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Hypomagnesemia is defined as serum [Mg2+] < 1.7 mg/dL. The prevalence of hypomagnesemia in outpatient and hospitalized patient population is 6–12 %. The incidence of hypomagnesemia is approximately 65 %. The causes of hypomagnesemia fall into four major categories: (1) decreased intake of Mg2+; (2) decreased intestinal absorption; (3) increased urinary losses; and (4) drugs. In addition to these causes, transcellular transport of Mg2+ into the cell is caused by infusion of glucose or epinephrine.

The aim of this study was to develop an in vitro drug permeability methodology which mimics the gastrointestinal environment more accurately than conventional 2D methodologies through a three-dimensional (3D) Caco-2 tubules using a microphysiological system. Such a system offers significant advantages, including accelerated cellular polarization and more accurate mimicry of the in vivo environment. This methodology was confirmed by measuring the permeability of propranolol as a model compound, and subsequently applied to those of solifenacin and bile acids for a comprehensive understanding of permeability for the drug product in the human gastrointestinal tract. To protect the Caco-2 tubules from bile acid toxicity, a mucus layer was applied on the surface of Caco-2 tubules and it enables to use simulated intestinal fluid. The assessment using propranolol reproduced results equivalent to those obtained from conventional methodology, while that using solifenacin indicated fluctuations in the permeability of solifenacin due to various factors, including interaction with bile acids. We therefore suggest that this model will serve as an alternative testing system for measuring drug absorption in an environment closely resembling that of the human gastrointestinal tract.

Objective To investigate the effect and the mechanism of Astragalus membranaceus (Huangqi in Chinese, HQ) extract on the intestinal absorption of six alkaloids of Aconitum carmichaelii (Fuzi in Chinese, FZ) in rats with spleen deficiency and provide novel insights into the application of HQ on modulating intestinal barrier. Methods Four-week-old male Sprague-Dawley rats were fed with Xiaochengqi Decoction to induce the spleen deficiency model for 40 d. Single-pass intestinal perfusion model were used to study the effects of HQ extract on the absorption of alkaloids. Protein expression and mRNA levels of MRP2 and BCRP and tight junction proteins (TJ, including Claudin-1, Occludin and ZO-1) were measured using Western blot and real-time PCR, respectively. The location and expression of TJ protein was also investigated by the immunofluorescence method. Results Compared with the normal group, the protein expression of MRP2, BCRP and TJ proteins in the model group were significantly down-regulated. After oral administration of HQ, the alkaloid absorption in intestinal villi was inhibited, MRP2, BCRP and TJ proteins were up-regulated, the green fluorescence staining of Claudin-1, Occludin, and ZO-1 was enhanced, and a thick layer of mucus was deposited on the surface of the epithelium of the intestinal cavity. Conclusion HQ as an intestinal barrier modulator improves the physiological changes of the intestinal environment of spleen deficiency to reduce the absorption of toxic components, leading to a decrease in the absorption of drug-like molecules.

Efflux transport systems are essential to suppress the absorption of xenobiotics from the intestinal lumen and protect the critical tissues at the blood-tissue barriers, such as the blood–brain barrier. The function of drug efflux transport is dominated by various transporters. Accumulated clinical evidences have revealed that genetic variations of the transporters, together with coadministered drugs, affect the expression and/or function of transporters and subsequently the pharmacokinetics of substrate drugs. Thus, in the preclinical stage of drug development, quantitative prediction of the impact of efflux transporters as well as that of uptake transporters and metabolic enzymes on the pharmacokinetics of drugs in humans has been performed using various in vitro experimental tools. Various kinds of human-derived cell systems can be applied to the precise prediction of drug transport in humans. Mathematical modeling consisting of each intrinsic metabolic or transport process enables us to understand the disposition of drugs both at the organ level and at the level of the whole body by integrating a variety of experimental results into model parameters. This review focuses on the role of efflux transporters in the intestinal absorption and brain distribution of drugs, in addition to recent advances in predictive tools and methodologies.

Azithromycin is an antibiotic listed in the essential list of medicines for adults and pediatrics. Conflicting evidence has been found regarding azithromycin classification according to the Biopharmaceutics classification system (BCS). The purpose of this study was to identify the critical variables that influence the oral absorption of azithromycin in adults and pediatrics.Azithromycin solubility and dissolution studies (oral suspension) were performed in buffers and biorelevant media simulating the fasted and fed gastrointestinal tract. A PBPK model was developed for azithromycin for healthy adult volunteers and pediatrics (Simcyp® v18.2) informed by in vitro solubility and dissolution studies to predict drug performance after administration of azithromycin as an oral suspension.The developed PBPK model predicted azithromycin plasma concentrations-time profiles after administration of an oral suspension to adults and pediatrics. Sensitivity analysis of solubility vs dose suggests that absorption is independent of solubility within the therapeutic dose range in both adults and pediatrics. The developed PBPK model for adults and pediatrics was consistent with the mechanism of permeation through the intestinal membrane (passive and active processes) being the rate-limiting step of azithromycin's absorption.The physiologically based approach proposed was shown to be useful to determine the factors controlling drug absorption in adults and pediatrics.

