Temporal Patterns of Glucagon and Its Relationships with Glucose and Insulin following Ingestion of Different Classes of Macronutrients

Background: glucagon secretion and inhibition should be mainly determined by glucose and insulin levels, but the relative relevance of each factor is not clarified, especially following ingestion of different macronutrients. We aimed to investigate the associations between plasma glucagon, glucose, and insulin after ingestion of single macronutrients or mixed-meal. Methods: thirty-six participants underwent four metabolic tests, based on administration of glucose, protein, fat, or mixed-meal. Glucagon, glucose, insulin, and C-peptide were measured at fasting and for 300 min following food ingestion. We analyzed relationships between time samples of glucagon, glucose, and insulin in each individual, as well as between suprabasal area-under-the-curve of the same variables (ΔAUCGLUCA, ΔAUCGLU, ΔAUCINS) over the whole participants’ cohort. Results: in individuals, time samples of glucagon and glucose were related in only 26 cases (18 direct, 8 inverse relationships), whereas relationship with insulin was more frequent (60 and 5, p < 0.0001). The frequency of significant relationships was different among tests, especially for direct relationships (p ≤ 0.006). In the whole cohort, ΔAUCGLUCA was weakly related to ΔAUCGLU (p ≤ 0.02), but not to ΔAUCINS, though basal insulin secretion emerged as possible covariate. Conclusions: glucose and insulin are not general and exclusive determinants of glucagon secretion/inhibition after mixed-meal or macronutrients ingestion.

Developmental Stage, Solid Food Introduction and Suckling Cessation Differentially Influence the Co-maturation of the Gut Microbiota and Intestinal Epithelium in Rabbits

Background In mammals, the establishment around weaning of a symbiotic relationship between the gut microbiota and its host determines long-term health. Objective The aim of this study was to identify the factors driving the co-maturation of the gut microbiota and intestinal epithelium at the suckling-to-weaning transition. We hypothesized that developmental stage, solid food ingestion and suckling cessation contribute to this process. Methods From birth to day 18, Hyplus rabbits were exclusively suckling. From day 18 to day 25, rabbits were i) exclusively suckling or ii) suckling and ingesting solid food or iii) exclusively ingesting solid food. The microbiota (16S amplicon sequencing), metabolome (nuclear magnetic resonance) and epithelial gene expression (high-throughput qPCR) were analyzed in the caecum at day 18 and 25. Results The microbiota structure and metabolic activity were modified with age when rabbits remained exclusively suckling. The epithelial gene expression of nutrient transporters, proliferation markers and innate immune factors were also regulated with age (e.g., 1.5-fold decrease of TLR5). Solid food ingestion by suckling rabbits had a major effect on the gut microbiota by increasing its α-diversity, remodeling its structure (e.g., 6.3-fold increase of Ruminococcaceae) and metabolic activity (e.g., 4.6-fold increase of butyrate). Solid food introduction also regulated the gene expression of nutrient transporters, differentiation markers and innate immune factors in the epithelium (e.g., 3-fold increase of NOS2). Suckling cessation had no effect on the microbiota while it regulated the expression of genes involved in epithelial differentiation and immunoglobulin transport (e.g., 2.5-increase of PIGR). Conclusion In rabbits, the maturation of the microbiota at the suckling-to-weaning transition is driven by the introduction of solid food and to a lesser extent by developmental stage. In contrast, the maturation of the intestinal epithelium at the suckling-to-weaning transition is under the influence of developmental stage, solid food introduction and suckling cessation.

