The contribution of human milk (HM) microbiota to infant gut health was addressed by evaluating the impact of HM bacteria, combined in two synthetic communities (SynComs) exhibiting anti-inflammatory (AI) or high immunomodulatory (HI) properties in vitro, on gut immune and barrier functions, and microbiota. Neonatal mini-piglets were fed either a formula without supplementation (CTRL) or supplemented with AI or HI SynComs and were compared to sow milk-fed (SM) piglets over a period of 24 days. Feces were collected on postnatal day (PND) 8, and ileal, colonic, and fecal samples were collected on PND24. The multifactorial analysis indicated that the two HM-derived SynComs impacted microbiota and intestinal functions differently. Several genera, mainly belonging to Bacillota, displayed different relative abundances between the formula-fed groups at both PND8 and PND24. At PND8, the fecal secretory IgA (sIgA) level in HI piglets was slightly lower than in SM piglets but markedly higher than in CTRL and AI piglets. SynComs HI and/or AI slightly increased the expression of genes involved in pro-inflammatory (IL6, TNFaR1), antioxidant (SOD2), anti-inflammatory (SOCS3), and Treg (FOXP3) pathways in ileal and colonic tissues compared with the CTRL group. Systemic immune functions were also modulated with a cytokine secretion capacity of peripheral blood mononuclear cells that tended to be higher with HI supplementation. Interestingly, SynCom bacteria were correlated with several ileal and colonic genera, and both were correlated with physiological variables. Overall, our findings support the influence of HM bacteria, provided in formulas as SynCom at a physiological concentration, on gut microbiota and functions.IMPORTANCEEarly-life environmental factors, such as neonatal diet, influence the gut microbiota, which plays a key role in the functional development of the gut. However, the role of the human milk (HM) microbiota, particularly with regard to the immunomodulatory properties of HM bacteria, is not well understood. This study investigates the differential effects of two synthetic communities with a similar taxonomic composition representative of the taxonomic diversity of the HM microbiota. These communities exhibit contrasting immunomodulatory properties that were previously characterized using an in vitro intestinal quadricellular model. Daily supplementation with these two SynComs modulated the composition of the gut microbiota and the gut physiology differently, particularly the intestinal immune signatures. In conclusion, the functional profile of bacteria within the HM microbiota may induce distinct developmental profiles of gut physiology in infants.

Electroacupuncture (EA), a modern adaptation of traditional acupuncture, is increasingly used to treat various conditions, including gastrointestinal disorders, although its mechanisms remain debated. Previous work in healthy minipigs showed that acute EA modulates gut–brain axis activity, with notable effects on brain responses. This study examined the effects of chronic EA on brain function, physiology, and behavior in obese minipigs.Sixteen adult Yucatan minipigs were fed a high-fat/high-sucrose diet for two months, then assigned to either a control group (n=8) or a chronic EA group (n=8), which received 12 sessions of 20-minute EA targeting Sanwan/Dafengmen acupoints. Brain activity was assessed using BOLD fMRI during acute EA (before and after diet) and oral sucrose stimulation (after treatment). Behavioral tests, blood sampling, and post-mortem gene expression analyses across four brain regions were also conducted.Acute EA modulated cortical-limbic-striatal circuits differently in normal-weight versus obese animals. Chronic EA altered brain responses to sucrose in regions involved in cognitive control, reward, decision-making, and memory (p<0.05). Gene expression analyses revealed region-specific effects on 15 genes related to blood–brain barrier integrity, inflammation, neurotransmission, synaptic plasticity, and metabolism. Following return to a normal diet, both groups lost weight, but only EA-treated animals showed greater reductions in adiposity (p<0.001) and plasma free fatty acids (p=0.028). Differences in dopamine and tryptophan levels were also observed (p<0.05).These findings demonstrate that chronic EA modulates brain function and metabolic pathways in obese minipigs, supporting its potential role in treating obesity and related disorders.

