 88 patients who completed the entire follow-up, DF positivity was found in 47.7% of the patients, SIBO in 25.0%, and HP in 21.6%. SIBO significantly prevailed in papulopustular rosacea, while HP in erythrosis. At the 6-month follow up, the 61% of patients were in remission. After 3 years, 18% of patients dropped out, while the remaining patients repeated all the investigations. The majority of patients were still in remission and negative for HP while only 5 were positive for DF and 4 for SIBO. CONCLUSIONS: SIBO was the most relevant factor in papulopustular rosacea. Its treatment was crucial in improvement and in maintaining the clinical remission.

Positive Glucose Breath Tests in Patients with Hysterectomy, Gastrectomy, and Cholecystectomy.

BACKGROUND/AIMS: This study aimed to investigate the prevalence and characteristics of small intestinal bacterial overgrowth (SIBO) in patients undergoing abdominal surgeries, such as gastrectomy, cholecystectomy, and hysterectomy. METHODS: One hundred seventy-one patients with surgery (50 hysterectomy, 14 gastrectomy, and 107 cholecystectomy), 665 patients with functional gastrointestinal disease (FGID) and 30 healthy controls undergoing a hydrogen (H2)-methane (CH4) glucose breath test (GBT) were reviewed. RESULTS: GBT positivity (+) was significantly different among the surgical patients (43.9%), FGID patients (31.9%), and controls (13.3%) (p<0.01). With respect to the patients, 65 (38.0%), four (2.3%), and six (3.5%) surgical patients and 150 (22.6%), 30 (4.5%), and 32 (4.8%) FGID patients were in the GBT (H2)+, (CH4)+ and (mixed)+ groups, respectively (p<0.01). The gastrectomy group had a significantly increased preference in GBT+ (71.4% vs 42.0% or 41.1%, respectively) and GBT (H2)+ (64.3% vs 32.0% or 37.4%, respectively) compared with the hysterectomy or cholecystectomy groups (p<0.01). During GBT, the total H2 was significantly increased in the gastrectomy group compared with the other groups. CONCLUSIONS: SIBO producing H2 is common in abdominal surgical patients. Different features for GBT+ may be a result of the types of abdominal surgery.

Small intestinal bacterial overgrowth in adult patients with type 1 diabetes: its prevalence and relationship with metabolic control and the presence of chronic complications of the disease.

INTRODUCTION Gastrointestinal symptoms may occur in 50% to 70% of patients with diabetes. OBJECTIVES The aim of this study was to evaluate the prevalence of small intestinal bacterial overgrowth (SIBO) in patients with diabetes, as well as the relationship between SIBO and metabolic control of diabetes and the presence of chronic complications of the disease. PATIENTS AND METHODS The study group included 148 patients with type 1 diabetes, treated in the years 2013-2015. The control group consisted of 41 healthy volunteers. The presence of SIBO was assessed with a noninvasive breath test using 20 g of lactulose suspended in 200 ml of water, with the assessment of exhaled hydrogen concentrations. The measurements were performed at 15-minute intervals in the first hour and at 30-minute intervals in the second hour of the test. A positive result was considered as the output value of exhaled hydrogen of 20 parts per million (ppm) or higher or an increase in the output value of the exhaled hydrogen of 12 ppm during the first 60 minutes of the test.  RESULTS We observed a lower prevalence of SIBO in the study group in comparison with controls (56 patients [37.8%] vs 30 healthy volunteers [73%]; P = 0.006). In the logistic regression model, this association was independent of age, sex, body mass index, cigarette smoking, serum C-reactive protein concentrations, and estimated glomerular filtration rate (odds ratio, 0.26; 95% confidence interval, 0.10-0.68; P = 0.006). CONCLUSIONS The prevalence of SIBO in patients with type 1 diabetes is lower than that in healthy subjects. One of the possible causes might be the beneficial effect of nutritional therapy in patients with diabetes.

Prevalence of Small Intestinal Bacterial Overgrowth among Chronic Pancreatitis Patients: A Case-Control Study.