Feasibility of a low FODMAPs diet without initial dietician intervention in the management of patients with irritable bowel syndrome: a prospective study

Background and aims: Efficiency of a low FODMAPs diet (LFD) to relieve symptoms in patients with irritable bowel syndrome (IBS) has been proved in several studies. Our study aimed to evaluate the management of IBS-patients when explanations about LFD are given by the physician without dietician intervention. Patients and methods: Patients with IBS were evaluated prospectively after explanations about the LFD were given with the help of a leaflet. A first questionnaire evaluating trigger foods and diet acceptability was submitted to the patient after the consultation. Six weeks later, a second questionnaire evaluated patient’s understanding and adherence to the diet, the evolution of symptoms, and the need for a specific dietetic support. Results: Thirty-five patients were included (69% female; mean age 45±15). Seventy-four percent of the patients thought that their symptoms were related to food ingestion, and 97% were ready to go on a diet to improve their symptoms. During the second visit, 91% of the patients reported understanding correctly the explanations, 52% followed LFD regularly, 28% sometimes and 20% did not follow LFD at all or barely. Multiple non-adherence factors were reported. All symptoms, except constipation, decreased significantly six weeks after starting LFD. Finally, 77% of the patients reported satisfaction with care and 69% were willing to be supported by a dietician. Conclusions: Most IBS patients understood explanations given by GI physicians, but low compliance to the diet and a wish for dietician support was highlighted, suggesting that a dietician intervention should be scheduled when LFD is implemented.

Exercise-induced anaphylaxis unrelated to food ingestion and with hyperleukotrieneuria during challenge testing

Background Exercise-induced anaphylaxis (EIA) is a rare and potentially life-threatening disorder that can develop independently without food ingestion. Cold drinks can also trigger symptoms in some patients with cold-induced anaphylaxis. We present a case of a patient with EIA that was diagnosed on the basis of positive exercise loading test with hyperleukotrieneuria. Case presentation A 12-year-old girl presented with acute flushing, cyanosis, swollen eyelids, and dyspnea after an endurance run in winter or swimming in a cold-water pool. She also developed dyspnea after having a cold drink. She had no history of food allergies, atopy, or asthma. No association was noted between anaphylaxis and food intake in her history. On the first day, she ingested 200 mL of 5 °C cold water in 30 s, which did not trigger symptomatic responses, but her urinary leukotriene E4 (LTE4) level increased (pre-challenge test: 295 pg/mg-creatinine (cr), post-challenge test: 400 pg/mg-cr). On the second day, she underwent the exercise loading test according to the Bruce protocol by using an ergometer to increase the power of exercise every 2 min. She had been fasting for > 15 h and did not have breakfast. Just after the exercise loading test, the plasma adrenaline and noradrenaline increased. At 15 min after the exercise loading test, her plasma adrenaline and histamine (pre-challenge test: 0.7 ng/mL, 15 min post-challenge test: 81 ng/mL) rose sharply with anaphylaxis symptoms accompanied by increasing urinary LTE4 (pre-challenge test: 579 pg/mg-cr, post-challenge test: 846 pg/mg-cr). After she was discharged, she was restricted from strenuous exercise especially in cold environments and prescribed an adrenaline autoinjector. Conclusion Cold stimulation can become a co-effector of EIA. Measurements of urinary LTE4 levels during challenge testing are useful for diagnosing EIA and capture the pre-anaphylaxis stage.

Medicinal Plants, Phytochemicals, and Their Impacts on the Maturation of the Gastrointestinal Tract

The gastrointestinal tract (GIT) is the first point of contact for ingested substances and thus represents a direct interface with the external environment. Apart from food processing, this interface plays a significant role in immunity and contributes to the wellbeing of individuals through the brain-gut-microbiota axis. The transition of life from the in utero environment, to suckling and subsequent weaning has to be matched by phased development and maturation of the GIT; from an amniotic fluid occupancy during gestation, to the milk in the suckling state and ultimately solid food ingestion at weaning. This phased maturation of the GIT can be affected by intrinsic and extrinsic factors, including diet. Despite the increasing dietary inclusion of medicinal plants and phytochemicals for health benefits, a dearth of studies addresses their impact on gut maturation. In this review we focus on some recent findings mainly on the positive impact of medicinal plants and phytochemicals in inducing precocious maturation of the GIT, not only in humans but in pertinent animals. We also discuss Paneth cells as mediators and potential markers of GIT maturation.