Excessive consumption of high-fat, high-sugar diets promotes obesity, metabolic syndrome, and chronic inflammation through increased fat accumulation. While adopting a balanced diet promotes weight loss and improvements in various physiological parameters, persistent alterations in microbiota composition and function, metabolic imbalances, and behavioral changes may increase vulnerability to ethanol consumption and preference. In this context, the present study aims to investigate how switching from a high-sugar, high-saturated fat diet (HSB) to a standard diet (AIN93G) affects: (I) cecal microbiota composition and function, (II) colonic homeostasis, and (III) vulnerability to voluntary ethanol consumption in mice. To conduct the study, six animals were maintained on the standard diet, while 12 were given the HSB diet for 8 weeks. After this period, the HSB mice were switched to AIN93G for 4 weeks, with one subgroup given access exclusively to water (SWITCH) and another to water or a 10% ethanol solution (SWITCH+EtOH). The evaluation included measurements of body weight, adiposity index, cecal microbial composition, metabolomic profile, gut and hepatic morphology, transcriptional regulation of genes involved in colonic homeostasis and striatal dopaminergic neurotransmission, as well as ethanol consumption and preference. The results indicate that switching to the standard diet does not completely reverse obesity-induced alterations. Persistent cecal dysbiosis, metabolic imbalances, and dopaminergic sensitization increase the predisposition to compulsive alcohol consumption and perpetuate epithelial and hepatic dysfunction. Therefore, post-obesity interventions should combine weight management with strategies to restore microbiota and intestinal barrier function, along with measures to reduce vulnerability to reinforcement-seeking behaviors.

Dietary protein reduces energy intake in following meals by signaling directly or indirectly to the brain. We recently observed differences in plasma amino acid kinetics and intra-gastric behavior between micellar casein (MC) and sodium caseinate (SC) in pigs, two factors that impact food intake. Our objective was to clarify whether the supramolecular structure of casein, given as a preload to pigs, impacts on subsequent food intake. Overnight fasted pigs were allowed to consume casein drinks differing in casein macromolecular structure (SC vs MC) within 5 min in a cross-over study. Ad libitum intake of their regular feed was assessed during 1 h, either 1 or 4 h after casein drink ingestion. To evaluate the potential mechanisms at play, gastric emptying of the casein drinks radiolabeled with 99Tc-colloïd was followed using gamma-scintigraphy while plasma kinetics of ghrelin, GLP-1, insulin and free amino acids were evaluated. The amount of feed consumed 1, but not 4 h, after SC ingestion was lower than the amount of feed consumed after MC ingestion (P = 0.03). Gastric emptying parameters, plasma ghrelin, GLP-1 and insulin kinetics after both types of casein ingestion were not significantly different (P > 0.05). However, plasma free amino acid concentrations, known to reduce food intake, increased after both SC and MC ingestion but was greater after SC than MC ingestion from 60 to 120 min (P = 0.009). In conclusion, casein supramolecular structure in a preload drink impacts differently subsequent energy intake, likely due to difference in amino acid bioavailability. Micellar casein exhibits less anorectic effect than sodium caseinate, a property that could benefit population with high protein need but low appetite such as elderly.

Background: Infant formulas (IFs), the only adequate substitute to human milk, are complex matrices that require numerous ingredients and processing steps that may impact protein digestion and subsequent amino acid (AA) absorption. Objectives: The objective was to understand the impact of the protein ingredient quality within IFs on postprandial plasma AA pro fi les. Methods: Four isonitrogenous and isocaloric IFs were produced at a semi-industrial scale using whey proteins from different origins (cheese compared with ideal whey) and denaturation levels (IF-A,-B,-C), and caseins with different supramolecular organizations (IF-C,-D). Ten Yucatan minipiglets (12- to 27-d-old) were used as a human infant model and received each IF for 3 d according to a Williams Latin square followed by a 2-d wash-out period. Jugular plasma was regularly sampled from 10 min preprandial to 4 h postprandial on the third day to measure free AAs, urea, insulin, and glucose concentrations. Data were statistically analyzed using a mixed linear model with diet (IFs), time, and sex as fi xed factors and piglet as random factor. Results: IFs made with cheese whey (IF-A and-B) elicited signi fi cantly higher plasma total and essential AA concentrations than IFs made with ideal whey (IF-C and-D), regardless of the preand postprandial times. Most of the differences observed postprandially were explained by AA homeostasis modi fi cations. IFs based on cheese whey induced an increased plasma concentration of Thr due to both a higher Thr content in these IFs and a Thr-limiting degrading capability in piglets. The use of a nonmicellar casein ingredient led to reduced plasma content of AA catabolism markers (IF-D compared with IF-C). Conclusions: Overall, our results highlight the importance of the protein ingredient quality (composition and structure) within IFs on neonatal plasma AA pro fi les, which may further impact infant protein metabolism.

