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Beale EO, Horowitz M. Hypothesis: Bolus jejunal feeding via an enteral feeding tube simulates key features of gastric bypass to initiate similar clinical benefits. Nutrition 2022; 94:111537. [PMID: 34920411 DOI: 10.1016/j.nut.2021.111537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 10/24/2021] [Accepted: 11/01/2021] [Indexed: 02/07/2023]
Abstract
BACKGROUND Therapy for obesity and related comorbidities should be clinically effective, widely available and acceptable, and used in conjunction with an optimized lifestyle. Dieting is widely available and acceptable but has poorly sustained clinical efficacy. By contrast, Roux-en-Y gastric bypass (GB) is highly effective but cost and safety concerns limit widespread use. In this article this we discuss the hypothesis that bolus jejunal feeding (BJ) via an enteral feeding tube simulates key features of GB with the potential for similar clinical benefits. We further hypothesize that a practical manner of providing BJ therapeutically is via an externally inapparent orojejunal feeding tube. RATIONALE The first hypothesis is underpinned by the outcomes of research in three fields: 1) investigations into the mechanisms underlying the benefit of GB, 2) studies investigating gastrointestinal physiology and pathophysiology using enteral feeding tubes, and3) investigations into the mechanism underlying involuntary anorexia and weight loss in clinical situations that entail rapid nutrient delivery to the jejunum. There is compelling evidence that a supraphysiologic rate of delivery of nutrient to the jejunum suppresses appetite and energy intake and improves glucose homeostasis, and that these effects can be achieved non-surgically using an enteral feeding tube. The second hypothesis is supported by clinical demonstration of the feasibility of administering intermittent cycles of bolus feeds via an intraorally anchored feeding tube in ambulatory obese adults. CONCLUSION The hypotheses are testable in clinical studies. If validated, BJ could be used to induce the clinical benefits of GB, but without its costs or safety concerns.
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Affiliation(s)
- Elizabeth Ogden Beale
- Division of Endocrinology and Diabetes, Keck School of Medicine, University of Southern California, Los Angeles, California, USA.
| | - Michael Horowitz
- Endocrine and Metabolic Unit, The Royal Adelaide Hospital, University of Adelaide, Adelaide, South Australia, Australia
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Igarashi M, Iwasa K, Hayakawa T, Tsuduki T, Kimura I, Maruyama K, Yoshikawa K. Dietary oleic acid contributes to the regulation of food intake through the synthesis of intestinal oleoylethanolamide. Front Endocrinol (Lausanne) 2022; 13:1056116. [PMID: 36733808 PMCID: PMC9886573 DOI: 10.3389/fendo.2022.1056116] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 12/07/2022] [Indexed: 01/18/2023] Open
Abstract
INTRODUCTION Among the fatty acid ethanolamides (FAEs), oleoylethanolamide (OEA), linoleoylethanolamide (LEA), and palmitoylethanolamide (PEA) are reported to be involved in feeding regulation. In particular, OEA is well characterized as a satiety signal. Following food consumption, OEA is synthesized from oleic acid (OA) via an N-acyl phosphatidylethanolamine-specific phospholipase D-dependent pathway in the gastroenterocytes, and OEA induces satiety by recruiting sensory fibers. Thus, we hypothesized that dietary OA is an important satiety-inducing molecule. However, there has been no direct demonstration of the effect of dietary OA on satiety induction without the influence of the endogenous biosynthesis of OA from stearic acid (SA) or other FAEs. METHODS In this study, we used two experimental diets to test our hypothesis: (i) an OA diet (OAD; 38.4 mg of OA/g and 7.2 mg of SA/g) and (ii) a low OA diet (LOAD; 3.1 mg of OA/g and 42.4 mg of SA/g). RESULTS Relative to mice fed the OAD, mice fed the LOAD for two weeks exhibited reduced levels of jejunal OEA but not jejunal LEA and PEA. The LOAD-fed mice showed an increase in food intake and body weight gain. Moreover, LOAD-induced increase in food intake was immediately observed after the switch from the OAD, whereas these effects were diminished by the switch back to the OAD. Furthermore, treatment with OA and OEA diminished the effects of LOAD on food intake. CONCLUSION Collectively, these results show that dietary OA is a key factor in the reduction of food intake and increase in satiety mediated by OEA signaling.