Background. Patients with chronic pancreatitis (CP) exhibit numerous risk factors for the development of small intestinal bacterial overgrowth (SIBO). Objective. To determine the prevalence of SIBO in patients with CP. Methods. Prospective, single-centre case-control study conducted between January and September 2013. Inclusion criteria were age 18 to 75 years and clinical and radiological diagnosis of CP. Exclusion criteria included history of gastric, pancreatic, or intestinal surgery or significant clinical gastroparesis. SIBO was detected using a standard lactulose breath test (LBT). A healthy control group also underwent LBT. Results. Thirty-one patients and 40 controls were included. The patient group was significantly older (53.8 versus 38.7 years; P < 0.01). The proportion of positive LBTs was significantly higher in CP patients (38.7 versus 2.5%: P < 0.01). A trend toward a higher proportion of positive LBTs in women compared with men was observed (66.6 versus 27.3%; P = 0.056). The subgroups with positive and negative LBTs were comparable in demographic and clinical characteristics, use of opiates, pancreatic enzymes replacement therapy (PERT), and severity of symptoms. Conclusion. The prevalence of SIBO detected using LBT was high among patients with CP. There was no association between clinical features and the risk for SIBO.

Small intestinal bacterial overgrowth in patients with chronic pancreatitis.

GOALS: To assess the prevalence of small intestinal bacterial overgrowth (SIBO) in chronic pancreatitis (CP), and analyze factors related with SIBO in CP. BACKGROUND: SIBO is to be considered a factor that worsens symptoms and nutritional status in patients with CP. However, the few studies evaluating the rate of SIBO in CP patients used nonuniform and nonstandardized procedures, and reported a wide range of positivity (0% to 92%). Those studies often investigated CP patients with previous resection surgery (cause of SIBO per se). STUDY: CP patients and controls evaluated for SIBO by the H2 glucose breath test with a standard protocol. For CP patients, the relationship between test results, abdominal symptoms, and clinical and biochemical variables was analyzed. RESULTS: A total of 43 CP patients and 43 controls were enrolled. Of the CP patients, 8 had advanced disease (defined by M-ANNHEIM index) and none had undergone previous surgery. The glucose breath test positivity rate was higher in the CP patients than in the controls (21% vs. 14%), albeit without a significant difference (P=0.57). Mean fasting H2 excretion and mean H2 excretion at 120 minutes also had a trend toward higher levels in CP patients. There were no clinical differences between CP patients with or without SIBO, but there were nutritional differences for lower levels of vitamin D and higher levels of folate in these patients with SIBO. CONCLUSIONS: Our findings suggest that SIBO is not uncommon in uncomplicated CP patients. The lack of a significant difference compared with controls might be due to the study being underpowered. SIBO in CP patients does not seem to be related to peculiar clinical features, but it might affect nutritional status.

[The role of small bowel microflora in the development of secondary lactase deficiency and the possibilities of its treatment with probiotics].

AIM: To estimate the incidence of secondary lactase deficiency (SLD) in patients with postinfectious irritable bowel syndrome (PIBS) and the value of the small bowel microflora in its development and to elaborate treatment options for SLD. SUBJECTS AND METHODS: One hundred and thirty-eight patients with PIBS, including 112 (81.2%) women and 26 (18.8%) men, were examined. The patients' mean age was 33.9 +/- 9.1 years. The duration of the disease was 2.6 +/- 1.4 years. Lactase deficiency (LD) was diagnosed using the color scale to test biopsy specimens from the duodenal retrobulbar region. The bacterial overgrowth syndrome (BOS) was identified by a 2-hour lactulose (20 ml) hydrogen breath test. Sixty patients with moderate SLD were randomized to 2 groups: 1) 41 patients received basic therapy (mesim forte as one tablet t.i.d., no-spa, 40 mg, t.i.d.) and combined probiotic bifiform (Ferrosan) containing Bifidobacterium longum 107, Enterococcus faecium 107 as one capsule t.i.d. for 14 days. Group 2 patients (n = 19) had basic therapy in combination with placebo. RESULTS: SLD was detected in 59.4% of the patients with PIBS, including 43.5 and 15.9% with moderate and severe forms, respectively. In all cases, SLD was accompanied by BOS in the small bowel lumen, as confirmed by the results of a hydrogen breath test [101 +/- 37 ppm (a normal value of < 20 ppm)]. After a 14-day course of therapy with the combined probiotic bifiform, restoration of eubiosis in the small bowel lumen was achieved in 70.8% of the patients, as shown by the lesser degree of BOS (86.9 +/- 40.9 and 17.4 +/- 6.6 ppm before and after treatment, respectively; p < 0.01) and by normalization of the lactase test (p < 0.01). In the comparative placebo group, 68.4% showed no clear positive changes, SLD and BOS remained. CONCLUSION: The changes in the small bowel intraluminal microflora, which developed after prior intestinal infection, played a great role in the development of SLD. Bifiform belongs to the currently available probiotics and may be recommended to correct SLD in patients with PIBS resulting from the impaired microbiota of the small bowel and to prevent BOS.

