Partial Leptin Reduction: An Emerging Weight Loss Paradigm

Effect of Sinetrol® Xpur on metabolic health and adiposity by interactions with gut microbiota: a randomized, open label, dose-response clinical trial

BACKGROUND

Sinetrol® Xpur is a polyphenolic ingredient rich in citrus flavonoids that has shown weight loss effects in previous studies. The dose dependent nature, gut microbial actions of this product has not been explored previously, thus presented in this study.

METHODS

In this open label study, we evaluated the effect of Sinetrol® Xpur supplementation on healthy but overweight/obese adults (20-50 yrs) for 16 weeks. Participants (n = 20) were randomly allocated to a high dose group (HD, 1800 mg/day) or low dose group (LD, 900 mg/day) of the product for 16 weeks. Fat composition, gut microbial composition, were evaluated using MRI and 16S rDNA sequencing respectively at week 1 and 16.

RESULTS

We observed HDL, HbA1C, LDL and leptin improved significantly over 16 weeks, irrespective of the dosage. There was a trend for decrease in visceral adipose tissue (VAT), BMI over time and body weight displayed a trend for dose dependent decrease. Eubacterium xylanophilum, Ruminococcacea UCG-004 genus which increased in HD and LD respectively were negatively associated to VAT. Both doses increased butyrate producers such as Eubacterium ruminantium and Ruminococcaceae NK4A214 genus.

CONCLUSIONS

Overall chronic supplementation of Sinetrol® Xpur, irrespective of their dose improved HDL, HbA1c, LDL and leptin and tended to decrease visceral adipose tissue via changes in gut microbiota. Trial registration number NCT03823196.

Effect of preoperative intragastric balloon treatment on perioperative and postoperative outcomes after laparoscopic sleeve gastrectomy: A retrospective cohort study

<b><br>Introduction:</b> Intragastric balloon (IGB) insertion is used as a bridging therapy in patients with body mass index (BMI) ≥ 50 kg/m2 . We arranged a retrospective study to evaluate whether pre-operative IGB treatment influences perioperative and postoperative weight loss outcomes after laparoscopic sleeve gastrectomy (SG), and especially to evaluate the impact of post - IGB percentage of excessive weight loss (%EWL) on postoperative %EWL.</br> <b><br>Materials and methods:</b> Patients who underwent IGB placement followed by laparoscopic SG were divided into the following groups considering %EWL after IGB: Group 1 <=10.38%; Group 2 >10.38% and <=17.27%; Group 3 >17.27% and <=24.86%; Group 4 >24.86%. 1 year after SG data were collected. The following parameters were compared between groups: operative time, total blood loss, length of stay and weight, BMI, percentage of total weight loss (%TWL), %EWL.</br> <b><br>Results:</b> There were no statistically significant differences between groups in perioperative results. Post-SG %EWL was the highest in intermediate groups: 2 and 3. Post-treatment results were observed: body weight and BMI were the lowest in Group 4 and the highest in Group 1. Post-treatment %EWL was the highest in Group 4, the lowest in Group 1 and grew gradually in subsequent groups.</br> <b><br>Discussion:</b> The study confirmed the impact of weight loss on IGB on postoperative results. The study showed that %EWL after the IGB treatment influences %EWL after SG and most of all affects definitive %EWL after two-stage treatment and it could be a foreshadowing factor of these outcomes.</br> <b><br>Importance:</b> The importance of research for the development of the field %EWL after IGB influences the final BMI and final weight, which means that patients with the greatest %EWL after IGB are more likely to have the greatest postoperative weight loss and overall weight loss.</br>.

Recent progress on action and regulation of anorexigenic adipokine leptin

Organismal energy balance is controlled by inter-tissue communication mediated by the nervous system and hormones, the disruption of which causes metabolic syndrome exemplified by diabetes and obesity. Fat-storing adipose tissue, especially those located in subcutaneous white adipose tissue, secretes leptin in a proportion of fat mass, inhibiting the accumulation of organismal fat by suppressing appetite and promoting energy expenditure. With a prevalence of obesity that exhibits hyperleptinemia, most of the investigation on leptin has been focused on how it works and how it does not, which is expected to be a clue for treating obesity. In contrast, how it is synthesized, transported, and excreted, all of which are relevant to the homeostasis of blood leptin concentration, are not much understood. Of note, acute leptin reduction after hyperleptinemia in the context of obesity exhibited a beneficial effect on obesity and insulin sensitivity, indicating that manipulation of circulating leptin level may provide a therapeutic strategy. Technological advances such as "omics" analysis combined with sophisticated gene-engineered mice studies in the past decade enabled a deeper understanding of leptin's action in more detail. Here, we summarize the updated understanding of the action as well as regulation of leptin and point out the emerging direction of research on leptin.