Despite the WHO recommendations in favor of breastfeeding, most infants receive infant formulas (IFs), which are complex matrices involving numerous ingredients and processing steps. Our aim was to understand the impact of the quality of the protein ingredient in IFs on gut microbiota and physiology, blood metabolites and brain gene expression. Three IFs were produced using whey proteins (WPs) from cheese whey (IF-A) or ideal whey (IFs-C and -D) and caseins, either in a micellar form (IFs-A and -C) or partly in a non-micellar form (IF-D). Twenty-four Yucatan minipiglets received one of the IFs from 2- to 21-days of age. The piglets were then euthanized 84 min postprandially. Blood, ileal and colonic digesta and tissues, the liver and the hypothalamus were sampled. Gut microbiota composition and activity, the expression of intestinal and brain genes involved in barrier, immune, endocrine, nutrient carrier and neuronal functions and serum metabolite levels were determined. Intestinal paracellular permeability was assessed with an ex vivo Ussing chamber. The data were analyzed using multifactorial and univariate analyses. The colon was the main site to be physiologically affected by the quality of the dairy protein ingredients used in IFs. Colonic paracellular permeability was significantly higher in IF-D-fed piglets than in those receiving IFs-A and -C, in line with the expression of genes encoding tight junction proteins (OCLN, CLDN3 and CLDN4). IF-D up-regulated the colonic expression of genes involved in the immune function (SOCS3, PIGR and TNFα) when compared to IF-A. Although intestinal α- and β-diversities did not significantly differ among IFs, some specific differences were observed, such as the abundances of Campylobacterota phylum and Bacteroides genera and fecal butyrate production, which were increased with IFs-C and -D versus IF-A. The kynurenine pathway was favored in piglets fed IF-D compared to IF-A, based on colonic gene expression and serum metabolites. In addition, levels of some serum metabolites, particularly putrescine, spermidine and spermine, were higher in piglets fed IF-D than IFs-A and -C. Overall, IF-D, which combined ideal WPs and some non-micellar caseins, appeared to differ most from IF-A in terms of its physiological consequences, suggesting that both WP and casein ingredient quality may mediate the physiological properties of IFs, probably through changes to the colonic microbiota composition and activity.

We aimed to assess if casein structure affects its digestion and its subsequent amino acid delivery kinetic. Higher nitrogen levels were recovered in dialysates after in vitro digestions of sodium caseinate (SC, formed of small aggregates) compared to micellar casein (MC, native form of casein) and calcium caseinate (CC, intermediate structure). Likewise, plasma indispensable amino-acid concentration peak was higher after SC compared to MC or CC ingestion in healthy volunteers in a randomized, double blind, cross-over study. In pigs, gamma-scintigraphy using labelled meals revealed that SC was mainly localized in the proximal part of the stomach whereas MC was distributed in the whole gastric cavity. Caseins were found in both solid and liquid phases and partly hydrolyzed casein in the solid phase shortly after SC drink ingestion. These data support the concept of slow (MC) and rapid (SC) casein depending of casein structure, likely due to their intra-gastric clotting properties.