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Affiliation(s)
- Miki Igarashi
- Advanced Clinical Research Center, Institute of Neurological Disorders, Kawasaki, Japan
- Department of Pharmacology, Faculty of Medicine, Saitama Medical University, Saitama, Japan
- Department of Applied Biological Science, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan
- *Correspondence: Miki Igarashi,
| | - Kensuke Iwasa
- Department of Pharmacology, Faculty of Medicine, Saitama Medical University, Saitama, Japan
| | - Tetsuhiko Hayakawa
- Department of Applied Biological Science, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan
| | - Tsuyoshi Tsuduki
- Department of Bioscience and Biotechnology for Future Bioindustries, Graduate School of Agricultural Science, Tohoku University, Sendai, Japan
| | - Ikuo Kimura
- Department of Applied Biological Science, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan
- Laboratory of Molecular Neurobiology, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Kei Maruyama
- Department of Pharmacology, Faculty of Medicine, Saitama Medical University, Saitama, Japan
| | - Keisuke Yoshikawa
- Department of Pharmacology, Faculty of Medicine, Saitama Medical University, Saitama, Japan
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Poppitt SD, Shin HS, McGill AT, Budgett SC, Lo K, Pahl M, Duxfield J, Lane M, Ingram JR. Duodenal and ileal glucose infusions differentially alter gastrointestinal peptides, appetite response, and food intake: a tube feeding study. Am J Clin Nutr 2017; 106:725-735. [PMID: 28701300 DOI: 10.3945/ajcn.117.157248] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 06/15/2017] [Indexed: 11/14/2022] Open
Abstract
Background: Activation of the ileal brake through the delivery of nutrients into the distal small intestine to promote satiety and suppress food intake provides a new target for weight loss. Evidence is limited, with support from naso-ileal lipid infusion studies.Objective: The objective of the study was to investigate whether glucose infused into the duodenum and ileum differentially alters appetite response, food intake, and secretion of satiety-related gastrointestinal peptides.Design: Fourteen healthy male participants were randomly assigned to a blinded 4-treatment crossover, with each treatment of single-day duration. On the day before the intervention (day 0), a 380-cm multilumen tube (1.75-mm diameter) with independent port access to the duodenum and ileum was inserted, and position was confirmed by X-ray. Subsequently (days 1-4), a standardized breakfast meal was followed midmorning by a 90-min infusion of isotonic glucose (15 g, 235 kJ) or saline to the duodenum or ileum. Appetite ratings were assessed with the use of visual analog scales (VASs), blood samples collected, and ad libitum energy intake (EI) measured at lunch, afternoon snack, and dinner.Results: Thirteen participants completed the 4 infusion days. There was a significant effect of nutrient infused and site (treatment × time, P < 0.05) such that glucose-to-ileum altered VAS-rated fullness, satisfaction, and thoughts of food compared with saline-to-ileum (Tukey's post hoc, P < 0.05); decreased ad libitum EI at lunch compared with glucose-to-duodenum [-22%, -988 ± 379 kJ (mean ± SEM), Tukey's post hoc, P < 0.05]; and increased glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) compared with all other treatments (Tukey's post hoc, P < 0.05).Conclusions: Macronutrient delivery to the proximal and distal small intestine elicits different outcomes. Glucose infusion to the ileum increased GLP-1 and PYY secretion, suppressed aspects of VAS-rated appetite, and decreased ad libitum EI at a subsequent meal. Although glucose to the duodenum also suppressed appetite ratings, eating behavior was not altered. This trial was registered at www.anzctr.org.au as ACTRN12612000429853.
