Small-bowel bacterial overgrowth in elderly people: clinical significance and response to treatment.

Duodenal-jejunal bacterial overgrowth is increasingly recognized in old age but its clinical significance is poorly defined. In this study, 16 elderly subjects were selected on the basis of an abnormal lactulose breath hydrogen test from a series of 27 in whom there was some reason to suspect malabsorption. In 12 of these 16 cases, pentagastrin tests showed normal gastric acid secretion and in 12 cases the small bowel was radiologically normal. Nutritional assessment, anthropometric measurements, culture of small-bowel aspirates, 14C-triolein breath tests and blood xylose tests were performed before and after 4 to 6 months of cyclical antibiotic therapy. Initially all patients except two showed evidence of malabsorption. After antibiotic treatment alone, 13 patients gained in weight and body fat. There were significant rises in the mean levels of haemoglobin, serum protein and calcium. Blood xylose test levels increased in 14 cases, reaching normal in all except one, whereas 14C-triolein excretion also increased in 14 and reached normal in 12 out of 16 cases. The breath hydrogen test reverted to normal in all cases and bacterial overgrowth was eliminated in 10 out of 11. The mouth-to-caecum transit time was prolonged initially (mean 190 min) and was unaffected by therapy (mean 196 min). Malabsorption and undernutrition are significant features of small-bowel overgrowth in the elderly and can be specifically corrected by antibiotic treatment. The clinical effect can be equally severe in elderly patients with or without an anatomical defect of the small bowel.(ABSTRACT TRUNCATED AT 250 WORDS)     

The diagnosis of small bowel bacterial overgrowth in elderly patients.

OBJECTIVE: To examine the frequency of small bowel bacterial overgrowth in elderly subjects. DESIGN: Prospective observational study. SETTING: Department of Health Care of the Elderly in a university teaching hospital. PATIENTS: Thirteen elderly control subjects having undergone normal gastroscopy with normal hematology and anthropometry; 39 consecutive referrals of elderly patients with clinical or biochemical evidence of malnutrition. MAIN OUTCOME MEASURES: Duodenal bacterial counts and the 14C-glycocholate, hydrogen, and 14C-xylose breath tests. RESULTS: Five of the 13 control subjects and 21 of 39 patients with malnutrition had high duodenal bacterial counts (greater than 10(5) organisms/mL), whereas only seven patients were judged to have clinically significant bacterial overgrowth. The 14C-xylose breath test showed a high specificity (89%) but a low sensitivity (30%) when compared with the results of duodenal culture. The hydrogen breath tests and the 14C-glycocholate test showed a similar picture of moderately high specificity and low sensitivity (77% and 20%, respectively, for the hydrogen breath test, 76% and 33%, respectively, for the 14C-glycocholate test). CONCLUSIONS: A positive xylose breath test was the best predictor of high duodenal bacterial counts. However, since many elderly subjects have high duodenal bacterial counts, the overdiagnosis of bacterial overgrowth syndrome will result if duodenal culture is relied upon exclusively.     

Small bowel bacterial overgrowth in strongyloidiasis.

Small bowel bacterial growth was studied in patients with strongyloidiasis, and the results were compared to controls. We concluded that in strongyloidiasis there is small bowel bacterial overgrowth, and so it should be considered in the pathogenesis of some of the gastrointestinal manifestations and complications of strongyloidiasis.     

