Roux-Y Gastric Bypass and Sleeve Gastrectomy directly change gut microbiota composition independent of surgery type

Abstract

Bariatric surgery in morbid obesity, either through sleeve gastrectomy (SG) or Roux-Y gastric bypass (RYGB), leads to sustainable weight loss, improvement of metabolic disorders and changes in intestinal microbiota. Yet, the relationship between changes in gut microbiota, weight loss and surgical procedure remains incompletely understood. We determined temporal changes in microbiota composition in 45 obese patients undergoing crash diet followed by SG ( n = 22) or RYGB ( n = 23). Intestinal microbiota composition was determined before intervention (baseline, S1), 2 weeks after crash diet (S2), and 1 week (S3), 3 months (S4) and 6 months (S5) after surgery. Relative to S1, the microbial diversity index declined at S2 and S3 ( p < 0.05), and gradually returned to baseline levels at S5. Rikenellaceae relative abundance increased and Ruminococcaceae and Streptococcaceae abundance decreased at S2 ( p < 0.05). At S3, Bifidobacteriaceae abundance decreased, whereas those of Streptococcaceae and Enterobacteriaceae increased ( p < 0.05). Increased weight loss between S3-S5 was not associated with major changes in microbiota composition. No significant differences appeared between both surgical procedures. In conclusion, undergoing a crash diet and bariatric surgery were associated with an immediate but temporary decline in microbial diversity, with immediate and permanent changes in microbiota composition, independent of surgery type.

Hafnia alvei HA4597 Strain Reduces Food Intake and Body Weight Gain and Improves Body Composition, Glucose, and Lipid Metabolism in a Mouse Model of Hyperphagic Obesity

“…Our recent study also found that the ClpB gene was depleted in gut microbiota in obese subjects [11]. Furthermore, weight loss and decreased plasma cholesterol after Roux-Y gastric bypass and sleeve gastrectomy were associated with an increased prevalence of Enterobacteriaceae in the microbiota of patients six months after bariatric surgery [31].…”

Bariatric Surgery in Obesity: Effects on Gut Microbiota and Micronutrient Status

“…Regarding the relative abundance and beta-diversity of gut bacteria, no significant differences were reported between patients undergoing either RYGB or VSG prior to surgery, after 1 week or after 6 months postoperatively. Patients experienced similar weight loss after both interventions, which might explain the same changes observed in GM composition, irrespective of surgery type [82].…”

Changes in Faecal Short-Chain Fatty Acids after Weight-Loss Interventions in Subjects with Morbid Obesity

“…Changes in the gut microbiome composition have been reported in several studies in obese subjects, but there is no agreement concerning the type of deviation and causal relations [3,5]. Changes of the microbiota composition after conservative and surgical weight-loss have also been reported [10,13,14]. The increasing degree of dysbiosis after treatment indicates that the treatment does not reset the microbiota, in fact it is the opposite [35].…”

“…An imbalance in the pattern, e.g., in the saccharolytic fermentation characterized by an increase in the main straight SCFA (acetic-, propionic, and butyric-acids) versus the proteolytic fermentation, characterized by an increase in the branched SCFA (isobutyric-isovaleric-, and isocaproicacids), may signify alterations in the microbial functions that may be associated with either gut health or disease [1,2,[6][7][8][9]. Knowledge of faecal SCFA in subjects with morbid obesity and the changes after a combined conservative and surgical intervention is limited [4,[10][11][12][13][14]. An unbalance in the SCFA pattern before or after weight-reducing treatment might have unfavorable health effects that necessitate interventions.…”