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Affiliation(s)
- Sally D Poppitt
- Human Nutrition Unit, School of Biological Sciences and Department of Medicine,
| | - Hyun Sang Shin
- Human Nutrition Unit, School of Biological Sciences and Department of Medicine
| | - Anne-Thea McGill
- Human Nutrition Unit, School of Biological Sciences and Department of Medicine.,School of Population Health, and
| | | | - Kim Lo
- Plant and Food Research Ltd., Auckland, New Zealand; and
| | - Malcolm Pahl
- Plant and Food Research Ltd., Auckland, New Zealand; and
| | - Janice Duxfield
- Department of Gastroenterology and Hepatology, Auckland City Hospital, Auckland, New Zealand
| | - Mark Lane
- Department of Gastroenterology and Hepatology, Auckland City Hospital, Auckland, New Zealand
| | - John R Ingram
- Plant and Food Research Ltd., Auckland, New Zealand; and
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Moghadam AA, Moran TH, Dailey MJ. Jejunal Infusion of Glucose Decreases Energy Intake to a Greater Extent than Fructose in Adult Male Rats. J Nutr 2016; 146:2124-2128. [PMID: 27581579 PMCID: PMC5037871 DOI: 10.3945/jn.116.231860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 08/04/2016] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Intestinal nutrient infusions result in variable decreases in energy intake and body weight based on nutrient type and specific intestinal infusion site. OBJECTIVE The objective was to test whether an intrajejunal fructose infusion (FRU) would lower energy intake and body weight and induce similar increases in gut hormones as those found after intrajejunal glucose infusions (GLU). METHODS Male Sprague-Dawley rats received an intrajejunal infusion of either an equal kilocalorie load of glucose or fructose (11.4 kcal) or saline (SAL) for 5 d while intake of a standard rodent diet was continuously recorded; body weight was measured daily. Immediately after the infusion on the final day, rats were killed and plasma was collected to measure hormones. RESULTS Daily energy intake was significantly lower in the GLU group than in the SAL group, but the FRU group did not differ from the GLU or SAL groups when the 11.4 kcal of the infusate was included as energy intake. Lower energy intake was due to smaller meal sizes during the infusion period in the GLU group than in the FRU and SAL groups; the FRU and SAL groups did not differ. The percentage of change in body weight was lower in the GLU group than in the FRU and SAL groups. Plasma glucagon-like-peptide 1 (GLP-1) concentrations were greater in the GLU group than in the SAL group; the FRU group did not differ from the GLU or SAL groups. The plasma insulin concentration was greater in the FRU group than in both the GLU and SAL groups. CONCLUSION These results demonstrate that glucose induces a greater decrease in energy intake and increase in GLP-1 at distal intestinal sites than fructose in rats, which may explain differential effects of these monosaccharides between studies when delivered orally or along the proximal to distal axis of the intestine.
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Affiliation(s)
- Alexander A Moghadam
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University, Baltimore MD; and
| | - Timothy H Moran
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University, Baltimore MD; and
| | - Megan J Dailey
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL
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Dailey MJ, Moghadam AA, Moran TH. Nutrient-specific feeding and endocrine effects of jejunal infusions in obese animals. Am J Physiol Regul Integr Comp Physiol 2014; 306:R420-8. [PMID: 24452547 DOI: 10.1152/ajpregu.00410.2013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Intestinal nutrient infusions result in variable decreases in food intake and body weight based on the nutrient type and the specific intestinal infusion site. We previously found that intrajejunal infusions of a fatty acid and glucose, but not casein hydrolysate, decreases food intake and body weight in lean chow-fed laboratory rats. To test whether obese, high fat-fed animals would show similar decreases in food intake and body weight in response to intrajejunal infusions of the same nutrients, equal kilocalorie loads of these nutrients (11.4 kcal) or vehicle were infused into the jejunum of obese, high fat-fed male Sprague-Dawley rats over 7 h/day for 5 consecutive days. Food intake was continuously monitored, and body weight was measured daily. After the infusion on the final day, rats were killed and plasma was collected. Similar to lean chow-fed rats, intrajejunal infusions of linoleic acid (LA) and glucose (Glu), but not casein hydrolysate (Cas), suppressed food intake with no compensatory increase in food intake after the infusion period. In contrast to lean chow-fed rats, only the LA, and not the Glu or Cas, produced decreases in body weight in the obese high fat-fed rat. There also were no differences in plasma glucagon-like peptide-1 levels in any of the nutrient infusion groups compared with saline infusion. These results suggest that there is a differential response to the same nutrients in lean vs. obese animals.