La dénutrition peut se développer chez des patients obèses souffrant d'une maladie aiguë ou chronique ou après chirurgie de l'obésité. Celle-ci favorise l'apparition d'une obésité sarcopénique définie en partie par une perte de masse musculaire. Une meilleure compréhension de cette physiopathologie justifie le développement de nouveaux modèles expérimentaux. L'objectif est de caractériser les effets de la dénutrition sur le phénotype du muscle squelettique dans notre nouveau modèle de mini-porc Yucatan (Lacaze et al., 2022, Clin Nutr) cette fois rendu obèse. Seize mini-porcs Yucatan âgés de 30 mois ont été rendus obèses à l'aide d'un régime high fat high sucrose (HF/HS) durant 8 semaines. À l'issue de cette période (T0), les animaux ont été répartis en 3 groupes soumis à des régimes différents durant 8 semaines : un régime standard (OB-ST, n = 5) ou hypocalorique–normoprotéique (OB-HN, n = 5) ou hypocalorique–hypoprotéique (OB-HH, n = 6). La composition corporelle des mini-porcs a été évaluée par scanner au début (T0) et à la fin des 8 semaines de dénutrition (T1). Des biopsies du muscle trapèze ont été effectuées en fin de protocole à T1. Afin de nous assurer de l'effet obésogène du régime HF/HS, nous avons également comparé les animaux OB-ST à un groupe de mini-porcs sains âgés de 30 mois ayant été soumis à un régime standard (ST, n = 5) durant 16 semaines. La 1re partie de l'étude visait à comparer les mini-porcs du groupe OB-ST à ceux du groupe ST. Le groupe OB-ST présentait un poids corporel et des surfaces musculaire et de tissu adipeux viscéral plus élevés que le groupe ST (+39,1 %, p = 0,02, +24,9 %, p = 0,008 et +192,0 %, p = 0,03, respectivement). Une hypertrophie musculaire du trapèze était observée chez les mini-porcs rendus obèses comparés aux mini-porcs sains. Cette hypertrophie se caractérisait par une augmentation de la surface de section transversale (CSA) des fibres, tout particulièrement celles de type II. Après normalisation en fonction du poids corporel des animaux, cette valeur était cependant inférieure dans le groupe OB-ST comparé au groupe ST (−19,3 %, p = 0,001). La seconde partie de l'étude visait à étudier les effets de deux régimes de dénutrition sur les mini-porcs Yucatan obèses. Les analyses réalisées à T0 et T1 démontraient une diminution du poids corporel, des surfaces de tissu adipeux viscéral et musculaire chez les animaux OB-HH après 8 semaines de régime (−9,8 %, p = 0,03, −41,5 %, p = 0,03 et −6,49 %, p = 0,03 respectivement). Les animaux OB-HN avaient tendance à la diminution de leur poids corporel et de leur surface de tissu adipeux viscéral sans changement significatif de leur surface musculaire. Le poids corporel des mini-porcs OB-ST tendait à augmenter entre T0 et T1 sans changement significatif de leur composition corporelle. L'analyse histologique du trapèze démontrait que la CSA des fibres était significativement plus faible chez les mini-porcs OB-HH et OB-HN que chez les mini-porcs OB-ST (−33,9 %, p < 0,001 et −19,1 %, p = 0,004 respectivement). Cependant, cette atrophie musculaire était majorée dans le groupe OB-HH comparé au groupe OB-HN et pouvait s'expliquer par une diminution de la surface des fibres de type II dans les groupes dénutris. Les animaux soumis à un régime HF/HS de 8 semaines présentent une masse musculaire insuffisante au regard de leur prise de poids corporel en accord avec ce qui est observé chez des patients obèses. Les deux groupes d'animaux dénutris présentent une atrophie musculaire, tout particulièrement des fibres de type II, avec une majoration de ce phénomène dans le groupe soumis au régime HH. Notre modèle apparaît ainsi reproduire le phénotype clinique et musculaire de la dénutrition observée chez des patients obèses souffrant d'une maladie aiguë ou chronique ou après chirurgie de l'obésité. Les voies de signalisation impliquées dans l'anabolisme et le catabolisme musculaire sont actuellement en cours d'analyses dans le muscle trapèze.