Chronic prostatitis and small intestinal bacterial overgrowth: effect of rifaximin.

INTRODUCTION: This pilot study determined the efficacy of rifaximin, a gut-directed antibiotic, in reducing chronic prostatitis (CP) and gastrointestinal (GI) symptoms in patients with CP type III. The prevalence of small intestinal bacterial overgrowth (SIBO) and irritable bowel syndrome (IBS) in patients with CP was also evaluated. MATERIALS AND METHODS: Chronic prostatitis patients were recruited and screened for SIBO and IBS using the lactulose breath test (LBT) and Rome II criteria, respectively. Patients with a positive LBT result and Chronic Prostatitis Symptom Index (CPSI) score ≥ 15 received rifaximin 550 mg three times daily for 10 days. The CPSI score and global improvement of CP and GI symptoms were ascertained at screening (ie, 7 days before therapy), at baseline immediately before therapy (ie, day 0), and on days 14 and 28. RESULTS: Fourteen of 16 CP patients (88%) had a positive LBT result and were included in this therapeutic study (mean age, 41 years). Mean CPSI score significantly decreased from screening to day 28 (ie, 18 days after rifaximin treatment; p = 0.043). Mean abdominal pain and bloating scores were also significantly reduced on day 28 versus baseline (p = 0.010 and p = 0.003, respectively). Chronic prostatitis patients with IBS and SIBO had a statistically significant response as well. CONCLUSION: Data from this pilot study suggest that SIBO and IBS are common in CP and that patients with CP and SIBO may benefit from rifaximin therapy. Further studies are warranted.

Small intestinal clustered contractions and bacterial overgrowth: a frequent finding in obese patients.

BACKGROUND: Small intestinal bacterial overgrowth (SIBO) has been observed in several disorders of the gastrointestinal tract. Studies have shown abnormalities of motor function in obese patients, and there is indirect evidence suggesting that SIBO is present in them. AIMS: To study small intestinal motility and the prevalence of SIBO in obese patients and to determine whether there was any relationship between both parameters. METHODS: Thirty-nine patients scheduled for bariatric surgery were subjected to hydrogen breath test with lactulose and to a stationary small intestinal motility study with perfused catheters. RESULTS: SIBO was observed in 41% of obese patients and was not related to body mass index. Small intestinal manometry showed a marked increase of clustered contractions in obese patients with SIBO compared to obese subjects without SIBO, whereas all the other parameters of fasting cyclic activity were not different. CONCLUSIONS: SIBO was a frequent finding in obese patients and was associated with an increased pattern of clustered contractions, which was not observed in absence of SIBO.

Small intestinal bacterial overgrowth syndrome.

Human intestinal microbiota create a complex polymicrobial ecology. This is characterised by its high population density, wide diversity and complexity of interaction. Any dysbalance of this complex intestinal microbiome, both qualitative and quantitative, might have serious health consequence for a macro-organism, including small intestinal bacterial overgrowth syndrome (SIBO). SIBO is defined as an increase in the number and/or alteration in the type of bacteria in the upper gastrointestinal tract. There are several endogenous defence mechanisms for preventing bacterial overgrowth: gastric acid secretion, intestinal motility, intact ileo-caecal valve, immunoglobulins within intestinal secretion and bacteriostatic properties of pancreatic and biliary secretion. Aetiology of SIBO is usually complex, associated with disorders of protective antibacterial mechanisms (e.g. achlorhydria, pancreatic exocrine insufficiency, immunodeficiency syndromes), anatomical abnormalities (e.g. small intestinal obstruction, diverticula, fistulae, surgical blind loop, previous ileo-caecal resections) and/or motility disorders (e.g. scleroderma, autonomic neuropathy in diabetes mellitus, post-radiation enteropathy, small intestinal pseudo-obstruction). In some patients more than one factor may be involved. Symptoms related to SIBO are bloating, diarrhoea, malabsorption, weight loss and malnutrition. The gold standard for diagnosing SIBO is still microbial investigation of jejunal aspirates. Non-invasive hydrogen and methane breath tests are most commonly used for the diagnosis of SIBO using glucose or lactulose. Therapy for SIBO must be complex, addressing all causes, symptoms and complications, and fully individualised. It should include treatment of the underlying disease, nutritional support and cyclical gastro-intestinal selective antibiotics. Prognosis is usually serious, determined mostly by the underlying disease that led to SIBO.

