A natural mutation in Pisum sativum L. (pea) alters starch assembly and improves glucose homeostasis in humans

Elevated postprandial glucose (PPG) is a significant risk factor for non-communicable diseases globally. Currently, there is a limited understanding of how starch structures within a carbohydrate-rich food matrix interact with the gut luminal environment to control PPG. Here, we use pea seeds (Pisum sativum) and pea flour, derived from two near-identical pea genotypes (BC1/19RR and BC1/19rr) differing primarily in the type of starch accumulated, to explore the contribution of starch structure, food matrix and intestinal environment to PPG. Using stable isotope 13C-labelled pea seeds, coupled with synchronous gastric, duodenal and plasma sampling in vivo, we demonstrate that maintenance of cell structure and changes in starch morphology are closely related to lower glucose availability in the small intestine, resulting in acutely lower PPG and promotion of changes in the gut bacterial composition associated with long-term metabolic health improvements

The acute effect of food structure on post prandial glucose and subsequent metabolic responses

Glucose is a major molecule for energy supply. Thus, the movement of glucose from food into tissues is necessary for survival. However, since high levels of glucose are toxic to the body, glucose homeostasis plays a key role in preventing a number of diseases, including type 2 diabetes, obesity, coronary heart disease and many types of cancer. Empirical evidence has shown that postprandial glucose and insulin sensitivity are not only governed by the content of food but also by other factors that may play a role in the digestive process, including food structure, rheological properties and food breakdown pattern. The combination of different levels of structure—from the molecular to the micro and macro levels—develops the rheological behavior of food that impacts the availability and digestibility of nutrients. In this work, I brought together nutritional physiology and rheology to explore the impact of peas and chickpeas on postprandial glycaemia and to develop a better understanding of how their physical properties change the physiological response. This in turn will give insight into the effect of food structure and its rheological properties on postprandial metabolic responses. The main finding of this work highlighted the importance of an intact cell wall in lowering postprandial glycaemia and subsequent metabolic responses when compared to a ruptured structure. Also, this work showed that starch structure played a role in postprandial glycaemia and insulinemia when the cell wall is absent. Further investigation was performed on the rheological properties of foods with different structures, relating these results with metabolic responses. Results from studies assessing the rheological and mechanical properties of food strongly suggested that they indeed affect the food breakdown pattern during digestion. It was shown that an intact structure’s rheological properties slowed the breakdown of food during digestion. Also, different intact structures had different rheological properties that suggested an impact on the food’s behaviour during digestion and hence on postprandial metabolic responses. Throughout this thesis, an indirect relation between food structure, its rheological properties, food breakdown during digestion in relation to postprandial glycaemia and related metabolic responses was realised.Open Acces