Vitamin E has eight different naturally occurring forms: four tocopherols and four tocotrienols. Because α-tocopherol has three asymmetric carbons, both natural α-tocopherol (RRR-α-tocopherol) and synthetic α-tocopherol (all-rac-α-tocopherol) are utilized in both pharmaceutical products and food additives. Therefore, determining the distribution of vitamin E in the body is very important. With regard to absorption, and transportation of vitamin E, it is suggested that the pathways mediated by three proteins (CD36, SR-BI, and NPC1L1) as well as passive diffusion affect absorption of vitamin E. Vitamin E homologs are mainly transported by very low−density lipoprotein (VLDL) with the α-tocopherol being recognized by the α-tocopherol transfer protein in liver. However, it is also suggested that chylomicrons (CMs) and high-density lipoprotein (HDL) are involved in transportation of vitamin E homologs from the small intestine to each section of peripheral tissue. In particular, it is speculated that vitamin E homologs transportation by CMs and HDL from enterocytes to peripheral tissues such as adipose tissue greatly affects the distribution of vitamin E homologs, excluding α-tocopherol. However, how lipoprotein lipase affects the incorporation of vitamin E homologs containing lipoprotein into peripheral tissues is unclear. Whether there is biodiscrimination when vitamin E homologs are incorporated into peripheral tissues from lipoprotein is an interesting question. It is likely that future research will reveal how individual vitamin E homologs are incorporated into peripheral tissue, especially the brain, adipose tissue, and skin.

Calcium plays a key role in skeletal mineralization and several intracellular and extracellular homeostatic networks. It is an essential element that is only available to the body through dietary sources. Daily acquisition of calcium depends, in addition to the actual intake, on the hormonally regulated state of calcium homeostasis through three main mechanisms: bone turnover, intestinal absorption, and renal reabsorption. These procedures are regulated by a group of interacting circulating hormones and their key receptors. This includes parathyroid hormone (PTH), PTH-related peptide, 1,25-dihydroxyvitamin D, calcitonin, fibroblast growth factor 23, the prevailing calcium concentration itself, the calcium-sensing receptor, as well as local processes in the bones, gut, and kidneys.

Direct-acting oral anticoagulants (DOACs) vary in bioavailability and sites of absorption in the gastrointestinal tract (GIT). Data on DOAC use after major GIT surgery are limited. The aim of this case series was to report the impact of surgical resection or bypass of the GIT on rivaroxaban and apixaban peak plasma concentrations. This was a case series of patients who received rivaroxaban or apixaban after GIT surgery, during the period of July 1, 2019, to December 31, 2020. Peak plasma concentrations of rivaroxaban and apixaban were assessed for the expected concentrations. Of the 27 assessed patients, 18 (66.7%) received rivaroxaban, and 9 (33.3%) received apixaban. After rivaroxaban therapy, 4 of 5 patients (80%) who underwent gastrectomy, and 3 of 3 patients (100%) who underwent duodenum and proximal jejunum exclusion had peak plasma concentrations of rivaroxaban lower than the effective range, whereas 11 of 11 patients (100%) who underwent distal bowel or ileostomy had peak rivaroxaban plasma within the effective range. After apixaban therapy, 5 of 6 patients (83.3%) who underwent total or partial gastrectomy achieved effective peak concentrations. All the patients who underwent proximal and distal bowel resection or bypass had peak concentrations of apixaban within the effective range. In conclusion, surgical resection or bypass of the upper GIT could affect DOAC absorption and subsequently peak plasma concentrations. This effect was more observed among rivaroxaban recipients. An injectable anticoagulant or vitamin K antagonist may be preferred if DOAC concentrations cannot be measured after GIT surgery.