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Affiliation(s)
- Megan J Dailey
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois; and
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Shin HS, Ingram JR, McGill AT, Poppitt SD. Lipids, CHOs, proteins: can all macronutrients put a 'brake' on eating? Physiol Behav 2013; 120:114-23. [PMID: 23911804 DOI: 10.1016/j.physbeh.2013.07.008] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Revised: 01/09/2013] [Accepted: 07/23/2013] [Indexed: 01/18/2023]
Abstract
The gastrointestinal (GI) tract and specifically the most distal part of the small intestine, the ileum, has become a renewed focus of interest for mechanisms targeting appetite suppression. The 'ileal brake' is stimulated when energy-containing nutrients are delivered beyond the duodenum and jejunum and into the ileum, and is named for the feedback loop which slows or 'brakes' gastric emptying and duodeno-jejunal motility. More recently it has been hypothesized that the ileal brake also promotes secretion of satiety-enhancing GI peptides and suppresses hunger, placing a 'brake' on food intake. Postprandial delivery of macronutrients to the ileum, other than unavailable carbohydrates (CHO) which bypass absorption in the small intestine en route to fermentation in the large bowel, is an uncommon event and hence this brake mechanism is rarely activated following a meal. However the ability to place a 'brake' on food intake through delivery of protected nutrients to the ileum is both intriguing and challenging. This review summarizes the current clinical and experimental evidence for activation of the ileal brake by the three food macronutrients, with emphasis on eating behavior and satiety as well as GI function. While clinical studies have shown that exposure of the ileum to lipids, CHOs and proteins may activate GI components of the ileal brake, such as decreased gut motility, gastric emptying and secretion of GI peptides, there is less evidence as yet to support a causal relationship between activation of the GI brake by these macronutrients and the suppression of food intake. The predominance of evidence for an ileal brake on eating comes from lipid studies, where direct lipid infusion into the ileum suppresses both hunger and food intake. Outcomes from oral feeding studies are less conclusive with no evidence that 'protected' lipids have been successfully delivered into the ileum in order to trigger the brake. Whether CHO or protein may induce the ileal brake and suppress food intake has to date been little investigated, although both clearly have GI mediated effects. This review provides an overview of the mechanisms and mediators of activation of the ileal brake and assesses whether it may play an important role in appetite suppression.
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Affiliation(s)
- H S Shin
- Human Nutrition Unit, University of Auckland, Auckland, New Zealand; School of Biological Sciences, University of Auckland, Auckland, New Zealand
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7
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Dailey MJ, Moghadam AA, Moran TH. Jejunal linoleic acid infusions require GLP-1 receptor signaling to inhibit food intake: implications for the effectiveness of Roux-en-Y gastric bypass. Am J Physiol Endocrinol Metab 2011; 301:E1184-90. [PMID: 21917638 PMCID: PMC3233780 DOI: 10.1152/ajpendo.00335.2011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Roux-en-Y gastric bypass surgery results in sustained decreases in food intake and weight loss. A key component is likely the direct delivery of nutrients to the jejunum and resulting changes in levels of gut peptide secretion. Prior work modeling this aspect of the surgery has shown that small-volume, prolonged jejunal infusions of linoleic acid (LA) produce sustained decreases in food intake and weight loss. LA infusions also significantly elevate plasma glucagon-like peptide-1 (GLP-1) levels. To assess a role for the increased circulating GLP-1 in the feeding suppression, we examined the effect of prolonged peripheral minipump administration of the GLP-1 receptor antagonist exendin 9-39 (Ex 9) on the feeding suppression produced by jejunal LA. Using a 2 × 2 design, we infused either saline or LA in the jejunum (7 h/day, 11.4 kcal) for 5 days with a subset of animals from each group receiving either saline or Ex 9 (25 pmol·kg(-1)·min(-1)) continuously via a minipump. The antagonist alone had no effect on food intake. LA reduced daily food intake greatly in excess of the kilocalories infused. Ex 9 completely blocked the feeding suppression produced by the jejunal LA infusion. Ex 9 also attenuated the increase in plasma GLP-1 induced by jejunal LA infusions. These data demonstrate that endogenous GLP-1 receptor signaling is necessary for the reduction in food intake produced by jejunal LA infusions. Whether increased secretion of additional gut peptides is also necessary for such suppressions remains to be determined.
