Clinical Presentation of Small Intestinal Bacterial Overgrowth from Aerodigestive Tract Bacteria Versus Colonic-Type Bacteria: A Comparison Study.

BACKGROUND: Small Intestinal Bacterial Overgrowth (SIBO) is a heterogenous syndrome from excessive bacteria in the small intestine lumen. It is unknown if differences in type of bacterial overgrowth lead to differences in symptoms. METHODS: Patients with suspected SIBO were recruited prospectively. Exclusion criteria were probiotics, antibiotics, or bowel prep in preceding 30 days. Clinical characteristics, risk factors, and labs were collected. Proximal jejunal aspiration via upper enteroscopy was performed. Aerodigestive tract (ADT) SIBO was defined as > 105 CFU/mL of oropharyngeal and respiratory bacteria. Colonic-type SIBO was defined as > 104 CFU/mL of distal small bowel and colon bacteria. Aims were to compare symptom profiles, clinical complications, labs, and underlying risk factors between ADT and colonic-type SIBO. KEY RESULTS: We consented 166 subjects. Aspiration was not obtained in 22 and SIBO was found in 69 (49%) of 144 subjects. Daily abdominal distention trended towards more prevalent in ADT SIBO versus colonic-type SIBO (65.2% vs 39.1%, p = 0.09). Patient symptom scores were similar. Iron deficiency was more prevalent in ADT SIBO (33.3% vs 10.3%, p = 0.04). Subjects with colonic-type SIBO were more likely to have a risk factor for colonic bacteria colonization (60.9% vs 17.4%, p = 0.0006). Subjects with ADT SIBO were more likely to have a risk factor for diminished gastric acid (91.3% vs 67.4%, p = 0.02). CONCLUSIONS & INFERENCES: We found differences in iron deficiency and underlying risk factors between ADT and colonic-type SIBO. However, distinct clinical profiles remained elusive. Future research is needed to develop validated symptom assessment tools and distinguish cause from correlation.

Delayed Gastric Emptying Is Not Associated with a Microbiological Diagnosis of Small Intestinal Bacterial Overgrowth.

BACKGROUND: Clinical symptoms of patients with small intestinal bacterial overgrowth (SIBO) may overlap with symptoms of gastroparesis. Prior studies suggest delayed small intestinal transit is associated with SIBO, but have not shown an association between delayed gastric emptying and SIBO. However, these studies have generally relied on the indirect method of breath testing to diagnose SIBO. AIMS: The aim of this study was to examine the association between a microbiological diagnosis of SIBO and delayed gastric emptying by scintigraphy. METHODS: In a single-center retrospective study of previous research participants who presented for small bowel enteroscopy for diagnostic evaluation of SIBO, we identified 73 participants who underwent gastric emptying study by scintigraphy. A microbiological diagnosis of SIBO was made in patients based on culture results of jejunal aspirates. Clinical symptoms were assessed using the total gastroparesis cardinal symptom index (GCSI) score. We compared delayed gastric emptying, 2- and 4-h gastric retention, and gastroparesis symptoms between patients with and without a microbiological diagnosis of SIBO. KEY RESULTS: Among 29 participants with SIBO and 44 without SIBO, 33 (45%) had evidence of delayed gastric emptying. There was no significant association between a microbiological diagnosis of SIBO and delayed gastric emptying by scintigraphy. Percent retained at 2 and 4 h, and total GCSI scores did not differ significantly between those with and without SIBO. CONCLUSIONS: Although delayed gastric emptying is common in patients with suspected SIBO, gastric emptying is not associated with a microbiological diagnosis of SIBO.

Functional connectivity of the cortical swallowing network in humans.