Objetive To evaluate the enterohepatic circulation of 75-Selenium turoselecolic acid (75Se-SeHCAT) during the first 3 h and its correlation with the abdominal retention at the 7th day (AR7), as contribution to the clinical study of biliar acid malabsorption (BAM). Materials and methods 38 patients with chronic diarrhea were retrospectively studied. Acquisition protocol included static abdominal images at 1st, 2nd and 3rd hour and the 7th day after oral administration of the radiopharmaceutical. Images of 1–3 h determined 5 patterns of enterohepatic circulation that, due to their location, were characterized as: 1) gallbladder 2−3 h, 2) gallbladder 3 h, 3) gallbladder-abdomen 2−3 h, 4) abdomen, 5) upper left abdomen. The association of these patterns with the AR7 (Fisher, STATA) were investigated. Patients were classified as Non BAM (AR7 > 15%), mild-BAM (AR7 15−10%), moderate-BAM (AR7 10−5%) or severe-BAM (AR7 Results 19 patients had an AR7 diagnostic of BAM (7 mild-BAM, 5 moderate-BAM, 7 severe-BAM). The pattern “gallbladder at 2−3 h” was statistically associated with Non BAM (p 0,008), while “gallbladder-abdomen at 2−3 h” was correlated with having BAM (p 0,029). Conclusion Variations detected at the abdominal level in images during the first 3 h were associated with changes in intestinal absorption and the incorporation of the radiopharmaceutical into the pool of bile acids, so visual interpretation of the images at 2nd and 3rd hour could be useful in the final assessment of the study.

Lycopene is well known as an efficient natural antioxidant; however, its hydrophobic structure limits intestinal absorption through the epithelium by conventional food. Oil-based edibles containing tomato increase the bioavailability of lycopene; therefore, the preparation of emulsions emerged as a solution to prepare lycopene supplements. This work reports the preparation of a composite with lycopene and layered double hydroxides (LDH) nanoparticles. Four LDH compositions were studied of which MgAl–Cl, MgAl–CO3, ZnAl–Cl and ZnAl–CO3, were their combinations. Hydrodynamic size and zeta potential were measured in aqueous suspensions for all the composites. Lycopene maintains its antioxidant capability within the magnesium-based composites and it is synergized in the zinc-containing LDHs. The improved hydrodispersability of the composites allowed us to assess the antioxidant capacity and the oxidative stress protection in conventional aqueous assays, which are limited for traditional oily lycopene formulations. The cation composition of the LDH influenced the antioxidant capacity; however, those containing magnesium presented a non-toxic performance in the oxidative stress assays. The obtained composites demonstrated to be an alternative to design lycopene aqueous formulations or increase its bioavailability.

Back ground: PCOS is the commonest endocrinopathy among women of reproductive age. Its worldwide prevalence has been estimated between5-10%. Rotterdam criteria is known to be the most important in such patients.Vitamin D, a fat-soluble vitamin, can be produced in two ways: by intestinal absorption and endogenous synthesis from a precursor of 17-hydroxyl cholesterol on the skin with sufficient exposure to ultraviolet sunlight. Most references consider a serum 25(OH) vitamin D of < 20 ng/ml as vitamin D deficiency. Aim of the work: The aim of this work is assessment of the level of vitamin D in female have polycystic ovary syndrome & healthy female. Patient and methods: This is a case control study held in Misr Al-Gadeda Military Hospital in gynecology outpatient clinic from May 2020 - May 2021.Patients selected from attendees of the outpatient gynecological clinic and inpatient gynecological ward at Misr Al-Gadeda Military Hospital. Group A: 45 women diagnosed with PCO based on Rotterdam Criteria 2003. Group B: 45 fertile women without PCOS . Results: The results indicated that 25(OH) vitamin D was significantly lower in PCOS group than in control group. There were no significant correlations between 25(OH) vitamin D and age and BMI. Conclusion: PCOS is known to be one of the commonest endocrine problems between female of the reproductive age.25 (OH) Vitamin-D was significantly lower in PCOS group than in the control group.No significant difference was found in Vitamin D level related to age group and body mass index.

Eicosapentaenoic acid (EPA) from freeze-dried biomass of Nannochloropsis oceanica microalgae resists ruminal biohydrogenation in vitro, but in vivo demonstration is needed. Therefore, the present study was designed to test the rumen protective effects of N. oceanica in lambs. Twenty-eight lambs were assigned to one of four diets: Control (C); and C diets supplemented with: 1.2% Nannochloropsis sp. oil (O); 12.3% spray-dried N. oceanica (SD); or 9.2% N. oceanica (FD), to achieve 3 g EPA /kg dry matter. Lambs were slaughtered after 3 weeks and digestive contents and ruminal wall samples were collected. EPA concentration in the rumen of lambs fed FD was about 50% higher than lambs fed SD or O diets. Nevertheless, the high levels of EPA in cecum and faeces of animals fed N. oceanica biomass, independently of the drying method, suggests that EPA was not completely released and absorbed in the small intestine. Furthermore, supplementation with EPA sources also affected the ruminal biohydrogenation of C18 fatty acids, mitigating the shift from the t10 biohydrogenation pathways to the t11 pathways compared to the Control diet. Overall, our results demonstrate that FD N. oceanica biomass is a natural rumen-protected source of EPA to ruminants.