High prevalence of small intestinal bacterial overgrowth in patients with morbid obesity: a contributor to severe hepatic steatosis.

BACKGROUND: With the increasing prevalence of obesity, non-alcoholic fatty liver disease (NAFLD) has become a major cause of liver diseases. Small intestinal bacterial overgrowth (SIBO) could be related to NAFLD. Our aim was to determine the prevalence of SIBO and its relationship with liver lesions in morbidly obese patients. METHODS: A glucose hydrogen (H(2)) breath test (positive if fasting breath H(2) concentration > 20 ppm and/or an increase of > 10 ppm over baseline within the first 2 h) was performed in obese patients referred for bariatric surgery (body mass index [BMI] > 40 kg/m(2) or > 35 in association with comorbidities) and in healthy non-obese subjects. In obese patients, a surgical liver biopsy was performed. RESULTS: One hundred and forty-six patients (129 women, age [mean+/-SE]: 40.7 +/- 11.4 years) were prospectively included in the study. The mean BMI was 46.1+/-6.4 kg/m(2). A liver biopsy was available in 137 patients and a breath test in 136. The frequency of positive breath tests was higher in obese patients (24/136, 17.1%) than in healthy subjects (1/40, 2.5%; P=0.031). In the univariate analysis, SIBO was not associated with clinical variables, but tended to be associated with more frequent severe hepatic steatosis (26.3 vs. 10.3%, P=0.127), whereas the frequency of sinusoidal or portal fibrosis, lobular necrosis and non-alcoholic steatohepatitis (NASH) were not different. In the multivariate analysis, SIBO (P=0.005) and the presence of a metabolic syndrome (P=0.006) were independent factors of severe hepatic steatosis. CONCLUSION: In morbidly obese patients, bacterial overgrowth prevalence is higher than in healthy subjects and is associated with severe hepatic steatosis.

Small bowel bacterial overgrowth is not seen in healthy adults but is in disabled older adults.

BACKGROUND/AIMS: Small bowel bacterial overgrowth (SBBO) is defined as an abnormal increase in the number of bacteria in the small intestine, and may be occult in older adults. The aim of this study was to determine whether small bowel bacterial overgrowth (SBBO) is found in healthy older people as a concomitant of normal aging or is seen only in disabled or frail older people, excluding patients with intestinal disease and those who had undergone upper intestinal or gastric surgery. METHODOLOGY: Forty-one relatively healthy older people, aged 74.6 +/- 1.7 (mean +/- SE) years, who engage in regular exercise, and 42 variously disabled older people, average age 78.8 +/- 1.1 years, who commute to a day-care center participated in this study. SBBO was determined by a breath hydrogen (H2) test after ingestion of 50g of glucose solution dissolved in 200mL of water. Physical activity was judged from the number of steps walked per day as measured by a pedometer. Food intake was assessed by an interview. RESULTS: No SBBO-positive subject was seen among the healthy, while 11 (25.6%) of the disabled older adults were positive. The number of steps/day taken by the disabled subjects was extremely low, only 22.3% of that of the healthy (P<0.001). No significant difference was seen between the groups in food intake. The mean age of the SBBO-positive patients was relatively high, 81.5 +/- 2.2 years, and 5 (45.4%) of them were underweight, with a BMI<18.5. CONCLUSIONS: Our results and previous studies indicate that SBBO is seen only in patients with intestinal disease and disabled or frail older people.