Background & aims: In most cases, Roux-en-Y gastric bypass (RYGBP) is an efficient intervention to lose weight, change eating behavior and improve metabolic outcomes in obese patients. We hypothesized that weight loss induced by RYGBP in obese Yucatan minipigs would induce specific modifications of the gut-brain axis and neurocognitive responses to oral sucrose stimulation in relationship with food intake control.Methods: An integrative study was performed after SHAM (n 1/4 8) or RYGBP (n 1/4 8) surgery to disentangle the physiological, metabolic and neurocognitive mechanisms of RYGBP. BOLD fMRI responses to sucrose stimulations at different concentrations, brain mRNA expression, cecal microbiota, and plasma metabolomics were explored 4 months after surgery and integrated with WGCNA analysis.Results: We showed that weight loss induced by RYGBP or SHAM modulated differently the frontostriatal responses to oral sucrose stimulation, suggesting a different hedonic treatment and inhibitory control related to palatable food after RYGBP. The expression of brain genes involved in the serotoninergic and cannabinoid systems were impacted by RYGBP. Cecal microbiota was deeply modified and many metabolite features were differentially increased in RYGBP. Data integration with WGCNA identified interactions between key drivers of OTUs and metabolites features linked to RYGBP.Conclusion: This longitudinal study in the obese minipig model illustrates with a systemic and integrative analysis the mid-term consequences of RYGBP on brain mRNA expression, cecal microbiota and plasma metabolites. We confirmed the impact of RYGBP on functional brain responses related to food reward, hedonic evaluation and inhibitory control, which are key factors for the success of anti-obesity therapy and weight loss maintenance.(c) 2023 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Rationale: Malnutrition or sarcopenic obesity may occur in obese patients. Aim: to characterize the skeletal muscle phenotype in a new model of malnutrition (1) in obese Yucatan minipigs. Methods: 30-month-old Yucatan minipigs (n=16) were made obese by a High Fat High Sucrose diet for 8 weeks. Then (T0), obese animals were submitted to a standard diet (OB-ST, n=5) or a low-calorie low-protein (LCLP) diet (OB-LCLP, n=6) for additional 8 weeks (T1). Body composition was assessed by CT-Scan at T0 and T1. Trapezius muscle biopsies were taken at T1. The OB-ST group was compared to a group of 30-month-old healthy minipigs fed with a standard diet (ST, n=5) for 16 weeks. Results: The OB-ST group had higher body weight (+37.7%, p=0.03), muscle (+24.9%, p=0.02), and visceral fat (+192.0%, p=0.03) areas than the ST-group. Trapezius CSA normalized to body weight was lower in OB-ST group (-25.2%, p<0.001). Type II and I fibers CSA were respectively higher (+18.5, p<0.001) and lower (-17.6%, p<0.001) in OB-ST vs. ST groups. No significant change was observed concerning the protein turnover markers despite an increase of REDD1 in the OB-ST group (+96.4%, p=0.02). At T1 vs. T0, body weight (-9,8%, p=0.03), muscle (-6.5%, p=0.03) and visceral fat (-41,5%, p=0.03) areas decreased in OB-LCLP group. Trapezius fiber CSA (-6.7%, p<0.001) and type II fibers CSA (-14.6%, p<0.001) were significantly lower in OB-LCLP vs. OB-ST group. Ubiquitinated proteins were higher expressed in OB-LCLP than OB-ST groups (+38.3%, p=0.02). Conclusion: The lower muscle fiber area (normalized by weight) of OB-ST animals mimics what is observed in obese patients. Malnourished minipigs reported type II muscle fiber atrophy, probably in relation to an increase of protein degradation. Our Yucatan minipig model reproduces the clinical and muscular phenotype of malnutrition and sarcopenic obesity. References: (1) Lacaze L et al. Clin Nutr 2022;41:2077-86 Disclosure of Interest: None declared

BACKGROUND & AIMS:Malnutrition can develop in patients with obesity suffering from acute or chronic illness or after obesity surgery, promoting sarcopenic obesity. A better understanding of this pathophysiology and the development of new therapeutics for chronic diseases, that are often complicated with malnutrition and obesity, justify the development of new animal experimental models close to the human physiology. This study aims to characterize the effects of obesity and underfeeding on Yucatan obese minipigs, assessing its validity as a preclinical model for obesity-related malnutrition. METHODS:Sixteen 30-month-old Yucatan minipigs were divided into two groups for 8 weeks: a standard diet group (ST, n = 5) and an obesogenic diet group (OB, n = 11). After 8 weeks, the OB group was further divided into two sub-groups: a standard diet group (OB-ST, n = 5) and a low-calorie/low-protein diet group (OB-LC/LP, n = 6) for 8 weeks. Body composition by CT-Scan and blood parameters were monitored, and trapezius muscle biopsies were collected to analyse signaling pathways involved in protein turnover and energy metabolism. RESULTS:At W8, OB-ST animals exhibited significantly higher body weight (+37.7%, p = 0.03), muscle mass (+24.9%, p = 0.02), and visceral fat (+192.0%, p = 0.03) compared to ST. Trapezius cross sectional area (CSA) normalized to body weight was lower in OB-ST animals (-15.02%, p = 0.017). At W16, no significant changes were observed in protein turnover markers, although REDD1 increased in OB-ST (96.4%, p = 0.02). After 8 weeks of low-caloric/low protein diet, OB-LC/LP showed decreased body weight (-9.8%, p = 0.03), muscle mass (-6.5%, p = 0.03), and visceral fat (-41.5%, p = 0.03) compared to OB-ST animals. Trapezius fiber CSA significantly decreased in OB-LC/LP (-36.1%, p < 0.0001) and normalized to body weight (-25.4%, p < 0.0001), combined to higher ubiquitinated protein content (+38.3%, p = 0.02). CONCLUSION:Our data support that the Yucatan minipig model mimics nutritional and skeletal muscle phenotypes observed in obese patients, with or without protein-energy malnutrition. It also reproduces muscle atrophy observed in chronic diseases or post-obesity surgery, making it a promising preclinical model for obesity-related malnutrition.

