High fat diet induced obesity alters endocannabinoid and ghrelin mediated regulation of components of the endocannabinoid system in nodose ganglia

Cholinergic Neurotransmission Controls Orexigenic Endocannabinoid Signaling in the Gut in Diet-Induced Obesity

The brain bidirectionally communicates with the gut to control food intake and energy balance, which becomes dysregulated in obesity. For example, endocannabinoid (eCB) signaling in the small-intestinal (SI) epithelium is upregulated in diet-induced obese (DIO) mice and promotes overeating by a mechanism that includes inhibiting gut-brain satiation signaling. Upstream neural and molecular mechanism(s) involved in overproduction of orexigenic gut eCBs in DIO, however, are unknown. We tested the hypothesis that overactive parasympathetic signaling at the muscarinic acetylcholine receptors (mAChRs) in the SI increases biosynthesis of the eCB, 2-arachidonoyl-sn-glycerol (2-AG), which drives hyperphagia via local CB1Rs in DIO. Male mice were maintained on a high-fat/high-sucrose Western-style diet for 60 d, then administered several mAChR antagonists 30 min prior to tissue harvest or a food intake test. Levels of 2-AG and the activity of its metabolic enzymes in the SI were quantitated. DIO mice, when compared to those fed a low-fat/no-sucrose diet, displayed increased expression of cFos protein in the dorsal motor nucleus of the vagus, which suggests an increased activity of efferent cholinergic neurotransmission. These mice exhibited elevated levels of 2-AG biosynthesis in the SI, that was reduced to control levels by mAChR antagonists. Moreover, the peripherally restricted mAChR antagonist, methylhomatropine bromide, and the peripherally restricted CB1R antagonist, AM6545, reduced food intake in DIO mice for up to 24 h but had no effect in mice conditionally deficient in SI CB1Rs. These results suggest that hyperactivity at mAChRs in the periphery increases formation of 2-AG in the SI and activates local CB1Rs, which drives hyperphagia in DIO.

The influence of maternal prepregnancy weight and gestational weight gain on the umbilical cord blood metabolome: a case-control study

BACKGROUND

Maternal overweight/obesity and excessive gestational weight gain (GWG) are frequently reported to be risk factors for obesity and other metabolic disorders in offspring. Cord blood metabolites provide information on fetal nutritional and metabolic health and could provide an early window of detection of potential health issues among newborns. The aim of the study was to explore the impact of maternal prepregnancy overweight/obesity and excessive GWG on cord blood metabolic profiles.

METHODS

A case control study including 33 pairs of mothers with prepregnancy overweight/obesity and their neonates, 30 pairs of mothers with excessive GWG and their neonates, and 32 control mother-neonate pairs. Untargeted metabolomic profiling of umbilical cord blood samples were performed using UHPLC‒MS/MS.

RESULTS

Forty-six metabolites exhibited a significant increase and 60 metabolites exhibited a significant reduction in umbilical cord blood from overweight and obese mothers compared with mothers with normal body weight. Steroid hormone biosynthesis and neuroactive ligand‒receptor interactions were the two top-ranking pathways enriched with these metabolites (P = 0.01 and 0.03, respectively). Compared with mothers with normal GWG, in mothers with excessive GWG, the levels of 63 metabolites were increased and those of 46 metabolites were decreased in umbilical cord blood. Biosynthesis of unsaturated fatty acids was the most altered pathway enriched with these metabolites (P < 0.01).

CONCLUSIONS

Prepregnancy overweight and obesity affected the fetal steroid hormone biosynthesis pathway, while excessive GWG affected fetal fatty acid metabolism. This emphasizes the importance of preconception weight loss and maintaining an appropriate GWG, which are beneficial for the long-term metabolic health of offspring.

Influence of Bariatric Surgery on Gut Microbiota Composition and Its Implication on Brain and Peripheral Targets

Obesity remains a significant global health challenge, with bariatric surgery remaining as one of the most effective treatments for severe obesity and its related comorbidities. This review highlights the multifaceted impact of bariatric surgery beyond mere physical restriction or nutrient malabsorption, underscoring the importance of the gut microbiome and neurohormonal signals in mediating the profound effects on weight loss and behavior modification. The various bariatric surgery procedures, such as Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG), act through distinct mechanisms to alter the gut microbiome, subsequently impacting metabolic health, energy balance, and food reward behaviors. Emerging evidence has shown that bariatric surgery induces profound changes in the composition of the gut microbiome, notably altering the Firmicutes/Bacteroidetes ratio and enhancing populations of beneficial bacteria such as Akkermansia. These microbiota shifts have far-reaching effects beyond gut health, influencing dopamine-mediated reward pathways in the brain and modulating the secretion and action of key gut hormones including ghrelin, leptin, GLP-1, PYY, and CCK. The resultant changes in dopamine signaling and hormone levels contribute to reduced hedonic eating, enhanced satiety, and improved metabolic outcomes. Further, post-bariatric surgical effects on satiation targets are in part mediated by metabolic byproducts of gut microbiota like short-chain fatty acids (SCFAs) and bile acids, which play a pivotal role in modulating metabolism and energy expenditure and reducing obesity-associated inflammation, as well as influencing food reward pathways, potentially contributing to the regulation of body weight and reduction in hedonic eating behaviors. Overall, a better understanding of these mechanisms opens the door to developing non-surgical interventions that replicate the beneficial effects of bariatric surgery on the gut microbiome, dopamine signaling, and gut hormone regulation, offering new avenues for obesity treatment.

