Characterization of the Gut Microbial Community of Obese Patients Following a Weight-Loss Intervention Using Whole Metagenome Shotgun Sequencing

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): BHF & NIHR BRC Introduction Obesity is strongly associated with increased risk of heart failure and ischaemic stroke independently of associated co-morbidities. Left atrial (LA) reservoir dysfunction, a marker of atrial distensibility and compliance, is an early pathophysiological change which precedes the onset of cardiovascular disease in patients with obesity. It is unclear whether a weight loss intervention may be sufficient to reverse LA reservoir dysfunction. Purpose To longitudinally assess whether a weight loss intervention normalizes LA reservoir function by cardiac magnetic resonance (CMR) feature-tracking in patients with obesity and only subclinical cardiovascular disease and compared this age and sex matched non-obese normal weight controls. Methods A total of 45 patients with severe obese (age = 45 ± 11 years, body mass index = 39.1 ± 6.7 kg/m2, 51 ± 18 kg of excess body weight [EBW], 67% female) underwent CMR for quantification of LA and left ventricular (LV) size and function before and a median of 373 days following weight loss intervention. Weight loss was achieved by means of a very-low calorie diet (N = 28; 800 kcal/day) or by bariatric surgery (N = 17). A total of N = 27 non-obese healthy controls (age = 41 ± 12 years, body mass index = 22.3 ± 2.4 kg/m2, 75% female) underwent the same CMR protocol once. Results At baseline, patients with obesity displayed signs of atrial myopathy with increased LA volume and reduced LA reservoir function as compared to normal-weight controls (both P < 0.05, Figure 1) alongside increased LV mass and hyper-normal LV ejection fraction [LVEF] (both p < 0.01). As expected, weight loss led to a significant reduction of LA volume and LV mass with normalization of LVEF regardless of the degree of weight loss achieved (all P < 0.05, Figure 2). By contrast, only a large weight loss (>46.6% EBW, in red in Figure 2) was sufficient to improve and normalize the LA reservoir function (P < 0.05, Figure 2). On the other hand, moderate or milder weight loss (in orange and red) had no significant effect on LA reservoir function (both P > 0.05). Conclusion Successful weight loss can completely revert early LA myopathic phenotype in obese patients without known cardiovascular disease although this can be achieved only with larger weight loss targets.

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Paving the way towards a weight‐loss intervention study in obese patients with inflammatory bowel disease

United European Gastroenterology Journal ◽

10.1177/2050640620965113 ◽

2020 ◽

Vol 8 (10) ◽

pp. 1143-1144

Author(s):

Julien Kirchgesner

Keyword(s):

Inflammatory Bowel Disease ◽

Weight Loss ◽

Bowel Disease ◽

Intervention Study ◽

Obese Patients ◽

Weight Loss Intervention ◽

Inflammatory Bowel ◽

The Way

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Expression of macrophage genes within skeletal muscle correlates inversely with adiposity and insulin resistance in humans

Applied Physiology Nutrition and Metabolism ◽

10.1139/apnm-2017-0228 ◽

2018 ◽

Vol 43 (2) ◽

pp. 187-193 ◽

Cited By ~ 4

Author(s):

Dongmei Liu ◽

Flor Elisa Morales ◽

Heidi. B. IglayReger ◽

Mary K. Treutelaar ◽

Amy E. Rothberg ◽

...

Keyword(s):

Gene Expression ◽

Insulin Resistance ◽

Skeletal Muscle ◽

Weight Loss ◽

Adipose Tissue ◽

Insulin Sensitivity ◽

Muscle Tissue ◽

Skeletal Muscle Tissue ◽

Obese Patients ◽

Weight Loss Intervention

Local inflammation in obese adipose tissue has been shown to contribute to insulin resistance; however, the role of macrophage infiltration within skeletal muscle is still debatable. This study aimed to evaluate the association of skeletal muscle macrophage gene expression with adiposity levels and insulin sensitivity in obese patients. Twenty-two nondiabetic obese patients and 23 healthy lean controls were included. Obese patients underwent a 3-month weight loss intervention. Macrophage gene expression in skeletal muscle (quantitative real-time polymerase chain reaction), body composition (dual-energy X-ray absorptiometry), and insulin sensitivity (homeostatic model assessment (HOMA) and oral glucose tolerance test) were compared between groups and their associations were analyzed. To validate skeletal muscle findings, we repeated the analyses with macrophage gene expression in adipose tissue. Expression levels of macrophage genes (CD68, CD11b, CD206, CD16, CD40, and CD163) were lower in skeletal muscle tissue of obese versus lean participants. Macrophage gene expression was also found to be inversely associated with adiposity, fasting insulin, and HOMA (r = −0.4 ∼ −0.6, p < 0.05), as well as positively associated with insulin sensitivity (r = 0.4 ∼ 0.8, p < 0.05). On the other hand, adipose tissue macrophage gene expression showed higher levels in obese versus lean participants, presenting a positive association with adiposity levels. Macrophage gene expression, in both skeletal and adipose tissue samples, was only minimally affected by the weight loss intervention. In contrast with the established positive relationship between adiposity and macrophage gene expression, an unexpected inverse correlation between these 2 variables was observed in skeletal muscle tissue. Additionally, muscle macrophage gene expression was inversely correlated with insulin resistance.

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Gut microbiota characterisation in obese patients before and after bariatric surgery

Beneficial Microbes ◽

10.3920/bm2017.0152 ◽

2018 ◽

Vol 9 (3) ◽

pp. 367-373 ◽

Cited By ~ 15

Author(s):

G. Campisciano ◽

S. Palmisano ◽

C. Cason ◽

M. Giuricin ◽

M. Silvestri ◽

...

Keyword(s):

Bariatric Surgery ◽

Weight Loss ◽

Gastric Bypass ◽

Sleeve Gastrectomy ◽

Gut Microbiota ◽

Good Health ◽

Normal Weight ◽

Obese Patients ◽

Before And After

Intestinal microbiota analysis of obese patients after bariatric surgery showed that Proteobacteria decreased after laparoscopic sleeve gastrectomy (SG), while it increased after laparoscopic gastric bypass (LGB). Comparing to normal weight (NW) patients, obese patients that were selected for SG showed an almost equal amount of Firmicutes and Bacteroidetes and the ratio was not affected by the surgery. Obese patients before LGB showed a predominance of Bacteroidetes, whose amount regained a relative abundance similar to NW patients after surgery. Obese patients before LGB showed the predominance of Bacteroides, which decreased after surgery in favour of Prevotella, a bacterium associated with a healthy diet. The bacteria detected at the highest percentages belonged to biofilm forming species. In conclusion, in this study, we found that the characterization of the gut microbial communities and the modality of mucosal colonisation have a central role as markers for the clinical management of obesity and promote the maintenance of good health and the weight loss.

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