Non-invasive diagnostic methods for non-alcoholic fatty liver disease

Background: NAFLD is one of the most common causes of liver disease worldwide. It is a spectrum of disease characterized by macrovesicular steatosis of the liver that ranges from simple fatty liver (steatosis), to non-alcoholic steatohepatitis (NASH). NASH may eventually evolve to cirrhosis and end stage complication. Liver biopsy has long been considered the gold standard of reference to diagnose NAFLD but it is costly and invasive. Recently, non-invasive methods have been proposed. Aims and methods: The aim of this study was to investigate the accuracy of non-invasive methods including (Ultrasound, computed tomography scan, Xenon-133 scan, Hepatic steatosis index, Fibroscan, NAFLD fibrosis score, APRI index, and FIB-4 index) and their combination to diagnose steatosis and to diagnose significant liver fibrosis (>F2) and cirrhosis (F4) as compared to liver biopsy. We conducted a retrospective study of 114 NASH patients (79 males, mean age 49.6±10.6). All had adequate liver histology. Results: The distribution of fibrosis stage was as follows: F0-F1= 50%, F2=16.8%, F3=19.2%, F4=14%. The distribution of steatosis grade was as follows: grade 0-1=16%, grade2=53.3%, grade3=30.7%. The following tests correlated with fibrosis: APRI index (r=0.554), FIB-4(r=0.555), NAFLD fibrosis score (r=0.473), Fibroscan(r=0.586) and Hepatic Steatosis Index (HSI) (r=0.245). The FIB-4 and APRI index showed the best diagnostic accuracy for significant fibrosis as indicated by an Area Under the Curve (AUC) of 0.801 and 0.782, respectively. The FIB-4 showed the best AUC= 0.886 for cirrhosis. None of the following tests US, CT, HSI, and xenon-133 scan were considered correlated significantly. The best combination algorithm for the detection of cirrhosis was gender and FIB-4 with an AUC of 0.8937. Conclusion: this study demonstrates that non-invasive methods for liver fibrosis are accurate to diagnose >F2 and F4. Severe steatosis cannot be reliably diagnosed by non-invasive methods. Notably, a combination of FIB-4 and gender significantly improves the performance of the single method for cirrhosis. These methods may help reducing the number of liver biopsies stratifying NASH patients that should start a screening program for HCC and esophageal varices.Contexte : La stéatose hépatique non alcoolique (SHNA) est l'une des causes les plus répandues des maladies du foie à l'échelle mondiale. Il s'agit d'un spectre de maladies qui se caractérise par une stéatose hépatique macrovésiculaire allant de la stéatose hépatique simple (stéatose) à la stéatohépatite non alcoolique (NASH). La NASH peut éventuellement évoluer vers une cirrhose et des complications en phase terminale. La biopsie du foie a longtemps été considérée comme la norme de référence par excellence pour le diagnostic de la SHNA, mais elle est coûteuse et invasive. Des méthodes non invasives ont récemment été proposées. Objectifs et méthodes : La présente étude avait pour objectif d'évaluer la précision de certaines méthodes non invasives (notamment les ultrasons [US], la tomographie par ordinateur [TO], la scintigraphie au xénon 133, l'indice de stéatose hépatique (ISH), la technique Fibroscan, le score de fibrose de SHNA, l'indice de ratio entre l'aspartate aminotransférase et les plaquettes [APRI] et l'indice FIB-4) et de l'utilisation combinée de ces méthodes pour le diagnostic de la stéatose et pour le diagnostic d'une fibrose hépatique significative (> F2) et de la cirrhose (F4), par comparaison à la biopsie du foie. Nous avons réalisé une étude rétrospective sur 114 patients atteints de NASH (79 patients de sexe masculin, âge moyen de 49,6 ans ± 10,6). Tous ces patients présentaient une histologie hépatique adéquate.Résultats : La répartition des stades de fibrose était la suivante : F0 F1 = 50 %, F2 = 16,8%, F3 = 19,2 %, F4 = 14 %. La répartition des stades de stéatose était la suivante : stade 0-1 = 16 %, stade 2 = 53,3 %, stade 3 = 30,7 %. Les tests suivants ont été mis en corrélation avec la fibrose : l'indice APRI (r = 0,554), l'indice FIB-4 (r = 0,555), le score de fibrose de SHNA (r = 0,473), la technique Fibroscan (r = 0,586) et l'indice de stéatose hépatique (r = 0,245). L'indice FIB-4 et l'indice APRI ont offert la meilleure précision diagnostique en ce qui concerne la fibrose significative, comme l'indiquent la surface sous la courbe (SSC) de 0,801 et la SSC de 0,782 respectivement. L'indice FIB-4 a présenté la meilleure SSC, soit 0,886, pour ce qui est de la cirrhose. Aucun des tests suivants, c'est à dire les tests aux US, la TO, l'ISH, et la scintigraphie au xénon 133, n'était considéré comme étant corrélé significativement. Le meilleur algorithme de combinaison pour le dépistage de la cirrhose était le sexe et l'indice FIB-4 avec une surface sous la courbe de 0,8937. Conclusion: cette étude démontre que les méthodes non invasives de diagnostic de la fibrose hépatique sont précises en ce qui concerne les stades > F2 et F4. La Stéatose sévère ne peut être diagnostiqué de façon fiable par des méthodes non invasives Notamment, une combinaison de l'indice FIB-4 et du sexe améliore considérablement le rendement de la méthode unique en ce qui a trait à la cirrhose. Ces méthodes pourraient aider à réduire le nombre de biopsies du foie visant à stratifier les patients atteints de NASH qui devraient entreprendre un programme de dépistage du carcinome hépatocellulaire (CHC) et des varices œsophagiennes

