LAUSR

BackgroundRecent studies have suggested that potential aberrant alterations in the gastrointestinal microbiome contribute to the development of cardiovascular disease, specifically hypertension. Bariatric surgery produces significant sustained weight loss and hypertension resolution likely through multiple mechanisms which includes beneficial changes in the gut microbiome. We hypothesized that the type of prophylactic antibiotic given for bariatric surgery could impact the resolution rate of hypertension by altering the post-operative gastrointestinal microflora.MethodsA retrospective analysis of adult bariatric patients who underwent Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) between 2012 and 2016 was conducted. The standard antibiotic prophylaxis was cefazolin, or clindamycin in patients with a penicillin allergy. Univariate analyses were performed comparing the differing peri-operative antibiotic treatments with resolution of hypertension at 2-week (± 1 week), 6-week (± 2 weeks), 3-month (± 2 weeks), 6-month (± 6 weeks), and 1-year (± 2 months) follow-up appointments. The criterion for resolution of hypertension was no longer requiring medication at time of follow-up.ResultsIn total, 123 RYGB and 88 SG patients were included. No significant differences were found between cefazolin and clindamycin regarding hypertension resolution rates after SG. However, patients who underwent RYGB and received clindamycin had a significantly higher rate of hypertension resolution compared to cefazolin. This effect started at 2 weeks post-operatively (52.4% vs. 23.5% respectively, p = 0.008) and persisted up to the 1-year (57.9% vs. 44.0% respectively, p = 0.05).ConclusionProphylactic peri-operative, intravenous clindamycin was associated with significantly increased resolution of post-operative hypertension compared to cefazolin. This finding was not observed in SG patients. Future studies are needed to confirm the mechanism of action for this novel finding is due to the differing modifications of the gastrointestinal microflora after RYGB resulting from the specific peri-operative antibiotic administered.