This study aimed to compare the gut-brain axis responses to acute electroacupuncture (EA) at different acupoint combinations in the minipig model. Four adult Yucatan minipigs were subjected twice to four acute EA treatments (25-minute acute sessions) including sham (false acupoints) and control (no EA), during anesthesia and according to a Latin-square design paradigm. Acupoint combinations (4 loci each) are head-abdomen (#70 Dafengmen, #35 Sanwan), back (bilateral #27 Pishu, #28 Weishu), leg (bilateral #79 Hangou, #63 Housanli), and sham (2 bilateral points that are not acupoints). Electrocardiograms were performed to explore heart rate variability (HRV). Infrared thermography was used to measure skin temperature at the stimulation points. Saliva (cortisol) and blood samples (leptin, total/active ghrelin, insulin, and glucose) were collected for further analyses before and after acute EA. All animals were also subjected to BOLD fMRI to investigate the brain responses to EA. Acute EA significantly modulated several physiological and metabolic parameters compared to basal, sham, and/or control conditions, with contrasting effects in terms of BOLD responses in brain regions involved in the hedonic and cognitive control of food intake. The head-abdomen combination appeared to be the most promising combination in terms of brain modulation of the corticostriatal circuit, with upregulation of the dorsolateral prefrontal cortex, dorsal striatum, and anterior cingulate cortex. It also induced significantly lower plasma ghrelin levels compared to sham, suggesting anorectic effects, as well as no temperature drop at the stimulation site. This study opens the way to a further preclinical trial aimed at investigating chronic EA in obese minipigs.

Background & aims: Severe malnutrition exposes patients to adverse outcomes and a higher mortality risk. The Yucatan minipig, closer to human physiology than murine models could be a pertinent and innovative experimental model for studying the physiopathology and consequences of severe malnu-trition. The present study aimed to determine whether a low calorie/low protein diet (LC/LP) can reproduce marasmus malnutrition in minipigs, and to characterize body composition, gut microbiota, malnutrition-related blood parameters, and histological and molecular skeletal muscle patterns. Methods: Eleven Yucatan minipigs were subjected to two different diets: a standard control diet (ST) (n = 5) and a LC/LP diet (n = 6). LC/LP animals daily received 50% of an isocaloric low-protein diet (10.37 MJ/kg, 8.6% protein). Body composition was measured by computed tomography (CT-scan) before (T0) and after 8 weeks of diet (T8). Trapezius and biceps femoris muscles were sampled at the end of protocol to perform histological and molecular analyses. Gut microbiota composition were was also analyzed at T0 and T8 in fecal samples. Results: Eight weeks of LC/LP diet significantly reduced body weight (-12.3 & PLUSMN; 9.5%, P = 0.03) and gut microbiota richness (i.e. number of observed species) (-10.4 & PLUSMN; 8.3%, P = 0.014) compared to baseline. After 8 weeks, LC/LP animals exhibited a significant reduction of retroperitoneal fat and skeletal muscle surface areas (P = 0.03 and P = 0.047, respectively), whereas these parameters remained unchanged in ST animals. These reductions were associated with lower muscle fiber cross-sectional area (CSA) in trapezius (P < 0.001) and biceps femoris (P = 0.003) in LC/LP animals compared to ST. LC/LP diet promoted an increase of AMP kinase phosphorylation in trapezius and biceps femoris (P = 0.05), but did not affect cytochrome c and COX IV protein content, markers of mitochondrial content. Gene and proteins involved in ubiquitin-proteasome system and apoptosis remained unchanged after 8 weeks of LC/LP diet both in trapezius and biceps femoris. Conclusion: All these findings support that this experimental minipig model of severe malnutrition is valid to mimic pathophysiological changes occurring in human protein-energy marasmus malnutrition and muscle atrophy associated with malnutrition, as observed in patients with secondary sarcopenia.(C) 2022 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Performing the Roux-en-Y gastric bypass (RYGBP) in obese Yucatan minipigs provides an opportunity to explore the mechanisms behind the effects of this surgery in controlled environmental and nutritional conditions. We hypothesized that RYGBP in these minipigs would induce changes at multiple levels, as in obese humans. We sought to characterize RYGBP in a diet-induced obese minipig model, compared with a pair-fed sham group. After inducing obesity with an ad libitum high-fat/high-sugar diet, we performed RYGBP (n = 7) or sham surgery (n = 6). Oral glucose tolerance tests (OGTT) were performed before and after surgery. Histological analyses were conducted to compare the alimentary limb at sacrifice with tissue sampled during RYGBP surgery. One death occurred in the RYGBP group at postoperative day (POD) 3. Before sacrifice, weight loss was the same across groups. GLP-1 secretion (OGTT) was significantly higher at 15, 30 and 60 min at POD 7, and at 30 and 60 min at POD 30 in the RYGBP group. Incremental insulin area under the curve increased significantly after RYGBP (p = 0.02). RYGBP induced extensive remodeling of the alimentary limb. Results show that RYGBP can be safely performed in obese minipigs, and changes mimic those observed in humans.

