Bariatric Surgery as Treatment Strategy of Obesity in Saudi People: Effects of Gut Microbiota

Impact of bariatric surgery on gut microbiota in obese patients: A systematic review

BACKGROUND

Obesity is a multi-factorial disease linked to various metabolic disorders, including insulin resistance, type-2 diabetes (T2D) and cardiovascular diseases. Traditional treatments often show limited long-term success, while bariatric surgery has emerged as the most effective intervention for sustained weight loss and comorbidity improvement. Alterations in gut microbiota may significantly contribute to these metabolic improvements.

OBJECTIVE

This systematic review was aimed at evaluating changes in gut microbiota composition before and after bariatric surgery and their association with clinical outcomes, including weight loss, insulin sensitivity and lipid metabolism.

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a comprehensive search of PubMed, Scopus, Web of Science and clinicaltrials.gov databases was conducted for studies published between 2004 and 2024. Keywords included "bariatric surgery," "gut microbiota" and "obesity." Inclusion criteria focused on human studies with pre and post-surgical microbiota analysis. Non-human studies, pediatric populations and studies without microbiota assessment were excluded. Data extraction covered microbiota profiles, metabolic outcomes and clinical markers.

RESULTS

Total 27 articles and 28 clinical trials met the inclusion criteria. Pre-surgery, obese patients exhibited dysbiosis characterized by reduced microbial diversity and imbalances in key bacterial phyla. Post-surgery, especially after Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG), patients showed increased microbial diversity, reduced Firmicutes and elevated beneficial bacteria such as Akkermansia muciniphila and short-chain fatty acid (SCFA) producing bacteria. These microbiota changes were correlated with significant improvements in weight loss, insulin sensitivity and lipid profiles. However, some studies reported inconsistent or modest microbiota changes.

CONCLUSION

Bariatric surgery leads to significant gut microbiota alterations that are closely linked to metabolic improvements, including enhanced glucose control and lipid metabolism. However, the long-term sustainability of these microbial changes remains unclear. Longitudinal studies are essential to determine whether these alterations persist over time and how they continuously impact metabolic health. Further research should explore targeted microbiota interventions to maintain beneficial microbial profiles post-surgery.

Comparison of Complications and Mortality in Patients Undergoing Laparoscopic Sleeve Gastrectomy With and Without Omentopexy

BACKGROUND

Among bariatric surgeries, laparoscopic sleeve gastrostomy (LSG) has gained good global acceptance, but this surgery, like any other invasive procedure, has side effects. Various techniques have been tested to reduce these complications, which are used under the title of stapler line reinforcement (SLR). The purpose of this research is to compare the bleeding, leakage, mortality, food intolerance, re-hospitalization, and post-operative invasive therapeutic interventions in LSG surgery in two groups with and without omentopexy method.

METHODS

In this retrospective cohort study, the patients who underwent LSG were included in the study and were compared in two groups with omentopexy and without omentopexy in terms of complications. The patients were followed up during the first year after the operation, and the patients were examined in terms of complications, including bleeding, leakage, mortality, food intolerance, re-hospitalization, and post-operative invasive therapeutic interventions.

RESULTS

In terms of bleeding (p = 0.263) and the frequency of leak cases (p = 0.286), no significant difference was observed between the two groups, but the treatment measures performed to control the leak had a significant difference between the two groups (p = 0.013). The need for re-admission was significantly higher (p = 0.017) in the group without omentopexy, and the need for re-surgery was also significantly different (p = 0.001) between the two groups. The frequency of food intolerance was significantly higher (p = 0.001) in the group without omentopexy, and the frequency of mortality was no statistically significant difference with the group with omentopexy (p = 0.304).

CONCLUSIONS

The results of this study showed that the need for more aggressive interventions (laparotomy) to control bleeding and leak is less in the group with omentopexy, also the chance of re-hospitalization and re-surgery after omentopexy is reduced, and food intolerance disorder is less in this group. Therefore, the findings of this study show that LSG with omentopexy has fewer side effects than without omentopexy.

Nutritional status of Saudi obese patients undergoing laparoscopic sleeve gastrectomy, one-year follow-up study

Bariatric surgery has significantly increased globally as an effective treatment for severe obesity. Nutritional deficits are common among candidates for bariatric surgery, and follow-up of nutritional status is critically needed for post-surgery healthcare management. This observational prospective study was conducted at King Khalid University Hospital in Riyadh. Samples were collected pre- and post-laparoscopic sleeve gastrectomy (LSG), with the visit intervals divided into four visits: pre-surgery (0M), 3 months (3M), 6 months (6M) and 12 months (12M). Food intake and eating patterns significantly changed during the first year (P < 0·001). The mean energy intake at 3M post-surgery was 738·3 kcal, significantly lower than the pre-surgery energy intake of 2059 kcal. Then, it increased gradually at 6M and 12M to reach 1069 kcal (P < 0·00). The intake of Fe, vitamin B12 and vitamin D was below the dietary reference intake recommendations, as indicated by the 24-hour dietary recall. The prevalence of 25 (OH) vitamin D deficiency improved significantly from pre- to post-surgery (P < 0·001). Vitamin B12 deficiency was less reported pre-LSG and improved steadily towards a sufficient post-surgery status. However, 35·7 % of participants were deficient in Fe status, with 28·6% being female at higher levels than males. While protein supplementation decreased significantly over the 12M follow-up, the use of vitamin supplements dramatically increased at 3 and 6M before declining at 12M. Fe and vitamin B12 were the most popular supplements after vitamin D. This study confirms the necessity for individualised dietary plans and close monitoring of candidates' nutritional status before and after bariatric surgery.