In vivo Protein Interference: Oral Administration of Recombinant Yeast-Mediated Partial Leptin Reduction for Obesity Control

Obesity-related diseases are always the major health problems that concern the whole world. Serial studies have reported that obesity development is closely related to the out-of-control leptin encoded by the obesity gene (ob). The latest report declaimed “Less Is More,” a model explaining that partial leptin reduction triggers leptin sensitization and contributes to obesity control. Here, we came up with a novel concept, in vivo protein interference (iPRTi), an interesting protein knock-down strategy for in vivo partial leptin reduction. First, the specific immune response against leptin induced by the oral administration of ob recombinant yeast was confirmed. Subsequentally, leptin resistance was observed in diet-induced obese mice, and oral administration with ob recombinant yeast declined the circulating leptin and reduced significantly the body weight gain. To further investigate whether the iPRTi strategy is capable of obesity management, the diet-induced obese mice were administrated with ob recombinant yeast. All the indexes examined including the circulating leptin, triglyceride, and total cholesterol, as well as food intake and weight gain, demonstrated a positive effect of the iPRTi strategy on obesity control. In short, this study provides a novel strategy for the potential application of recombinant yeast for the therapy of obese individuals with leptin resistance.

Impact of preoperative weight loss achieved by gastric balloon on peri- and postoperative outcomes of bariatric surgery in super-obese patients: a retrospective matched-pair analysis

Background

An intragastric balloon is used to cause weight loss in super-obese patients (BMI > 60 kg/m²) prior to bariatric surgery. Whether weight loss from intragastric balloon influences that from bariatric surgery is poorly studied.

Methods

In this retrospective, single-center study, the effects of intragastric balloon in 26 patients (BMI 69.26 ± 6.81) on weight loss after bariatric surgery (primary endpoint), postoperative complications within 30 days, hospital readmission, operation time, and MTL30 (secondary endpoints) were evaluated. Fifty-two matched-pair patients without intragastric balloon prior to bariatric surgery were used as controls.

Results

Intragastric balloon resulted in a weight loss of 17.3 ± 14.1 kg (BMI 5.75 ± 4.66 kg/m²) with a nadir after 5 months. Surgical and postoperative outcomes including complications were comparable between both groups. Total weight loss was similar in both groups (29.0% vs. 32.2%, p = 0.362). Direct postoperative weight loss was more pronounced in the control group compared to the gastric balloon group (29.16 ± 7.53% vs 23.78 ± 9.89% after 1 year, p < 0.05 and 32.13 ± 10.5% vs 22.21 ± 10.9% after 2 years, p < 0.05), who experienced an earlier nadir and started to regain weight during the follow-up.

Conclusion

A multi-stage therapeutic approach with gastric balloon prior to bariatric surgery in super-obese patients may be effective to facilitate safe surgery. However, with the gastric balloon, pre-treated patients experienced an attenuated postoperative weight loss with an earlier nadir and earlier body weight regain. This should be considered when choosing the appropriate therapeutic regime and managing patients’ expectations.

Impaired leptin responsiveness in the nucleus accumbens of leptin-overexpressing transgenic mice with dysregulated sucrose and lipid preference independent of obesity

While hypothalamic leptin resistance can occur prior to establishment of obesity, clarification is needed as to whether the impaired response to leptin in the reward-related nuclei occurs independently of obesity. To answer this question, we attempted to dissociate the normally coexisting leptin resistance from obesity. We investigated phenotypes of leptin-overexpressing transgenic mice fed for 1 week with 60 % high-fat diet (HFD) (LepTg-HFD1W mice). After 1 week, we observed that LepTg-HFD1W mice weighed as same as wild type (WT) mice fed standard chow diet (CD) for 1 week (WT-CD1W mice). However, compared to WT-CD1W mice, LepTg-HFD1W mice exhibited attenuated leptin-induced anorexia, decreased leptin-induced c-fos immunostaining in nucleus accumbens (NAc), one of important site of reward system, decreased leptin-stimulated pSTAT3 immunostaining in hypothalamus. Furthermore, neither sucrose nor lipid preference was suppressed by leptin in LepTg-HFD1W mice. On the contrary, leptin significantly suppressed both preferences in WT mice fed HFD (WT-HFD1 W mice). These results indicate that leptin responsiveness decreases in NAc independently of obesity. Additionally, in this situation, suppressive effect of leptin on the hedonic feeding results in impaired regulation. Such findings suggest the impaired leptin responsiveness in NAc partially contributes to dysregulated hedonic feeding behavior independently of obesity.

Leptin Receptors Are Not Required for Roux-en-Y Gastric Bypass Surgery to Normalize Energy and Glucose Homeostasis in Rats

Sensitization to the adipokine leptin is a promising therapeutic strategy against obesity and its comorbidities and has been proposed to contribute to the lasting metabolic benefits of Roux-en-Y gastric bypass (RYGB) surgery. We formally tested this idea using Zucker fatty fa/fa rats as an established genetic model of obesity, glucose intolerance, and fatty liver due to leptin receptor deficiency. We show that the changes in body weight in these rats following RYGB largely overlaps with that of diet-induced obese Wistar rats with intact leptin receptors. Further, food intake and oral glucose tolerance were normalized in RYGB-treated Zucker fatty fa/fa rats to the levels of lean Zucker fatty fa/+ controls, in association with increased glucagon-like peptide 1 (GLP-1) and insulin release. In contrast, while fatty liver was also normalized in RYGB-treated Zucker fatty fa/fa rats, their circulating levels of the liver enzyme alanine aminotransferase (ALT) remained elevated at the level of obese Zucker fatty fa/fa controls. These findings suggest that the leptin system is not required for the normalization of energy and glucose homeostasis associated with RYGB, but that its potential contribution to the improvements in liver health postoperatively merits further investigation.