Ayesha Shah1,2, Nicholas J Talley3, Natasha Koloski1,2, Graeme A Macdonald1,2, Bradley J Kendall1,2, Erin R Shanahan1,2, Marjorie M Walker3, Simon Keely3, Michael P Jones4, Mark Morrison1,5, Gerald J Holtmann1,2. 1. Department of Gastroenterology and Hepatology, Princess Alexandra Hospital, Brisbane, Qld, Australia. 2. Faculty of Medicine and Faulty of Health and Behavioural Sciences, University of Queensland, Brisbane, Qld, Australia. 3. Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW, Australia. 4. Psychology Department, Macquarie University, Ryde, NSW, Australia. 5. Diamantina Institute, University of Queensland, Brisbane, Qld, Australia.
Abstract
BACKGROUND: Small intestinal bacterial overgrowth may play a role in gastrointestinal and non-gastrointestinal diseases. AIMS: To use quantitative polymerase chain reaction (qPCR) to determine and compare bacterial loads of duodenal biopsies in asymptomatic controls, and patients with functional gastrointestinal disorders (FGIDs) and inflammatory bowel disease (IBD) including ulcerative colitis (UC) and Crohn's disease (CD). To define effects of gastric acid inhibition on bacterial load, explore links of bacterial load and gastrointestinal symptoms in response to a standardised nutrient challenge and compare bacterial load with glucose breath test results. METHODS: In 237 patients (63 controls, 84 FGID and 90 IBD), we collected mucosal samples under aseptic conditions during endoscopy extracted and total DNA. Bacterial load metric was calculated utilising qPCR measurements of the bacterial 16S rRNA gene, normalised to human beta-actin expression. Standard glucose breath test and nutrient challenge test were performed. RESULTS: The duodenal microbial load was higher in patients with FGID (0.22 ± 0.03) than controls (0.07 ± 0.05; P = 0.007) and patients with UC (0.01 ± 0.05) or CD (0.02 ± 0.09), (P = 0.0001). While patients treated with proton pump inhibitors (PPI) had significantly higher bacterial loads than non-users (P < 0.05), this did not explain differences between patient groups and controls. Bacterial load was significantly (r = 0.21, P < 0.016) associated with the symptom response to standardised nutrient challenge test. Methane, but not hydrogen values on glucose breath test were associated with bacterial load measured utilising qPCR. CONCLUSIONS: Utilising qPCR, a diagnosis of FGID and treatment with PPI were independently associated with increased bacterial loads. Increased bacterial loads are associated with an augmented symptom response to a standardised nutrient challenge.
BACKGROUND: Small intestinal bacterial overgrowth may play a role in gastrointestinal and non-gastrointestinal diseases. AIMS: To use quantitative polymerase chain reaction (qPCR) to determine and compare bacterial loads of duodenal biopsies in asymptomatic controls, and patients with functional gastrointestinal disorders (FGIDs) and inflammatory bowel disease (IBD) including ulcerative colitis (UC) and Crohn's disease (CD). To define effects of gastric acid inhibition on bacterial load, explore links of bacterial load and gastrointestinal symptoms in response to a standardised nutrient challenge and compare bacterial load with glucose breath test results. METHODS: In 237 patients (63 controls, 84 FGID and 90 IBD), we collected mucosal samples under aseptic conditions during endoscopy extracted and total DNA. Bacterial load metric was calculated utilising qPCR measurements of the bacterial 16S rRNA gene, normalised to humanbeta-actin expression. Standard glucose breath test and nutrient challenge test were performed. RESULTS: The duodenal microbial load was higher in patients with FGID (0.22 ± 0.03) than controls (0.07 ± 0.05; P = 0.007) and patients with UC (0.01 ± 0.05) or CD (0.02 ± 0.09), (P = 0.0001). While patients treated with proton pump inhibitors (PPI) had significantly higher bacterial loads than non-users (P < 0.05), this did not explain differences between patient groups and controls. Bacterial load was significantly (r = 0.21, P < 0.016) associated with the symptom response to standardised nutrient challenge test. Methane, but not hydrogen values on glucose breath test were associated with bacterial load measured utilising qPCR. CONCLUSIONS: Utilising qPCR, a diagnosis of FGID and treatment with PPI were independently associated with increased bacterial loads. Increased bacterial loads are associated with an augmented symptom response to a standardised nutrient challenge.
Authors: Arjun Gandhi; Ayesha Shah; Michael P Jones; Natasha Koloski; Nicholas J Talley; Mark Morrison; Gerald Holtmann Journal: Gut Microbes Date: 2021 Jan-Dec
Authors: Michael P Jones; Ayesha Shah; Marjorie M Walker; Natasha A Koloski; Gerald Holtmann; Nicholas J Talley Journal: United European Gastroenterol J Date: 2021-10-15 Impact factor: 4.623
Authors: Uday C Ghoshal; Sanjeev Sachdeva; Ujjala Ghoshal; Asha Misra; Amarender Singh Puri; Nitesh Pratap; Ayesha Shah; M Masudur Rahman; Kok Ann Gwee; Victoria P Y Tan; Tahmeed Ahmed; Yeong Yeh Lee; B S Ramakrishna; Rupjyoti Talukdar; S V Rana; Saroj K Sinha; Minhu Chen; Nayoung Kim; Gerald Holtmann Journal: Indian J Gastroenterol Date: 2022-10-10