Nonalcoholic fatty liver disease: Noninvasive methods of diagnosing hepatic steatosis

Hepatic steatosis is the buildup of lipids within hepatocytes. It is the simplest stage in nonalcoholic fatty liver disease (NAFLD). It occurs in approximately 30% of the general population and as much as 90% of the obese population in the United States. It may progress to nonalcoholic steatohepatitis, which is a state of hepatocellular inflammation and damage in response to the accumulated fat. Liver biopsy remains the gold standard tool to diagnose and stage NAFLD. However, it comes with the risk of complications ranging from simple pain to life-threatening bleeding. It is also associated with sampling error. For these reasons, a variety of noninvasive radiological markers, including ultrasound, computed tomography, magnetic resonance spectroscopy, and the controlled attenuation parameter using transient elastography and Xenon-133 scan have been proposed to increase our ability to diagnose NAFLD, hence avoiding liver biopsy. The aim of this review is to discuss the utility and accuracy of using available noninvasive diagnostic modalities for fatty liver in NAFLD

Prognostic Value of Non-Invasive Fibrosis and Steatosis Tools, Hepatic Venous Pressure Gradient (HVPG) and Histology in Nonalcoholic Steatohepatitis.

Non-invasive diagnostic methods for liver fibrosis predict clinical outcomes in viral hepatitis and nonalcoholic fatty liver disease (NAFLD). We specifically evaluated prognostic value of non-invasive fibrosis methods in nonalcoholic steatohepatitis (NASH) against hepatic venous pressure gradient (HVPG) and liver histology.This was a retrospective cohort study of 148 consecutive patients who met the following criteria: transjugular liver biopsy with HVPG measurement; biopsy-proven NASH; absence of decompensation; AST-to-Platelets Ratio Index (APRI), fibrosis-4 (FIB-4), NAFLD fibrosis score, ultrasound, hepatic steatosis index and Xenon-133 scan available within 6 months from biopsy; a minimum follow-up of 1 year. Outcomes were defined by death, liver transplantation, cirrhosis complications. Kaplan-Meier and Cox regression analyses were employed to estimate incidence and predictors of outcomes, respectively. Prognostic value was expressed as area under the curve (AUC).During a median follow-up of 5 years (interquartile range 3-8), 16.2% developed outcomes, including 7.4% who died or underwent liver transplantation. After adjustment for age, sex, diabetes, the following fibrosis tools predicted outcomes: HVPG >10mmHg (HR=9.60; 95% confidence interval [CI] 3.07-30.12), histologic fibrosis F3-F4 (HR=3.14; 1.41-6.95), APRI >1.5 (HR=5.02; 1.6-15.7), FIB-4 >3.25 (HR=6.33; 1.98-20.2), NAFLD fibrosis score >0.676 (HR=11.9; 3.79-37.4). Prognostic value was as follows: histologic fibrosis stage, AUC=0.85 (95% CI 0.76-0.93); HVPG, AUC=0.81 (0.70-0.91); APRI, AUC=0.89 (0.82-0.96); FIB-4, AUC=0.89 (0.83-0.95); NAFLD fibrosis score, AUC=0.79 (0.69-0.91). Neither histologic steatosis nor non-invasive steatosis methods predicted outcomes (AUC<0.50).Non-invasive methods for liver fibrosis predict outcomes of patients with NASH. They could be used for serial monitoring, risk stratification and targeted interventions