Dry heat whole Sorghum BRS 305 flour modulate satiety and improves antioxidant response in brain of Wistar rats fed with high-fat high-fructose diet

Sorghum BRS 305 (Sorghum bicolor L. Moench) is a cereal with high tannins and anthocyanins content and keep better the resistant starch when submitted to dry heat treatment. Our objective was to investigate the effects of BRS 305 dry heat treatment whole sorghum flour on satiety and antioxidant response in brain and adipose tissue of Wistar rats fed with a high fat high fructose diet (HFHF). Male Wistar rats were divided in two groups: control (n = 8) and HFHF (n = 16) for eight weeks. After, animals of HFHF group were divided: HFHF (n = 8) and HFHF + BRS 305 sorghum whole flour (n = 8), for 10 weeks. Sorghum consumption reduced gene expression of leptin, resistin, and endocannabinoid receptor 1 type (CB1) in adipose and brain tissues compared to HFHF group. In brain, sorghum consumption also promotes reduction in neuropeptide Y (NPY) gene expression. BRS305 sorghum consumption improved gene expression of sirtuin-1 (SIRT1) in adipose tissue, and in the brain increased heat shock protein 72 (HSP72), erythroid-derived nuclear factor 2 (NRF2), peroxisome proliferator-activated receptor alpha (PPARα), superoxide dismutase (SOD) and catalase activity compared to HFHF. In silicoanalysis showed interaction with PPARα, CB1, and leptin receptors. Advanced glycation end products (AGEs) concentrations in group HFHF + sorghum did not differ from HFHF group. Advanced glycation end products receptors (RAGEs) concentrations did not differ among experimental groups. Then, BRS 305 sorghum submitted to dry treatment was able to modulate gene expression of markers related to satiety and improve antioxidant capacity of rats fed with HFHF diet.

Dietary Fat Modulation of Gut Microbiota and Impact on Regulatory Pathways Controlling Food Intake

Obesity is a multifactorial disease that continues to increase in prevalence worldwide. Emerging evidence has shown that the development of obesity may be influenced by taxonomic shifts in gut microbiota in response to the consumption of dietary fats. Further, these alterations in gut microbiota have been shown to promote important changes in satiation signals including gut hormones (leptin, ghrelin, GLP-1, peptide YY and CCK) and orexigenic and anorexigenic neuropeptides (AgRP, NPY, POMC, CART) that influence hyperphagia and therefore obesity. In this review, we highlight mechanisms by which gut microbiota can influence these satiation signals both locally in the gastrointestinal tract and via microbiota-gut-brain communication. Then, we describe the effects of dietary interventions and associated changes in gut microbiota on satiety signals through microbiota-dependent mechanisms. Lastly, we present microbiota optimizing therapies including prebiotics, probiotics, synbiotics and weight loss surgery that can help restore beneficial gut microbiota by enhancing satiety signals to reduce hyperphagia and subsequent obesity. Overall, a better understanding of the mechanisms by which dietary fats induce taxonomical shifts in gut microbiota and their impact on satiation signaling pathways will help develop more targeted therapeutic interventions in delaying the onset of obesity and in furthering its treatment.

The molecular mechanism of vgf in appetite, lipids, and insulin regulation

Obesity is an indication of an imbalance between energy expenditure and food intake. It is a complicated disease of epidemic proportions as it involves many factors and organs. Sedentary lifestyles and overeating have caused a substantial rise in people with obesity and type 2 diabetes. Thus, the discovery of successful and sustainable therapies for these chronic illnesses is critical. However, the mechanisms of obesity and diabetes and the crosstalk between these diseases are still ambiguous. Numerous studies are being done to study these mechanisms, with updates made frequently. VGF peptide and its derivatives are anticipated to have a role in the development of obesity and diabetes. However, contradictory studies have produced conflicting findings on the function of VGF. Therefore, in this review, we attempt to clarify and explain the role of VGF peptides in the brain, pancreas, and adipose tissue in the development of obesity.

Endocannabinoids and the Gut-Brain Control of Food Intake and Obesity

Gut-brain signaling controls food intake and energy homeostasis, and its activity is thought to be dysregulated in obesity. We will explore new studies that suggest the endocannabinoid (eCB) system in the upper gastrointestinal tract plays an important role in controlling gut-brain neurotransmission carried by the vagus nerve and the intake of palatable food and other reinforcers. A focus will be on studies that reveal both indirect and direct interactions between eCB signaling and vagal afferent neurons. These investigations identify (i) an indirect mechanism that controls nutrient-induced release of peptides from the gut epithelium that directly interact with corresponding receptors on vagal afferent neurons, and (ii) a direct mechanism via interactions between eCBs and cannabinoid receptors expressed on vagal afferent neurons. Moreover, the impact of diet-induced obesity on these pathways will be considered.