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Affiliation(s)
- Megan J Dailey
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
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8
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Moran TH, Dailey MJ. Intestinal feedback signaling and satiety. Physiol Behav 2011; 105:77-81. [PMID: 21315751 PMCID: PMC3143258 DOI: 10.1016/j.physbeh.2011.02.005] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2010] [Revised: 01/28/2011] [Accepted: 02/01/2011] [Indexed: 01/18/2023]
Abstract
Peptidergic and neural signals arising from the presence of food in the gastrointestinal track provide feedback signals to the brain about the nature and quantity of consumed nutrients. Peptide secreting cells are differentially distributed along the gastrointestinal tract. How ingested nutrients activate or inhibit peptide secretion is complex and depends upon local, hormonal and neural mechanisms. The mode of action of the various peptides is equally complex involving endocrine, paracrine and neurocrine signaling. The success of bariatric surgical approaches to obesity treatment is secondary to alterations in gastrointestinal feedback signaling and roles of increased secretion of lower gut peptides such as peptide YY (PYY) and glucagon like peptide 1 (GLP-1) in mediating the superior effects of Roux-en-Y gastric bypass (RYGB) surgery are becoming evident. Direct nutrient delivery to jejunal sites that models the site of gastric-jejunal anastamosis in RYGB is especially effective at inhibiting food intake. Such infusions also stimulate the release of lower gut peptides suggesting a role for increased gut peptide signaling in sustaining such feeding inhibitions. Thus, gut peptides are clear targets for future obesity therapeutic developments.
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Affiliation(s)
- Timothy H Moran
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Ross 618, 720 Rutland Ave., Baltimore, MD 21205, United States.
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Matsumura S, Eguchi A, Kitabayashi N, Tanida M, Shen J, Horii Y, Nagai K, Tsuzuki S, Inoue K, Fushiki T. Effect of an intraduodenal injection of fat on the activities of the adrenal efferent sympathetic nerve and the gastric efferent parasympathetic nerve in urethane-anesthetized rats. Neurosci Res 2010; 67:236-44. [DOI: 10.1016/j.neures.2010.03.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2009] [Revised: 03/24/2010] [Accepted: 03/25/2010] [Indexed: 01/12/2023]
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Dailey MJ, Tamashiro KLK, Terrillion CE, Moran TH. Nutrient specific feeding and endocrine effects of jejunal infusions. Obesity (Silver Spring) 2010; 18:904-10. [PMID: 20134410 DOI: 10.1038/oby.2010.14] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Intestinal nutrient infusions result in variable decreases in food intake and body weight based on the nutrient type and the specific intestinal infusion site. Only intrajejunal infusions of fatty acids decrease food intake beyond the calories infused. To test whether this extra-compensatory decrease in food intake is specific to fatty acids, small volume intrajejunal infusions of glucose (Glu) and casein hydrolysate (Cas), as well as linoleic acid (LA) were administered to male Sprague-Dawley rats. Equal kilocalorie (kcal) loads of these nutrients (11.4) or vehicle were infused into the jejunum over 7 h/day for five consecutive days. Food intake was continuously monitored and body weight was measured daily. After the infusion on the final day, rats were killed and plasma collected. Intrajejunal infusions of LA and Glu, but not Cas, suppressed food intake beyond the caloric load of the infusate with no compensatory increase in food intake after the infusion period. Rats receiving LA and Glu infusions also lost significant body weight across the infusion days. Plasma glucagon-like peptide-1 (GLP-1) was increased in both the LA and Glu rats compared with control animals, with no significant change in the Cas-infused animals. Peptide YY (PYY) levels increased in response to LA and Cas infusions. These results suggest that intrajejunal infusions of LA and Glu may decrease food intake and body weight via alterations in GLP-1 signaling. Thus, particular nutrients are more effective at producing decreases in food intake, body weight, and inducing changes in peptide levels and could lead to a novel therapy for obesity.