INTRODUCTION: Coherent fluctuations of blood oxygenation level dependent (BOLD) signal have been referred to as "functional connectivity" (FC). Our aim was to systematically characterize FC of underlying neural network involved in swallowing, and to evaluate its reproducibility and modulation during rest or task performance. METHODS: Activated seed regions within known areas of the cortical swallowing network (CSN) were independently identified in 16 healthy volunteers. Subjects swallowed using a paradigm driven protocol, and the data analyzed using an event-related technique. Then, in the same 16 volunteers, resting and active state data were obtained for 540 s in three conditions: 1) swallowing task; 2) control visual task; and 3) resting state; all scans were performed twice. Data was preprocessed according to standard FC pipeline. We determined the correlation coefficient values of member regions of the CSN across the three aforementioned conditions and compared between two sessions using linear regression. Average FC matrices across conditions were then compared. RESULTS: Swallow activated twenty-two positive BOLD and eighteen negative BOLD regions distributed bilaterally within cingulate, insula, sensorimotor cortex, prefrontal and parietal cortices. We found that: 1) Positive BOLD regions were highly connected to each other during all test conditions while negative BOLD regions were tightly connected among themselves; 2) Positive and negative BOLD regions were anti-correlated at rest and during task performance; 3) Across all three test conditions, FC among the regions was reproducible (r>0.96, p<10(-5)); and 4) The FC of sensorimotor region to other regions of the CSN increased during swallowing scan. CONCLUSIONS: 1) Swallow activated cortical substrates maintain a consistent pattern of functional connectivity; 2) FC of sensorimotor region is significantly higher during swallow scan than that observed during a non-swallow visual task or at rest.

Pyloric Functional Lumen Imaging Probe Measurements Are Dependent on Balloon Position.

Background/Aims: The functional lumen imaging probe (FLIP) device has been used to assess pyloric dysfunction in patients with gastroparesis. We aim to investigate whether varying FLIP catheter positions affect pyloric FLIP measurements. Methods: Patients undergoing endoscopy for chronic unexplained nausea and vomiting (CUNV) or gastroparesis were prospectively enrolled. FLIP balloon was adjusted for 3 positions within the pylorus: (1) proximal position, 75% of FLIP balloon in the duodenum and 25% in the antrum; (2) middle position, 50% in the duodenum and 50% in the antrum; and (3) distal position, 25% in the duodenum and 75% in the antrum. Pylorus cross-sectional area (CSA), intra-bag pressure (P), and distensibility indices (DI) were measured for 30, 40, and 50-mL balloon volumes. Fluoroscopic images were obtained to confirm FLIP balloon geometry. Data was analyzed separately using FLIP Analytic and customized MATLAB software. Results: Twenty-two patients with CUNV (n = 4) and gastroparesis (n = 18) were enrolled. Pressures were significantly higher in the proximal position compared to the middle and distal positions. CSA measurements were significantly higher at the proximal and middle positions for 30-mL and 40-mL volume compared to the distal position values. DI values were significantly lower at the proximal positions for 40-mL and 50-mL distensions when compared to the middle and distal positions. Fluoroscopic images confirmed increased balloon bending when placed mostly in the duodenum. Conclusions: FLIP balloon position within the pylorus directly affects balloon geometry which significantly affects P, CSA, and DI measurements. Standardized pyloric FLIP protocols and balloon design adjustments are needed for the continued application of this technology to the pylorus.

Evaluation of timed barium esophagram after per-oral endoscopic myotomy to predict clinical response.

Background and study aims The aim of this study was to evaluate whether timed barium esophagram within 24 hours post-per-oral endoscopic myotomy (POEM) (TBE-PP) could predict clinical outcomes. Patients and methods This was a single-center retrospective study of prospectively collected data on consecutive patients with ≥ 6-month follow-up who underwent POEM followed by TBE-PP. Esophageal contrast retention 2 minutes after TBE-PP was assessed as Grade 1 (< 10 %), 2 (10 %-49 %), 3 (50 %-89 %) or 4 (> 90 %). Eckardt score, esophagogastroduodenoscopy (EGD), high-resolution manometry (HRM) and function lumen imaging probe (FLIP) of the esophagogastric junction (EGJ) were obtained at baseline. These tests along with pH testing of antisecretory therapy were repeated 6 and 24 months after POEM. Clinical response by Eckardt score ≤ 3, EGJ-distensibility index (EGJ-DI) > 2.8 mm 2 /mm Hg, and integrated relaxation pressure (IRP) < 15 mm Hg and incidence of gastroesophageal reflux disease (GERD) were compared by transit time. Results Of 181 patients (58 % male, mean 53 ±â€Š17 yr), TBE-PP was classified as Grade 1 in 122 (67.4 %), Grade 2 in 41 (22.7 %), Grade 3 in 14 (7.7 %) and Grade 4 in 4 (2.2 %). At 6 months, overall clinical response by ES (91.7 %), IRP (86.6 %), EGJ-DI (95.7 %) and the diagnosis of GERD (68.6 %) was similar between Grade 1 and Grade 2-4 TBE-PP. At 24 months, Grade 1 had a higher frequency of a normal IRP compared to Grades 2-4 (95.7 % vs. 60 %, P  = 0.021) but overall response by ES (91.2 %), EGJ-DI (92.3 %) and the diagnosis of GERD (74.3 %) were similar. Conclusions Contrast emptying rate by esophagram after POEM has limited utility to predict clinical response or risk of post-procedure GERD.