Lactose malabsorption in the elderly: role of small intestinal bacterial overgrowth

OBJECTIVE: The prevalence of lactose malabsorption (LM) is increased in the elderly, although the mechanisms responsible are still a matter of speculation. The objective of this study was to investigate the possible roles of reduced functional small intestinal absorptive area, lactase deficiency and small intestinal bacterial overgrowth (SIBO). MATERIAL AND METHODS: Twenty Caucasian (Anglo-Celtic), asymptomatic, well-nourished, elderly volunteers (median age 79 years, range 70-94 years) with no clinically apparent predisposition to SIBO underwent a 50 g lactose breath hydrogen test (LBHT) and mannitol absorption test, the latter as an index of functional small intestinal absorptive area. Those with LM additionally underwent bacteriological assessment of small intestinal secretions and mucosal biopsy, to assess the contribution of SIBO and lactase deficiency, respectively, to the pathogenesis of LM in individual cases. The prevalence of SIBO was also determined in elderly subjects without LM. Twenty asymptomatic younger subjects (median age 29 years, age range 18-35 years) served as controls. All subjects were "hydrogen producers" in response to lactulose. RESULTS: LM was evident in 10/20 (50%) elderly subjects and 1/20 (5%) younger subjects (p=0.003). Mannitol absorption did not differ significantly in elderly and younger subjects or in elderly subjects with and without LM. SIBO was documented in 9/10 (90%) elderly subjects with LM; eradication was associated with resolution of LM. Lactase deficiency was evident in only one elderly subject with LM. SIBO was evident in 2/10 (20%) elderly subjects without LM (p=0.005 compared to those with LM). Lactulose breath hydrogen test identified only 2/11 (18%) elderly subjects with SIBO. CONCLUSIONS: Increased prevalence of LM in the elderly is mostly due to clinically non-apparent SIBO, rather than mucosal factors. The lactulose breath hydrogen test cannot be relied upon to identify elderly subjects with SIBO, even in those without an anatomical predisposition.     

Lactose malabsorption in the elderly: Role of small intestinal bacterial overgrowth

Objective. The prevalence of lactose malabsorption (LM) is increased in the elderly, although the mechanisms responsible are still a matter of speculation. The objective of this study was to investigate the possible roles of reduced functional small intestinal absorptive area, lactase deficiency and small intestinal bacterial overgrowth (SIBO). Material and methods. Twenty Caucasian (Anglo-Celtic), asymptomatic, well-nourished, elderly volunteers (median age 79 years, range 70–94 years) with no clinically apparent predisposition to SIBO underwent a 50 g lactose breath hydrogen test (LBHT) and mannitol absorption test, the latter as an index of functional small intestinal absorptive area. Those with LM additionally underwent bacteriological assessment of small intestinal secretions and mucosal biopsy, to assess the contribution of SIBO and lactase deficiency, respectively, to the pathogenesis of LM in individual cases. The prevalence of SIBO was also determined in elderly subjects without LM. Twenty asymptomatic younger subjects (median age 29 years, age range 18–35 years) served as controls. All subjects were “hydrogen producers” in response to lactulose. Results. LM was evident in 10/20 (50%) elderly subjects and 1/20 (5%) younger subjects (p=0.003). Mannitol absorption did not differ significantly in elderly and younger subjects or in elderly subjects with and without LM. SIBO was documented in 9/10 (90%) elderly subjects with LM; eradication was associated with resolution of LM. Lactase deficiency was evident in only one elderly subject with LM. SIBO was evident in 2/10 (20%) elderly subjects without LM (p=0.005 compared to those with LM). Lactulose breath hydrogen test identified only 2/11 (18%) elderly subjects with SIBO. Conclusions. Increased prevalence of LM in the elderly is mostly due to clinically non-apparent SIBO, rather than mucosal factors. The lactulose breath hydrogen test cannot be relied upon to identify elderly subjects with SIBO, even in those without an anatomical predisposition.     

Clinical significance of delirium subtypes in older people.