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Affiliation(s)
- Megan J Dailey
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
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Maljaars PWJ, Peters HPF, Mela DJ, Masclee AAM. Ileal brake: a sensible food target for appetite control. A review. Physiol Behav 2008; 95:271-81. [PMID: 18692080 DOI: 10.1016/j.physbeh.2008.07.018] [Citation(s) in RCA: 304] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2007] [Revised: 07/10/2008] [Accepted: 07/14/2008] [Indexed: 12/14/2022]
Abstract
With the rising prevalence of obesity and related health problems increases, there is increased interest in the gastrointestinal system as a possible target for pharmacological or food-based approaches to weight management. Recent studies have shown that under normal physiological situations undigested nutrients can reach the ileum, and induce activation of the so-called "ileal brake", a combination of effects influencing digestive process and ingestive behaviour. The relevance of the ileal brake as a potential target for weight management is based on several findings: First, activation of the ileal brake has been shown to reduce food intake and increase satiety levels. Second, surgical procedures that increase exposure of the ileum to nutrients produce weight loss and improved glycaemic control. Third, the appetite-reducing effect of chronic ileal brake activation appears to be maintained over time. Together, this evidence suggests that activation of the ileal brake is an excellent long-term target to achieve sustainable reductions in food intake. This review addresses the role of the ileal brake in gut function, and considers the possible involvement of several peptide hormone mediators. Attention is given to the ability of macronutrients to activate the ileal brake, and particularly variation attributable to the physicochemical properties of fats. The emphasis is on implications of ileal brake stimulation on food intake and satiety, accompanied by evidence of effects on glycaemic control and weight loss.
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Affiliation(s)
- P W J Maljaars
- Division of Gastroenterology-Hepatology, Department of Internal Medicine, University Hospital Maastricht, PO box 5800 6202 AZ Maastricht, The Netherlands.
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Kemp CJ, D'Alessio DA, Scott RO, Kelm GR, Meller ST, Barrera JG, Seeley RJ, Clegg DJ, Benoit SC. Voluntary consumption of ethyl oleate reduces food intake and body weight in rats. Physiol Behav 2008; 93:912-8. [PMID: 18234242 PMCID: PMC2372161 DOI: 10.1016/j.physbeh.2007.12.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2007] [Revised: 12/13/2007] [Accepted: 12/14/2007] [Indexed: 11/15/2022]
Abstract
Previous studies have shown that administration of the fatty acids, linoleic and oleic acid, either by intragastric or intraintestinal infusion, suppresses food intake and body weight in rats. While still not fully understood, gut-mediated satiety mechanisms likely are potential effectors of this robust response to gastrointestinal fatty acid infusions. The objective of this study was to assess the effects of voluntary access to an oleic acid derivative, ethyl oleate (EO), on subsequent food intake and body weight in rats. Animals were randomized either to a 12.5% EO diet or a soybean oil diet as a "breakfast," followed either by two one-hour or one five-hour access periods to standard rodent diet, and food intake and body weights were collected. Across 14 days access, rats consuming EO on both feeding schedules gained less weight and consumed less total kilocalories than rats consuming the SO diet. Further, plasma levels of glucose and insulin were comparable in both EO and SO diet groups. In summary, EO was found to increase weight loss in rats maintained on a 75% food-restriction regimen, and attenuate weight-gain upon resumption of an ad-libitum feeding regimen. These data indicate that voluntary access to EO promoted short-term satiety, compared to SO diet, and that these effects contributed to an important and novel attenuated weight gain in EO-fed animals.
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Affiliation(s)
- Christopher J Kemp
- Department of Psychiatry, University of Cincinnati, Cincinnati, OH 45237 USA.
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13
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Warne JP, Foster MT, Horneman HF, Pecoraro NC, de Jong HK, Ginsberg AB, Akana SF, Dallman MF. The gastroduodenal branch of the common hepatic vagus regulates voluntary lard intake, fat deposition, and plasma metabolites in streptozotocin-diabetic rats. Am J Physiol Endocrinol Metab 2008; 294:E190-200. [PMID: 17971508 DOI: 10.1152/ajpendo.00336.2007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The common hepatic branch of the vagus nerve negatively regulates lard intake in rats with streptozotocin (STZ)-induced, insulin-dependent diabetes. However, this branch consists of two subbranches: the hepatic branch proper, which serves the liver, and the gastroduodenal branch, which serves the distal stomach, pancreas, and duodenum. The aim of this study was to determine whether the gastroduodenal branch specifically regulates voluntary lard intake. We performed a gastroduodenal branch vagotomy (GV) on nondiabetic, STZ-diabetic, and STZ-diabetic insulin-treated groups of rats and compared them with sham-operated counterparts. All rats had high steady-state corticosterone levels to maximize lard intake. Five days after surgery, all rats were provided with the choice of chow or lard to eat for another 5 days. STZ-diabetes resulted in a reduction in lard intake that was partially rescued by either GV or insulin treatment. Patterns of white adipose tissue (WAT) deposition differed after GV- and insulin-induced lard intake, with subcutaneous WAT increasing exclusively after the former and mesenteric WAT increasing exclusively in the latter. GV also prevented the insulin-induced reduction in the STZ-elevated plasma glucagon, triglycerides, free fatty acids, and total ketone bodies but did not alter the effect of insulin-induced reduction of plasma glucose levels. These data suggest that the gastroduodenal branch of the vagus inhibits lard intake and regulates WAT deposition and plasma metabolite levels in STZ-diabetic rats.
