Changes in the Gut Microbiota Composition and Their Relation to Dietary Intake After Bariatric Surgery

Prior studies have demonstrated that both dietary components and bariatric surgery modify the gut microbiota's composition. However, there is a scarcity of research that has examined the relationship between post-surgical dietary intake and changes in the gut microbiota. The aim of this study was to assess changes in gut microbiota following bariatric surgery and examine their association with postoperative dietary intake.

The present study involved a sample of 42 adult women who were potential candidates for bariatric surgery, i.e., laparoscopic Roux-en-Y gastric bypass (LRYGB) or sleeve gastrectomy (LSG). The assessment of dietary intake was conducted through the use of three-day food records, both at baseline and six months following the surgical procedure. The gut microbiota was determined through the detection of 16S ribosomal RNA (16S rRNA) gene sequencing.

After six months, a significant increase in abundance of Firmicutes (P = 0.01), Bifidobacterium (P = 0.01), and Ruminococcus (P = 0.04) in the LSG group was found. In contrast to the observed rise in Enterobacteria (P = 0.02) levels in the LRYGB group, no significant changes were detected in the composition of other gut microbiota over the 6-month monitoring period subsequent to LRYGB. The results of our study indicate that there is not a statistically significant relationship between dietary consumption and changes in the composition of the gut microbiota in individuals who have undergone LRYGB and LSG.

Our findings suggest that there may not be a significant correlation between dietary intake following LRYGB and LSG, and the observed alterations in the gut microbiota during a six-month period of observation. Nevertheless, it is important to acknowledge that the sample size utilized in our study was limited, potentially leading to reduced statistical power and the possibility of yielding findings that do not accurately reflect reality.