OBJECTIVE: to examine the relative frequency and outcome of clinical subtypes of delirium in older hospital patients. DESIGN: prospective observational study. SETTING: acute geriatric unit in a teaching hospital. SUBJECTS: 94 patients with delirium from a prospective study of 225 admissions. MEASUREMENTS: clinical subtypes of delirium were determined according to predefined criteria. Characteristics examined in these subgroups included illness severity on admission, prior cognitive impairment, mortality, duration of hospital stay and hospital-acquired complications. RESULTS: of the 94 patients, 20 (21%) had a hyperactive delirium, 27 (29%) had a hypoactive delirium, 40 (43%) had a mixed hypoactive-hyperactive psychomotor pattern and seven (7%) had no psychomotor disturbance. There were significant differences between the four groups in illness severity (P < 0.05), length of hospital stay (P < 0.005) and frequency of falls (P < 0.05). Patients with hypoactive delirium were sicker on admission, had the longest hospital stay and were most likely to develop pressure sores. Patients with hyperactive delirium were most likely to fall in hospital. There were no differences in aetiological factors between the groups. CONCLUSION: outcomes of hospitalization differ in different clinical subtypes of delirium.     

Small intestinal bacterial overgrowth

Small intestinal bacterial overgrowth (SIBO) syndrome is characterized in its florid form by diarrhoea and weight loss. The most common underlying factors are dysmotility, small intestinal obstruction, blind or afferent loops. Small intestinal bacterial overgrowth can be diagnosed by: 1) culture of jejunum aspirate for bacterial counts, 2) 14C-D-xylose breath testing, 3) non-invasive hydrogen breath testing using glucose or lactulose or 4) 14C-glycocholic acid breath testing. The treatment usually consists of the eradication of bacterial overgrowth with repeated course of antimicrobials, correction of associated nutritional deficiencies and, when possible, correction of the underlying predisposing conditions.     

Small intestinal bacterial overgrowth

Despite the current increase in interest in the role of the microbiota in health and disease and the recognition, for over 50 years, that an excess of colonic-type flora in the small intestine could lead to a malabsorption syndrome, small intestinal overgrowth remains poorly defined. This lack of clarity owes much to the difficulties that arise in attempting to arrive at consensus with regard to the diagnosis of this condition: there is currently no gold standard and the commonly available methodologies (the culture of jejunal aspirates and a variety of breath tests) suffer from considerable variations in their performance and interpretation, leading to variations in the prevalence of overgrowth in a variety of clinical contexts. Treatment is similarly supported by a scant evidence base and the most commonly used antibiotic regimens owe more to custom than clinical trials.     

Small intestinal bacterial overgrowth

Small intestinal bacterial overgrowth (SIBO) syndrome is characterized in its florid form by diarrhoea and weight loss. The most common underlying factors are dysmotility, small intestinal obstruction, blind or afferent loops. Small intestinal bacterial overgrowth can be diagnosed by: 1) culture of jejunum aspirate for bacterial counts, 2) ¹⁴C-D-xylose breath testing, 3) non-invasive hydrogen breath testing using glucose or lactulose or 4) ¹⁴C-glycocholic acid breath testing. The treatment usually consists of the eradication of bacterial overgrowth with repeated course of antimicrobials, correction of associated nutritional deficiencies and, when possible, correction of the underlying predisposing conditions.     

前庭自旋转试验对老年眩晕的临床分析

目的探讨前庭自旋转试验(VAT)对老年前庭源性眩晕的临床意义。方法把完成VAT检查的123例前庭源性眩晕患者按年龄分为老年组67例(≥60岁)和中青年组56例(<60岁),同期随机选取30例健康老年人作为对照组。比较入选者VAT各项指标的特异性和临床特点。结果老年组VAT异常率约占92.5%,明显高于对照组,差异有统计学意义(P<0.01)。老年组VAT≥2项指标异常率明显高于对照组,差异均有统计学意义(P<0.01)。老年组前庭中枢性损害、前庭中枢+外周性损害异常率明显高于青年组,差异有统计学意义(P<0.05)。结论 VAT是适合老年人的一种前庭源性眩晕检查的方法,有助于老年前庭源性疾病的定位诊断。     