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Affiliation(s)
- James P Warne
- Dept. of Physiology, Box 0444, Univ. of California San Francisco, 513 Parnassus Ave., San Francisco, CA 94143, USA.
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Warne JP, Foster MT, Horneman HF, Pecoraro NC, Ginsberg AB, Akana SF, Dallman MF. Afferent signalling through the common hepatic branch of the vagus inhibits voluntary lard intake and modifies plasma metabolite levels in rats. J Physiol 2007; 583:455-67. [PMID: 17584842 PMCID: PMC2277022 DOI: 10.1113/jphysiol.2007.135996] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The common hepatic branch of the vagus nerve is a two-way highway of communication between the brain and the liver, duodenum, stomach and pancreas that regulates many aspects of food intake and metabolism. In this study, we utilized the afferent-specific neurotoxin capsaicin to examine if common hepatic vagal sensory afferents regulate lard intake. Rats implanted with a corticosterone pellet were made diabetic using streptozotocin (STZ) and a subset received steady-state exogenous insulin replacement into the superior mesenteric vein. These were compared with non-diabetic counterparts. Each group was then subdivided into those whose common hepatic branch of the vagus was treated with vehicle or capsaicin. Five days after surgery, the rats were offered the choice of chow and lard to consume for a further 5 days. The STZ-diabetic rats ate significantly less lard than the non-diabetic rats. Capsaicin treatment restored lard intake to that of the insulin-replaced, STZ-diabetic rats, but modified neither chow nor total caloric intake. This increased lard intake led to selective fat deposition into the mesenteric white adipose tissue depot, as opposed to an increase in all visceral fat pad depots evident after insulin replacement-induced lard intake. Capsaicin treatment also increased the levels of circulating glucose and triglycerides and negated the actions of insulin on these and free fatty acids and ketone bodies. Collectively, these data suggest that afferent signalling through the common hepatic branch of the vagus inhibits lard, but not chow, intake, directs fat deposition and regulates plasma metabolite levels.
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Affiliation(s)
- James P Warne
- Department of Physiology, University of California San Francisco, San Francisco, CA 94143, USA.
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Garemo M, Palsdottir V, Strandvik B. Metabolic markers in relation to nutrition and growth in healthy 4-y-old children in Sweden. Am J Clin Nutr 2006; 84:1021-6. [PMID: 17093153 DOI: 10.1093/ajcn/84.5.1021] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND The worldwide increase in overweight and obesity probably involves dietary factors, and early indicators of risk must be identified. OBJECTIVE We aimed to analyze metabolic markers in relation to dietary intake and anthropometry in healthy 4-y-old children. DESIGN A cross-sectional study of nutritional intake was performed in 95 children by use of 7-d food records. Fasting blood samples were analyzed for glucose, insulin, and lipids. RESULTS The study population was representative of Swedish children except that more parents than the average had a university education. The boys' mean energy intake was higher (6.6 +/- 0.75 MJ) than the girls' (5.7 +/- 0.79 MJ). Significant associations were found between the percentage of energy from carbohydrates and that from fat (r = -0.91) and sucrose (r = 0.59). High body mass index was associated with a low percentage of energy from fat (r = -0.32). Serum triacylglycerol, insulin, and the HOMA (homeostatic model assessment) index were higher in girls than in boys. In girls, HOMA beta-cell function was significantly negatively associated with fat intake and serum fasting insulin, and HOMA insulin resistance indexes were significantly associated with the increment in z scores for height and weight from birth to age 4 y. Compared with children with fasting insulin concentrations below the group mean + SD, the children with concentrations above that value were smaller as newborns and had larger increments in growth z scores from birth to age 4 y. CONCLUSION In healthy Swedish 4-y-olds from well-educated families, low fat intake was related to high body mass index. Upward weight and height percentile crossings were related to insulin resistance, especially in girls.
