The Effects of One Anastomosis Gastric Bypass Surgery on the Gastrointestinal Tract

One anastomosis gastric bypass (OAGB) is an emerging bariatric procedure, yet data on its effect on the gastrointestinal tract are lacking. This study sought to evaluate the incidence of small-intestinal bacterial overgrowth (SIBO) following OAGB; explore its effect on nutritional, gastrointestinal, and weight outcomes; and assess post-OABG occurrence of pancreatic exocrine insufficiency (PEI) and altered gut microbiota composition. A prospective pilot cohort study of patients who underwent primary-OAGB surgery is here reported. The pre-surgical and 6-months-post-surgery measurements included anthropometrics, glucose breath-tests, biochemical tests, gastrointestinal symptoms, quality-of-life, dietary intake, and fecal sample collection. Thirty-two patients (50% females, 44.5 ± 12.3 years) participated in this study, and 29 attended the 6-month follow-up visit. The mean excess weight loss at 6 months post-OAGB was 67.8 ± 21.2%. The glucose breath-test was negative in all pre-surgery and positive in 37.0% at 6 months (p = 0.004). Positive glucose breath-test was associated with lower reported dietary intake and folate levels and higher vitamin A deficiency rates (p ≤ 0.036). Fecal elastase-1 test (FE1) was negative for all pre-surgery and positive in 26.1% at 6 months (p = 0.500). Both alpha and beta diversity decreased at 6 months post-surgery compared to pre-surgery (p ≤ 0.026). Relatively high incidences of SIBO and PEI were observed at 6 months post-OAGB, which may explain some gastrointestinal symptoms and nutritional deficiencies.

The rise of one anastomosis gastric bypass: insights from surgeons and dietitians

One anastomosis gastric bypass/Mini Gastric Bypass (OAGB/MGB) is an emerging bariatric surgery (BS) technique. We evaluated and compared attitudes of bariatric surgeons and dietitians towards the considerations for choosing BS-type ("Decision-making"), the contributing factors to the rise of OAGB/MGB in Israel ("OAGB/MGB-rise") and notions regarding the occurrence of gastrointestinal (GI) symptoms and nutritional deficiencies following OAGB/MGB. Anonymous online surveys were distributed. The participants were asked to rate by a 10-point Likert scale (0 = not at all; 100 = very much/often) their attitudes towards "Decision-making", "OAGB/MGB-rise" and occurrence of GI symptoms and nutritional deficiencies following OAGB/MGB. For "Decision-making" and "OAGB/MGB-rise", items were considered prioritized where ≥ 50% of the group considered them as 'very-important' (rating ≥ 80). Data on age, sex, years-in-practice and main workplace were also collected. A total of 106 professionals participated in the survey (42 surgeons; 64 dietitians). The respective mean age, years-in-practice and sex were 52.3 ± 8.7 vs. 42.3 ± 9.0 years, 21.0 ± 10.8 vs. 15.5 ± 9.2 years and 85.7% vs. 3.1% males. The inter-observer agreement for prioritized items related to "Decision-making" was fair (Kappa = 0.250; P = 0.257) and both groups prioritized patient's BMI, comorbidities and compliance. The inter-observer agreement for prioritized items related to "OAGB/MGB-rise" was moderate (Kappa = 0.550; P = 0.099) and both groups prioritized ease of performance, shorter operation duration and failure of former restrictive BS. Surgeons reported lower occurrence of nutritional deficiencies and GI symptoms as adverse effects of OAGB/MGB (P ≤ 0.033). The study highlights the views of bariatric surgeons and dietitians concerning factors that underpin the rise of OABG/MGB in Israel and possible rates of GI symptoms and nutritional deficiencies associated with this modality.