Enteric bacterial flora and bacterial overgrowth syndrome

Under certain conditions, colonic bacterial flora can colonize the upper small bowel in concentrations sufficient to cause mucosal damage and malabsorption of nutrients, vitamin B12, and fat-soluble vitamins. This situation, known as small bowel bacterial overgrowth syndrome (SBBOS) may be an under-appreciated cause of malnutrition in elderly people. The diagnosis of SBBOS should be considered when patients with known or suspected predisposing conditions have symptoms or findings compatible with this syndrome. However, proof of small bowel bacterial overgrowth requires specialized testing that is not readily available. Moreover, disagreement persists as to how best to test definitively for this disease. Therefore, on a practical level and despite the potential drawbacks of such a decision, SBBOS is usually diagnosed when a compatible syndrome responds to an empirical trial of appropriate oral antibiotics. Improvements on this approach to SBBOS will be built on more widespread access to sensitive, specific, and less cumbersome testing than is currently available.     

Clinical correlates of sway in elderly people living at home.

Postural sway has been noted to increase with advancing age and to correlate with a wide variety of clinical features. The relationships between sway and various clinical features were explored in a group of elderly subjects living at home and free from neurological illness and severe incapacity. Each subject underwent a thorough physical examination and sway was measured in the anteroposterior and lateral planes with eyes open and closed using a modified Wright's ataxiameter. Vibration sense was the only clinical feature to show a consistent relationship with all 4 measurements of sway in men. Age showed only a weak and inconsistent relationship to sway in both men and women. Weak but inconsistent relationships were noted between sway and mental function, tone, passive joint movement, antidepressant and tranquilliser therapy. This suggests that dorsal column function is of prime importance in the maintenance of balance and that the previously noted increase in postural sway with advancing age may have been exaggerated by the presence of disease processes.     

Small intestinal bacterial overgrowth in patients with rheumatoid arthritis.

OBJECTIVES--To examine the microflora of the upper small intestine in patients with seropositive rheumatoid arthritis (RA) using a combination of microbial cultivation and tests for microbial metabolic activity. METHODS--Twenty five patients with seropositive RA, 12 achlorhydric control subjects, and 11 control subjects with normal gastric acid secretion were investigated. Disease activity was evaluated in the patients with RA by three different indices. Eight (32%) of the patients with RA had hypochlorhydria or achlorhydria. The acid secretory capacity was determined with pentagastrin stimulation. A modified Crosby capsule was used to obtain biopsy specimens and samples of intestinal fluid from the proximal jejunum; aerobic and anaerobic microbial cultivation of mucosal specimens/intestinal fluid was carried out, and gas production and microflora associated characteristics in jejunal fluid were determined. Additionally, a bile acid deconjugation breath test was performed. RESULTS--Subjects with at least one of the following findings were considered to have bacterial overgrowth: positive bile acid deconjugation test; growth of Enterobacteriaceae; positive gas production; or low tryptic activity. By these criteria half of the patients with RA with hypochlorhydria or achlorhydria and half of the achlorhydric controls had bacterial overgrowth. Thirty five per cent of the patients with RA with normal gastric acid secretion had bacterial overgrowth compared with none of the normal controls. Disease activity indices and rheumatoid factor titres were significantly higher in patients with RA with bacterial overgrowth than in those without. CONCLUSIONS--A high frequency of small intestinal bacterial overgrowth was found in patients with RA; it was associated with a high disease activity and observed in patients with hypochlorhydria or achlorhydria and in those with normal acid secretion.     

Duodenal bacterial overgrowth during treatment in outpatients with omeprazole.