Neural correlates of successful encoding identified using functional magnetic resonance imaging.

Neural activity that occurs during the creation of a new memory trace can be observed using functional magnetic resonance imaging (fMRI). Event-related designs have been used to demonstrate that activity in prefrontal and medial temporal lobe areas is associated with successful memory storage. Here we contrasted activity associated with encoding success and encoding effort. Participants viewed a series of 150 words but attempted to remember only half of them. Encoding effort was manipulated using a cue in the form of a letter (R or F) presented after each word to instruct participants either to remember or to forget that word. Increased activity in left inferior prefrontal cortex was observed when words were followed by the cue to remember. In contrast, increased left medial temporal lobe activity was observed for words that were successfully recalled later. These results show that fMRI correlates of the intention to encode a word are different from fMRI correlates of whether that encoding is successful. Prefrontal activation was strongly associated with intentional verbal encoding, whereas left medial temporal activation was crucial for the encoding that actually led to successful memory on the subsequent test.

Diagnosis and management of small intestinal bacterial overgrowth.

Small intestinal bacterial overgrowth (SIBO) can result from failure of the gastric acid barrier, failure of small intestinal motility, anatomic alterations, or impairment of systemic and local immunity. The current accepted criteria for the diagnosis of SIBO is the presence of coliform bacteria isolated from the proximal jejunum with >10(5) colony-forming units/mL. A major concern with luminal aspiration is that it is only one random sampling of the small intestine and may not always be representative of the underlying microbiota. A new approach to examine the underlying microbiota uses rapid molecular sequencing, but its clinical utilization is still under active investigation. Clinical manifestations of SIBO are variable and include bloating, flatulence, abdominal distention, abdominal pain, and diarrhea. Severe cases may present with nutrition deficiencies due to malabsorption of micro- and macronutrients. The current management strategies for SIBO center on identifying and correcting underlying causes, addressing nutrition deficiencies, and judicious utilization of antibiotics to treat symptomatic SIBO.

Unsedated transnasal endoscopy with ultrathin endoscope as a screening tool for research studies.

OBJECTIVES/HYPOTHESIS: Asymptomatic subjects volunteering for research studies are generally stratified as healthy based on a questionnaire, medical interviewing, and physical examination. The aim of this study was to evaluate the prevalence of upper gastrointestinal (GI) abnormalities in healthy asymptomatic volunteers using unsedated transnasal esophagogastroduodenoscopy (T-EGD) with an ultrathin endoscope as an additional screening tool. STUDY DESIGN: A prospective study from one academic medical center with extensive experience in T-EGD. METHODS: Consecutive 150 subjects volunteering for research studies were initially screened by using a gastroesophageal reflux disease (GERD) questionnaire, interviewing, and examination. Based on these, they were stratified as healthy asymptomatic volunteers or with GERD. Unsedated T-EGD was then performed by a faculty member who was blinded to the results of the initial assessment. RESULTS: On initial assessment using GERD questionnaire, medical interviewing, and physical examination, of the total 150 consecutive research volunteers, 83 (average age 33 ± 16 years; 46 females, 37 males) subjects were healthy asymptomatic volunteers and 67 (average age 36 ± 15 years; 35 females, 32 males) had symptoms of GERD. On T-EGD, GI pathology was found in 15 of 83 (18%) healthy asymptomatic volunteers as compared to 24 of 67 (36%) stratified as having GERD (P < .01). The esophageal abnormalities found in healthy asymptomatic volunteers were esophagitis (13.3%), Barrett's esophagus (2.4%), hiatus hernia (2.4%), and gastritis (2.4%). CONCLUSIONS: A small but significant number of asymptomatic subjects have abnormal upper GI findings. Hence, transnasal unsedated endoscopy can be considered as a screening tool to stratify subjects as healthy, especially when considering them for research studies.

Bilateral carotid artery dissection after dental work.

Carotid artery dissection has been reported to occur spontaneously and after many types of neck trauma. A case patient is presented who developed a right-sided oculosympathetic palsy and was found to have bilateral carotid artery dissection after she visited her dentist. To the best of our knowledge, this case represents the first report of bilateral carotid dissection following dental work.