1.
Immunometabolism, Micronutrients, and Bariatric Surgery: The Use of Transcriptomics and Microbiota-Targeted Therapies.
Galyean, S, Sawant, D, Shin, AC
Mediators of inflammation. 2020;:8862034
Abstract
BACKGROUND Obesity is associated with the gut microbiota and decreased micronutrient status. Bariatric surgery is a recommended therapy for obesity. It can positively affect the composition of the gut bacteria but also disrupt absorption of nutrients. Low levels of micronutrients can affect metabolic processes, like glycolysis, TCA cycle, and oxidative phosphorylation, that are associated with the immune system also known as immunometabolism. METHODS MEDLINE, PUBMED, and Google Scholar were searched. Articles involving gut microbiome, micronutrient deficiency, gut-targeted therapies, transcriptome analysis, micronutrient supplementation, and bariatric surgery were included. RESULTS Studies show that micronutrients play a pivotal role in the intestinal immune system and regulating immunometabolism. Research demonstrates that gut-targeting therapies may improve the microbiome health for bariatric surgery populations. There is limited research that examines the role of micronutrients in modulating the gut microbiota among the bariatric surgery population. CONCLUSIONS Investigations are needed to understand the influence that micronutrient deficiencies have on the gut, particularly immunometabolism. Nutritional transcriptomics shows great potential in providing this type of analysis to develop gut-modulating therapies as well as more personalized nutrition recommendations for bariatric surgery patients.
2.
Interplay between the Adaptive Immune System and Insulin Resistance in Weight Loss Induced by Bariatric Surgery.
Villarreal-Calderón, JR, Cuéllar, RX, Ramos-González, MR, Rubio-Infante, N, Castillo, EC, Elizondo-Montemayor, L, García-Rivas, G
Oxidative medicine and cellular longevity. 2019;:3940739
Abstract
Low-grade chronic inflammation plays a pivotal role among other pathophysiological mechanisms involved in obesity. Innate and adaptive immune cells undergo systemic proinflammatory polarization that gives rise to an increased secretion of proinflammatory cytokines, which in turn leads to insulin resistance. Bariatric surgery is currently the most effective treatment for obesity, as it brings on significant weight loss, glucose metabolism improvement, and a decrease in systemic inflammation biomarkers. After bariatric surgery, several changes have been reported to occur in adaptive immunity, including reduction in CD4+ and CD8+ T cell counts, a decrease in the Th1/Th2 ratio, an increase in B regulatory cells, and reduction in proinflammatory cytokine secretion. Overall, there seems to be a major shift in several lymphocyte populations from a proinflammatory to an anti-inflammatory phenotype. Furthermore, increased antioxidant activity and reduced lipid and DNA oxidation products have been reported after bariatric surgery in circulating mononuclear cells. This paper highlights the shift in the adaptive immune system in response to weight loss and improved insulin sensitivity, as well as the interplay between immunological and metabolic adaptations as a result of bariatric surgery. Finally, based on data from research, we propose several mechanisms such as changes in adaptive immune cell phenotypes and their by-products, recruitment in adipose tissue, reduced oxidative stress, and modification in metabolic substrate availability as drivers to reduce low-grade chronic inflammation after bariatric surgery in severe obesity.
3.
What Bariatric Surgery Can Teach Us About Endoluminal Treatment of Obesity and Metabolic Disorders.
Kaplan, LM
Gastrointestinal endoscopy clinics of North America. 2017;(2):213-231
Abstract
Bariatric surgical procedures, including gastric bypass, vertical sleeve gastrectomy, and biliopancreatic diversion, are the most effective and durable treatments for obesity. In addition, These operations induce metabolic changes that provide weight-independent improvement in type 2 diabetes, fatty liver disease and other metabolic disorders. Initially thought to work by mechanical restriction of food intake or malabsorption of ingested nutrients, these procedures are now known to work through complex changes in neuroendocrine and immune signals emanating from the gut, including peptide hormones, bile acids, vagal nerve activity, and metabolites generated by the gut microbiota, all collaborating to reregulate appetite, food preference, and energy expenditure. Development of less invasive means of achieving these benefits would allow much greater dissemination of effective, gastrointestinal (GI)-targeted therapies for obesity and metabolic disorders. To reproduce the benefits of bariatric surgery, however, these endoscopic procedures and devices will need to mimic the physiological rather than the mechanical effects of these operations.
4.
Impact of Bariatric Surgery on White Adipose Tissue Inflammation.
Labrecque, J, Laforest, S, Michaud, A, Biertho, L, Tchernof, A
Canadian journal of diabetes. 2017;(4):407-417
Abstract
Excess fat mass accumulation can lead to a wide range of metabolic and cardiovascular complications resulting from dysfunctional adipose tissue (AT). The latter includes immune cell infiltration and altered secretion of anti- and proinflammatory mediators, which contribute to systemic, low-grade inflammation. In this article, we review available literature documenting the impact of surgery-induced weight loss on macrophage infiltration and tissue expression or circulating levels of a broad spectrum of inflammatory mediators. Reports generally show that bariatric surgery may reverse both macrophage infiltration and the altered secretory profile observed in the AT of patients with severe obesity. However, further studies are needed to confirm or elucidate the effects of specific bariatric surgery procedures on white AT inflammation and to shed light on the mechanisms involved in these effects.