The extent of duodenal bacterial overgrowth during the pronounced inhibition of acid secretion that occurs with omeprazole treatment is unknown. The bacterial content of duodenal juice of patients treated with omeprazole was therefore examined in a controlled prospective study. Duodenal juice was obtained under sterile conditions during diagnostic upper endoscopy. Aspirates were plated quantitatively for anaerobic and aerobic organisms. Twenty five outpatients with peptic ulcer disease were investigated after a 5.7 (0.5) weeks (mean (SEM)) treatment course with 20 mg (nine patients) or 40 mg (16 patients). The control group consisted of 15 outpatients referred for diagnostic endoscopy without prior antisecretory treatment. No patient in the control group had duodenal bacterial overgrowth. In the omeprazole group bacterial overgrowth (> or = 10(5) cfu/ml) was found in 14 (56%) patients (p = 0.0003). The number of bacteria (log10) in duodenal juice in patients treated with omeprazole was distinctly higher (median 5.7; range < 2-8.7) when compared with the control group (median < 2; range < 2-5.0; p = 0.0004). As well as orally derived bacteria, faecal type bacteria were found in seven of 14 and anaerobic bacteria in three of 14 patients. Bacterial overgrowth was similar with the two doses of omeprazole. These results indicate that duodenal bacterial overgrowth of both oral and faecal type bacteria occurs often in ambulatory patients treated with omeprazole. Further studies are needed to determine the clinical significance of these findings, particularly in high risk groups during long term treatment with omeprazole.     

Small intestinal bacterial overgrowth syndrome

Human intestinal microbiota create a complex polymi-crobial 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 gastro-intestinal tract. There...     

Small intestinal bacterial overgrowth syndrome

Opinion statement Small intestinal bacterial overgrowth is found in many conditions and may present with malabsorption, diarrhea, and malnutrition. Whereas dietary modifications and supplements might help, the primary treatment strategy is the judicious use of antibiotics. The most effective antibiotics, shown either empirically or by clinical trials, are the quinolones, tetracycline, amoxicillin with clavulanic acid, clindamycin, and metronidazole. In an unpredictable fashion, some patients fail to respond to one of these antibiotics, but often will respond to a second. These conditions are often chronic and require periodic or cyclical treatment. In some conditions seen in the elderly or in hypochlorhydric patients the small intestinal bacterial overgrowth is inconsequential and does not require therapy. Surgical management is reserved for the select situations in which there is a clear-cut structural defect.     

Role of intestinal bacterial overgrowth and intestinal motility in bacterial translocation in experimental cirrhosis.

BACKGROUND: Intestinal bacterial overgrowth (IBO) is related to small bowel motility and has been involved in the pathogenesis of bacterial translocation (BT) in experimental models, and both overgrowing gut flora and translocating bacteria to mesenteric lymph nodes are common features in cirrhosis. OBJECTIVES: The aims of this study were to analyze cecal aerobic bacteria and intestinal transit in cirrhotic rats, and their relationship with BT, evaluating the role of intestinal bacterial overgrowth and small bowel dismotility in the development of BT in experimental cirrhosis. MATERIAL AND METHODS: We included twenty-seven male Sprague-Dawley rats with carbon tetrachloride-induced cirrhosis without ascites and ten controls. Cultures of mesenteric lymph nodes (MLN), peripheral and portal blood, liver, spleen and cecal samples were carried out. Small intestinal transit was determined in ten cirrhotic rats and in ten control rats. RESULTS: The prevalence of bacterial translocation was 56%. Total cecal aerobic bacteria count was significantly higher in cirrhotic rats than in control rats (p < 0.001). Cirrhotic rats with translocated bacteria had higher total aerobic intestinal counts than culture-negative MLN bacteria (p < 0.05). The prevalence of total intestinal bacterial overgrowth in cirrhotic animals was 67%, and 0% in control animals (p < 0.001). According to BT, total IBO was more frequent in cirrhotic rats with BT versus those without BT (93 vs. 33%) (p < 0.001). Of the translocating bacteria, 95.6% were found to be overgrown in the cecum. The small-intestinal transit was slower in cirrhotic rats (60.5 +/- 12.7 cm vs. 81.2 +/- 5.7 cm) than in control animals (p < 0.001). CONCLUSIONS: These results suggest that the increase of intestinal aerobic bacteria in experimental cirrhosis is associated with translocation. In addition, IBO is frequent in cirrhotic rats, and is supposed to play an important role in the development of BT. Impaired motility of the small intestine is a common feature in cirrhosis and may be implicated in the pathogenesis of IBO.