Postoperative Changes in Intestinal Microbiota and Use of Probiotics in Roux-en-Y Gastric Bypass and Sleeve Vertical Gastrectomy: An Integrative Review

Abstract

Introduction: Studies suggest that weight loss induced by bariatric surgery and the remission of some comorbidities may be related to changes in the microbiota profile of individuals undergoing this procedure. In addition, there is evidence that manipulation of the intestinal microbiota may prove to be a therapeutic approach against obesity and metabolic diseases. Objective: To verify the changes that occur in the intestinal microbiota of patients undergoing bariatric surgery, and the impact of the usage of probiotics in this population. Methods: Articles published between 2007 and 2017 were searched in Medline, Lilacs and Pubmed with the headings: bariatric surgery, microbiota, microbiome and probiotics, in Portuguese, English and Spanish. Of the 166 articles found, only those studies in adults subjected to either Roux-en-Y gastric bypass or sleeve vertical gastrectomy published in original articles were enrolled. In the end, five studies on the change of intestinal microbiota composition, four on the indirect effects of those changes and three on the probiotics administration on this population were enrolled and characterized. Conclusion: Bariatric surgery provides changes in intestinal microbiota, with a relative increase of the Bacteroidetes and Proteobacteria phyla and reduction of Firmicutes. This is possibly due to changes in the gastro-intestinal flux, coupled with a reduction in acidity, in addition to changes in eating habits. The usage of probiotics seems to reduce the gastro-intestinal symptoms in the post-surgery, favor the increase of vitamin B12 synthesis, as well as potentiate weight loss.

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

“…The same changes were in a previous study based on the same material judged as unfavorable ("bad" dysbiosis) [34]. In contrast to the review by Wagner el al., this study showed a significant increase in the relative amount of the phylum Firmicutes and a non-significant reduction in Bacteroidetes [5]. An abundance of Firmicutes and a high Firmicutes/Bacteroidetes ratio have been associated with obesity and judged as unfavorable [36][37][38].…”

“…At inclusion, the faecal microbiota composition showed a minor deviation from a reference population (a slight degree of dysbiosis) and a further deviation after surgery. 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].…”

“…4 T2: 6 months after surgery. 5 The sum of acetic-, propionic-, and butyric-acids. 6 The sum of isobutyric-, isovaleric-, and isocaproic-acids.…”

“…The gut microbiota and their metabolites, e.g., short-chain fatty acids (SCFA), have health-related effects and have been associated with a wide range of disorders [1,2]. Obesity with comorbidities is one of these microbiota-associated disorders, although a causal relationship has not been documented in humans [3][4][5]. The microbiota and the metabolites might be both health-promoting and health-damaging.…”

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

“…Therapeutic interventions designed to reshape GM structure have gained increasing attention in the last years as they have been found to mitigate the risk/degree of obesity [182]. Modulation of the host GM is achieved through diet and/or administration of probiotics [183].…”