Simultaneous quantification of trimethylamine N-oxide, trimethylamine, choline, betaine, creatinine, and propionyl-, acetyl-, and l-carnitine in clinical and food samples using HILIC-LC-MS

Trimethylamine-N-oxide (TMAO), a microbiome-derived metabolite from the metabolism of choline, betaine, and carnitines, is associated to adverse cardiovascular outcomes. A method suitable for routine quantification of TMAO and its precursors (trimethylamine (TMA), choline, betaine, creatinine, and propionyl-, acetyl-, and l-carnitine) in clinical and food samples has been developed based on LC-MS. TMA was successfully derivatized using iodoacetonitrile, and no cross-reactions with TMAO or the other methylamines were detected. Extraction from clinical samples (plasma and urine) was performed after protein precipitation using acetonitrile:methanol. For food samples (meatballs and eggs), water extraction was shown to be sufficient, but acid hydrolysis was required to release bound choline before extraction. Baseline separation of the methylamines was achieved using a neutral HILIC column and a mobile phase consisting of 25 mmol/L ammonium formate in water:ACN (30:70). Quantification was performed by MS using external calibration and isotopic labelled internal standards. The assay proved suitable for both clinical and food samples and was linear from ≈ 0.1 up to 200 μmol/L for all methylamines except for TMA and TMAO, which were linear up to 100 μmol/L. Recoveries were 91–107% in clinical samples and 76–98% in food samples. The interday (n=8, four duplicate analysis) CVs were below 9% for all metabolites in clinical and food samples. The method was applied successfully to determine the methylamine concentrations in plasma and urine from the subjects participating in an intervention trial (n=10) to determine the effect of animal food ingestion on methylamine concentrations. Graphical abstract

Postprandial fasting related headache during Ramadan in Saudi Arabia: A cross-sectional study

Background Headache disorders are classified as primary or secondary; however, among the secondary headaches, those attributed to food ingestion are not well understood. Therefore, we conducted this study to describe and characterize a new headache entity that occurred during the holy month of Ramadan. This headache occurred within 4 h of breaking the fast. Methods This is a nationwide descriptive community-based cross-sectional study conducted during the last 10 days of Ramadan, based on a random sample of adults living in Saudi Arabia. The demographic data, headache symptomatology, nature and distribution of the pain, possible triggering and relieving factors, and patient management programs were analyzed. Results Completed questionnaires were obtained from 16,031 participants. Of those, 3147 (19.6%) reported headaches after breaking the fast in Ramadan. In 84.1% of cases, there was no previous diagnosis of headache or migraine. The characteristics of these postprandial fasting-related headaches mostly was episodic in nature (72%). The nature of the headache was variable, mostly heaviness or tightness (53.9%). Triggering factors included ingestion of fried food in (45%) and coffee (26.3%). Lying down and sleeping was found to be an important relieving factor (61%). Conclusion A new headache entity is being described. Appears to be quite common, occurs less than 2 h following the first meal, and is mostly of the heaviness and tension type.

Characteristics of the Peritrophic Matrix of the Silkworm, Bombyx mori and Factors Influencing Its Formation

The peritrophic matrix (PM) secreted by the midgut cells of insects is formed by the binding of PM proteins to chitin fibrils. The PM envelops the food bolus, serving as a barrier between the content of the midgut lumen and its epithelium, and plays a protective role for epithelial cells against mechanical damage, pathogens, toxins, and other harmful substances. However, few studies have investigated the characteristics and synthesis factors of the PM in the silkworm, Bombyx mori. Here, we examined the characteristics of the PM in the silkworms. The PM thickness of the silkworms increased gradually during growth, while there was no significant difference in thickness along the entire PM region. Permeability of the PM decreased gradually from the anterior to posterior PM. We also found that PM synthesis was affected by food ingestion and the gut microbiota. Our results are beneficial for future studies regarding the function of the PM in silkworms.