Changes in microglial development and morphology can be induced by inflammatory conditions and associated with eating or mood disorders, such as hyperphagia or depression. In a previous paper in the minipig model, we showed that maternal Western diet during gestation and lactation decreased hippocampus neurogenesis and food-rewarded cognitive abilities in the progeny. Whether these alterations are concomitant with a central inflammatory process in brain structures involved in learning and memory (hippocampus, HPC), cognitive (prefrontal cortex, PFC), or hedonic (orbitofrontal cortex, OFC) control of food intake is still unknown. In the present study, Yucatan minipigs (Sus scrofa) sows were exposed to two different diets during gestation and lactation (standard, SD N = 7 vs. Western diet, WD N = 9). Iba1 is a calcium-binding protein specifically expressed in microglia in the brain, which plays an important role in the regulation of the microglia function. Iba1 expression was examined by immunohistochemical analyses in the PFC, OFC and HPC of piglets. The density of microglial cells, as well as their morphology, were assessed in order to have an indirect insight of microglial cell activation state possibly in relationship with neuroinflammation. The density of Iba1-positive cells was higher in the PFC but not in the HPC of WD compared to SD piglets (p < 0.001). In the HPC, anterior and dorsolateral PFC, WD piglets had more unipolar cells, contrary to SD that had more multipolar cells (P < 0.0001). Opposite effects were observed in the OFC, with SD presenting more unipolar (P < 0.001) microglial cells compared to WD. We showed here that maternal diet during pregnancy and lactation had significant effects on morphological changes of microglial cells in the offspring, and that these effects differed between the HPC and PFC, suggesting different response mechanisms to the early nutritional environment.

Psychological chronic stress is an important risk factor for major depressive disorder, of which consequences have been widely studied in rodent models. This work aimed at describing a pig model of chronic stress based on social isolation, environmental impoverishment and unpredictability. Three groups of animals of both sexes were constituted. Two were exposed to the psychosocial stressors while receiving (SF, n = 12) or not (SC, n = 22) the antidepressant fluoxetine, and a third group (NSC, n = 22) remained unstressed. Animals were observed in home pens and during dedicated tests to assess resignation and anxiety-like behaviors. Brain structure and function were evaluated via proton MRS and fMRI. Hippocampal molecular biology and immunodetection of cellular proliferation (Ki67+) and neuron maturation (DCX+) in the dentate gyrus were also performed. Salivary cortisol, fecal short-chain fatty acids (SCFAs), and various plasmatic and intestinal biomarkers were analyzed. Compared to NSC, SC animals showed more resignation (p = 0.019) and had a higher level of salivary cortisol (p = 0.020). SC brain responses to stimulation by a novel odor were lower, similarly to their hippocampal neuronal density (p = 0.015), cellular proliferation (p = 0.030), and hippocampal levels of BDNF and 5-HT1AR (p = 0.056 and p = 0.007, respectively). However, the number of DCX+ cells was higher in the ventral dentate gyrus in this group (p = 0.025). In addition, HOMA-IR was also higher (p < 0.001) and microbiota fermentation activity was lower (SCFAs, SC/NSC: p < 0.01) in SC animals. Fluoxetine partially or totally reversed several of these effects. Exposure to psychosocial stressors in the pig model induced effects consistent with the human and rodent literature, including resignation behavior and alterations of the HPA axis and hippocampus. This model opens the way to innovative translational research exploring the mechanisms of chronic stress and testing intervention strategies with good face validity related to human.