Impact of chickpea hummus on postprandial blood glucose, insulin and gut hormones in healthy humans combined with mechanistic studies of food structure, rheology and digestion kinetics

Slowing the rate of carbohydrate digestion leads to low postprandial glucose and insulin responses, which are associated with reduced risk of type 2 diabetes. There is increasing evidence that food structure plays a crucial role in influencing the bioaccessibility and digestion kinetics of macronutrients. The aims of this study were to compare the effects of two hummus meals, with different degrees of cell wall integrity, on postprandial metabolic responses in relation to the microstructural and rheological characteristics of the meals. A randomised crossover trial in 15 healthy participants was designed to compare the acute effect of 27 g of starch, provided as hummus made from either intact chickpea cells (ICC) or ruptured chickpea cells (RCC), on postprandial metabolic responses. In vitro starch digestibility, microstructural and rheological experiments were also conducted to evaluate differences between the two chickpea hummus meals. Blood insulin and GIP concentrations were significantly lower (P &lt; 0.02, P &lt; 0.03) after the consumption of the ICC meal than the meal containing RCC. In vitro starch digestion for 90 min was slower in ICC than in RCC. Microscopic examination of hummus samples digested in vitro for 90 min revealed more intact chickpea cells in ICC compared to the RCC sample. Rheological experiments showed that fracture for ICC hummus samples occurred at smaller strains compared to RCC samples. However, the storage modulus for ICC was higher than RCC, which may be explained by the presence of intact cells in ICC. Food structure can affect the rate and extent of starch bioaccessibility and digestion and may explain the difference in the time course of metabolic responses between meals. The rheological properties were measured on the two types of meals before ingestion, showing significant differences that may point to different breakdown mechanisms during subsequent digestion. This trial was registered at clinicaltrial.gov as NCT03424187.</p

Flow chart displaying selection of study participants for analysis.

<p>Out of 289 patients with biopsy proven NASH by transjugular liver biopsy, 32 were excluded for inadequate biopsy specimen. After further exclusion of patients with missing data, those with anti-HCV or HBsAg positivity, patients with significant alcohol intake, the ones with decompensated cirrhosis at entry and patients with insufficient follow-up, the remaining sample of 148 consecutive patients with NASH was included in the present study.</p

Survival curves of probability of clinical outcomes by: (A) APRI fibrosis category; (B) FIB-4 fibrosis category; (C) NAFLD fibrosis score category.

<p>Survival curves of probability of clinical outcomes by: (A) APRI fibrosis category; (B) FIB-4 fibrosis category; (C) NAFLD fibrosis score category.</p

Demographic, clinical and histological characteristics of 148 patients with NASH at baseline and comparison of those with and without clinical outcomes.

<p>Legend: Results given as mean ± SD or n (%). BMI, body mass index. IU, international units; ALT, alanine aminotransferase; AST, aspartate aminotransferase; γGT, gamma-glutamyl transpeptidase; Hb1Ac, hemoglobin glycosylated; HVPG, hepatic venous pressure gradient; APRI, AST-to-Platelet Ratio; NAFLD, nonalcoholic fatty liver disease; HSI, hepatic steatosis index. The p-values refer to T-test or chi-square test between patients with clinical outcomes and those without clinical outcomes.</p><p>Demographic, clinical and histological characteristics of 148 patients with NASH at baseline and comparison of those with and without clinical outcomes.</p

AUC of HVPG, histologic fibrosis stage, APRI, FIB-4 and NAFLD fibrosis score for prediction of clinical outcomes.

<p>AUC of HVPG, histologic fibrosis stage, APRI, FIB-4 and NAFLD fibrosis score for prediction of clinical outcomes.</p