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Affiliation(s)
- Malin Garemo
- Department of Paediatrics, Institute for Clinical Sciences, Sahlgrenska Academy, Göteborg University, Göteborg, Sweden
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Randich A, Chandler PC, Mebane HC, Turnbach ME, Meller ST, Kelm GR, Cox JE. Jejunal administration of linoleic acid increases activity of neurons in the paraventricular nucleus of the hypothalamus. Am J Physiol Regul Integr Comp Physiol 2004; 286:R166-73. [PMID: 14660477 DOI: 10.1152/ajpregu.00431.2003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The present experiment examined whether neurons located in the paraventricular nucleus of the hypothalamus (PVN) respond to intestinal infusions of long-chain fatty acids. Single-unit recordings were made of neurons located in and adjacent to the PVN during jejunal administration of linoleic acid. Jejunal administration of linoleic acid increased single-unit activity of neurons located in the PVN but did not affect activity of neurons located in adjacent tissue outside the PVN. The largest increases in neuronal activity were observed in the anterior PVN (0.9-1.3 mm posterior to bregma) compared with the posterior PVN (1.8-2.1 mm posterior to bregma). Jejunal administration of saline failed to affect activity of neurons located either inside or outside the PVN. When the same neurons were subsequently tested for their response to intravenous administration of 2 microg/kg of CCK-8, excitatory responses were more frequently observed than inhibitory responses, but both types of responses were observed regardless of whether neurons were located inside or outside the PVN. In addition, there was no strong correlation between the magnitude of the neuronal response evoked by jejunal administration of linoleic acid compared with intravenous CCK-8. These data suggest that neurons located in the anterior PVN may play a role in the mediation of suppression of food intake produced by intestinal administration of lipids.
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Affiliation(s)
- Alan Randich
- Department of Psychology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
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Kreier F, Kalsbeek A, Ruiter M, Yilmaz A, Romijn JA, Sauerwein HP, Fliers E, Buijs RM. Central nervous determination of food storage—a daily switch from conservation to expenditure: implications for the metabolic syndrome. Eur J Pharmacol 2003; 480:51-65. [PMID: 14623350 DOI: 10.1016/j.ejphar.2003.08.092] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Here, we present a neuroendocrine concept to review the circularly interacting energy homeostasis system between brain and body. Body-brain interaction is circular because the brain immediately integrates an input to an output, and because part of this response may be that the brain modulates the sensitivity of this perception. First, we describe how the brain senses the body through neurons and blood-borne factors. Direct neuronal connections report the state of various organs. In addition, humoral factors are perceived by the blood-brain barrier and circumventricular organs. We describe how circulating energy carriers are sensed and what signals reach the brain during food intake, exercise and an immune response. We describe that the brain regulates the homeostatic process at two fundamentally different levels during the active and inactive states. The unbalanced output of the brain in the metabolic syndrome is discussed in relation with such circadian rhythms and with regional activity of the autonomic nervous system. In line with the above, we suggest a new approach for the diagnosis and therapy of the metabolic syndrome.
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Affiliation(s)
- Felix Kreier
- Netherlands Institute for Brain Research, 1105 AZ, Amsterdam, The Netherlands.
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Abstract
The management of diabetic gastroparesis often represents a significant clinical challenge in which the maintenance of nutrition is pivotal. Gastric emptying is delayed in 30% to 50% of patients with longstanding type 1 or type 2 diabetes and upper gastrointestinal symptoms also occur frequently. However, there is only a weak association between the presence of symptoms and delayed gastric emptying. Acute changes in blood glucose concentrations affect gastric motility in diabetes; hyperglycemia slows gastric emptying whereas hypoglycemia may accelerate it; blood glucose concentrations may also influence symptoms. It is now recognized that gastric emptying is a major determinant of postprandial glycemia and, therefore, there is considerable interest in the concept of modulating gastric emptying, by dietary or pharmacologic means, to optimize glycemic control in diabetes.
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Affiliation(s)
- Diana Gentilcore
- Department of Medicine, Royal Adelaide Hospital, North Terrace, Adelaide, South Australia 5000, Australia.
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Affiliation(s)
- W A Cupples
- Lady Davis Institute, Sir Mortimer B. Davis-Jewish General Hospital, Montreal, Quebec, Canada H3T 1E2
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