L’axe intestin-cerveau est un des acteurs principaux de la régulation du comportement alimentaire après chirurgie bariatrique. Le bypass gastrique avec anse en Y de Roux (RYGBP) est l’intervention qui a le plus démontré son efficacité à court et long terme sur la perte de poids et la résolution des comorbidités liées à l’obésité morbide. Afin de préparer la réalisation d’une étude originale visant à évaluer les corrélations entre les patterns neurocomportementaux en réponse à la chirurgie et les différents phénotypes intestinaux, nous avons mis au point un modèle de RYGBP chez le miniporcs obèse. Après une période de 6 semaines d’un régime obésogène (hypercalorique enrichi en lipides et en sucres) un RYGBP (n = 7) ou une intervention « sham » (n = 6) ont été réalisés chez des miniporcs Yucatan obèses (poids moyen 82,6 kg ± 2,8). Le protocole de suivi et de réalimentation était identique dans les deux groupes avec une reprise progressive basée sur la tolérance alimentaire des animaux dans le groupe RYGBP après chirurgie. Afin d’apprécier l’effet du RYGBP sur les incrétines, une charge orale de glucose (équivalent de 1 g/kg de glucose) a été réalisée en préopératoire, à 7 jours et à 1 mois après la chirurgie. Les concentrations plasmatiques de GLP-1 ont été dosées via un cathéter central avant la charge orale puis à 15, 30, 60, 120 et 180 minutes. Les résultats des comparaisons multiples ont été analysés avec une ANOVA à mesures répétées et correction de Bonferroni. Treize miniporcs obèses ont été opérés, 7 RYGBP et 6 « sham ». Dans le groupe RYGBP, 1 décès brutal sur sepsis a été constaté à j3 et une sténose de l’anastomose gastro-jéjunale a limité la prise alimentaire. Par ailleurs, les suites postopératoires ont été simples pour les autres animaux. À 1 mois, le pourcentage de perte de poids moyen était significativement supérieur dans le groupe RYGBP comparé au « sham » (−15 ± 3 vs −12 ± 2 %, p = 0,049). A une semaine de la chirurgie, la concentration plasmatique de GLP-1 après charge orale en glucose à 15, 30, 60 et 120 min était significativement augmentée (p < 0,01) en comparaison avec le groupe sham (p. ex à 30 min 29,85 ± 4,31 vs 6,67 ± 1,73 pM, p < 0,01). À 1 mois, la sécrétion de GLP-1 était aussi significativement augmentée dans le groupe RYGBP par rapport au groupe « sham » à 15, 30 et 60 minutes. La réalisation d’un RYGBP chez le miniporc Yucatan obèse a entraîné une perte de poids significative et une augmentation significative de la sécrétion de GLP-1 comme observé chez les patients obèses opérés d’un RYGBP. Ces résultats nous permettent de valider notre modèle de RYGBP chez le miniporc obèse pour la réalisation d’expérimentations focalisées sur l’axe intestin-cerveau.

Gastric emptying of food is mainly driven by the caloric concentration, the rheological properties of the chyme, and the physical state (liquid/solid) of food once in the stomach. The present work investigated: (1) The effect of the composition and the viscosity of drinkable yogurts on gastric emptying in pigs, and (2) the behavior of yogurts during dynamic in vitro digestion. Three isocaloric liquid yogurts were manufactured: Two enriched in protein and fiber showing either a low (LV) or high (HV) viscosity, one control enriched in sugar and starch (CT). They were labelled with 99mTc-sulfur colloid and given to pigs (n = 11) to determine gastric emptying pattern by gamma scintigraphy. Then dynamic in vitro digestion of the yogurts was done using the parameters of gastric emptying determined in vivo. Gastric emptying half-times were significantly longer for LV than CT, whereas HV exhibited an intermediate behavior. In vitro gastric digestion showed a quick hydrolysis of caseins, whereas whey proteins were more resistant in the stomach particularly for LV and HV. During the intestinal phase, both whey proteins and caseins were almost fully hydrolyzed. Viscosity was shown to affect the behavior of yogurt in the small intestine.