Intussusception Within a Jejunostomy With Closed Loop Obstruction: A Case Report

Jejunojejunal intussusception is a rare yet severe complication of Roux-en-Y gastric bypass (RYGBP) surgery. We are presenting a unique case of retrograde jejunal intussusception with a closed-loop blockage and an associated abdominal herniation that occurred two years after a laparoscopic RYGBP. The patient presented with abdominal pain, nausea, and vomiting, prompting a clinical diagnosis and a biphasic contrast-enhanced computed tomography (CT) scan, which later revealed a complicated jejunal intussusception with signs of ischemia showing decreased wall enhancement and distal collapsed jejunal walls with complete closed-loop bowel obstruction. The case was successfully managed through emergent laparoscopy to repair the hernia and reduce the intussusception, after which the postoperative period was unremarkable. This article aims to raise awareness about this rare but significant postoperative complication and stress the importance of early medical attention in similar cases.

Insight of the Biopharmaceutical Implication of Sleeve Gastrectomy on Levothyroxine Absorption in Hypothyroidism Patients

PURPOSE

The growing rate of obesity led to an increased number of bariatric surgeries (BS) as a treatment option for obesity. The gastrointestinal tract (GIT) changes following BS can impact many drugs' absorption. Levothyroxine (LT4) is a synthetic thyroxine (T4) replacement used commonly as tablets to manage hypothyroidism disorder, which is more prevalent among patients with obesity. This study aims to examine the LT4 oral tablet form therapy after sleeve gastrectomy.

MATERIALS AND METHODS

A retrospective cohort study was conducted in multi-center. The LT4 doses and TSH and T4 levels were compared before and after BS. The post-surgery readings were categorized into three periods: (one to three months), (four to six months), and (> six ) months after surgery. ANOVA test was used for analysis.

RESULTS

A total of 14374 patients who underwent BS from (1/2019 to 3/2022) were screened for eligibility, and n = 101 participants matched the inclusion criteria. The TSH and T4 were not statistically significant differences before and after surgery (P-values of 0.4864 and 0.5970, respectively). However, the doses significantly differed before and after surgery in all the follow-up time point periods (P < 0.002).

CONCLUSION

The LT4 required doses significantly reduced after sleeve gastrectomy, which can be related to the improved endogenous thyroid production in patients with obesity. However, the abnormality of the GIT induced by the sleeve gastrectomy may affect the exogenous LT4 absorption. Using liquid forms of LT4 while monitoring the thyroid function parameters can optimize the treatment after the procedure.

Visceral adipose tissue and risk of nonalcoholic fatty liver disease: A Mendelian randomization study

OBJECTIVE

Observational studies have shown that visceral adipose tissue (VAT) can increase the risk of nonalcoholic fatty liver disease (NAFLD). However, the causality of this association remains unclear. Therefore, this study aimed to explore the causal association between VAT and NAFLD.

DESIGN

We obtained single-nucleotide polymorphisms strongly associated with VAT (n = 325,153) from large-scale genome-wide association studies. Summary-level data for NAFLD (2275 cases and 375,002 controls) was available from the FinnGen consortium. We applied two-sample Mendelian randomization (MR) to determine the causal association between VAT and NAFLD. The random-effects inverse-variance weighted (IVW) method was used as the main MR approach, with alternate methods including the weighted median (WM) approach and MR-Egger regression. In addition, we conducted sensitivity analyses to assess the robustness of MR analyses.

RESULTS

Genetically predicted higher VAT mass is causally associated with a higher risk of NAFLD. The three analysis results of MR were as follows: IVW (β = 0.665, odds ratio [OR] = 1.944, 95% confidence interval [CI] = 1.482-2.550, p = 1.58e-06], WM (β = 0.615, OR = 1.849, 95% CI = 1.272-2.689, p = 1.29e-03), and MR-Egger (β = 1.250, OR = 3.490, 95% CI = 1.522-7.998, p = 3.52e-03). In the sensitivity analysis, the data showed heterogeneity (p < 0.05) but no pleiotropy (p = 0.145).

CONCLUSION

This study provided genetic evidence that higher VAT mass causally associated with a higher risk of NAFLD. The amount of VAT could be reduced using a therapeutic strategy for managing NAFLD.