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

PURPOSE: 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. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Comparative Study of Resting Metabolic Rate and Plasma Amino Acid Profile in Patients Who Underwent Laparoscopic Roux-en-Y Gastric Bypass and Laparoscopic Sleeve Gastrectomy: 6-Month Follow-up Study.

PURPOSE: Laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic sleeve gastrectomy (LSG) are the most common techniques for treatment of morbid obesity. However, a few studies have compared the energy expenditure and plasma amino acid profile after LRYGB and LSG. The present study was conducted to assess the resting metabolic rate (RMR) and plasma amino acid profile in obese patients who underwent LRYGB and LSG before and 6 months after the surgery in order to compare these changes from baseline between the two procedures. MATERIALS AND METHODS: Forty-three adult obese patients participated in this study (LRYGB = 22 and LSG = 21) and were followed up for 6 months. RMR was measured by indirect calorimetry. The plasma amino acid profile was determined using high-performance liquid chromatography (HPLC). RESULTS: Mean percent excess weight loss (%WL) were 22.8 ± 4.5% and 23.3 ± 5.7% in LRYGB and LSG, respectively. RMR reduced significantly from baseline by - 459 ± 202 kcal/day in LRYGB and - 500 ± 262 kcal/day in LSG. RMR reduced beyond the expected decrease in both procedures. A decreasing trend was observed in the plasma concentration of branched-chain amino acids (BCAA), aromatic amino acids (AAA), and amino acid index (AAI) in both techniques. There was no significant difference in weight, RMR analysis, and amino acid change from baseline between LRYGB and LSG. CONCLUSION: Our results showed that the effects of LRYGB and LSG on RMR and amino acid profile were comparable.