Key points Significant differences in intestinal lipid absorption and lymphatic transport were found between female and male animals. Estrogen treatment significantly reduced [3 H]-triacylglycerol (TAG) lymphatic output through suppressing TAG transport in ovariectomized (OVX) rats, and this effect is associated with enhanced vegfa gene expression in the intestine. Progesterone treatment significantly decreased the output of [14 C]-cholesterol (Chol) in lymph by inhibiting Chol absorption in the OVX rats. Estrogen treatment also increased lymphatic output of apolipoprotein A-I (apoA-I) in the OVX rats, which may contribute to the reduced risk of atherosclerosis in females. Abstract Although the basic process of intestinal lipid absorption and transport is understood, many critical aspects remain unclear. One question, in particular, is whether intestinal lipid absorption and transport differ between the sexes. Using a well-established lymph fistula model, we found that intact female mice exhibited lower lymphatic output of triacylglycerol (TAG) than male mice. Further analysis revealed that the female mice segregated into two groups: the high group having similar lymphatic TAG transport to the males, and the low group having significantly less lymphatic output, implying the impact of cyclical variation of ovarian hormonal levels. These led us to examine whether estradiol (E2) and progesterone (P) affect intestinal absorption and lymphatic transport of dietary lipids. In ovariectomized (OVX) rats, E2 treatment significantly reduced [3 H]-TAG lymphatic output through reducing TAG transport; and P-treatment decreased [14 C]-cholesterol (Chol) lymphatic output by inhibiting Chol absorption, compared to vehicle treatment. Gene expression data suggested that E2 enhances vascular endothelial growth factor-A (VEGF-A) signaling to reduce the permeability of lacteals, leading to reduced CM transport through the lymphatic system. Interestingly, E2 treatment also increased lymphatic output of apolipoprotein A-I (apoA-I), but not apoB-48 and apoA-IV, in the OVX rats. Collectively, these data suggested that ovarian hormone-induced reductions of intestinal lipid absorption and lymphatic transport, as well as increased lymphatic output of apoA-I, may contribute to a beneficial protection from atherosclerosis in females. This article is protected by copyright. All rights reserved.

Linerixibat, an oral small molecule ileal bile acid transporter inhibitor under development for cholestatic pruritus in primary biliary cholangitis, was designed for minimal intestinal absorption (site of pharmacological action). This study characterized the pharmacokinetics, absorption, distribution, metabolism, and excretion of [14C]-linerixibat in humans following an intravenous microtracer, concomitant with unlabeled oral tablets, and [14C]-linerixibat oral solution. Linerixibat exhibited absorption-limited flip-flop kinetics: longer oral versus intravenous half-life (6-7 h vs 0.8 h). The short intravenous half-life was consistent with high systemic clearance (61.9 L/h) and low volume of distribution (16.3 L). In vitro studies predicted rapid hepatic clearance via cytochrome P450 (CYP) 3A4 metabolism, which deceptively predicted human hepatic clearance within 1.5-fold. However, linerixibat was minimally metabolized in humans after intravenous administration: ~80% elimination via biliary/fecal excretion (>90-97% as unchanged parent) and ~20% renal elimination by glomerular filtration (>97% as unchanged parent). Absolute oral bioavailability of linerixibat was exceedingly low (0.05%), primarily due to a very low fraction absorbed (0.167%; fgut~100%), with high hepatic extraction ratio (77.0%) acting as a secondary barrier to systemic exposure. Oral linerixibat was almost entirely excreted (>99% recovered radioactivity) in feces as unchanged and unabsorbed linerixibat. Consistent with the low oral fraction absorbed and ~20% renal recovery of intravenous [14C]-linerixibat, urinary elimination of orally administered radioactivity was negligible (

Oral formulations of insulin are typically designed to improve its intestinal absorption and increase its blood bioavailability. Here we show that polymerized ursodeoxycholic acid, selected from a panel of bile-acid polymers and formulated into nanoparticles for the oral delivery of insulin, restored blood-glucose levels in mice and pigs with established type 1 diabetes. The nanoparticles functioned as a protective insulin carrier and as a high-avidity bile-acid-receptor agonist, increased the intestinal absorption of insulin, polarized intestinal macrophages towards the M2 phenotype, and preferentially accumulated in the pancreas of the mice, binding to the islet-cell bile-acid membrane receptor TGR5 with high avidity and activating the secretion of glucagon-like peptide and of endogenous insulin. In the mice, the nanoparticles also reversed inflammation, restored metabolic functions and extended animal survival. When encapsulating rapamycin, they delayed the onset of diabetes in mice with chemically induced pancreatic inflammation. The metabolic and immunomodulatory functions of ingestible bile-acid-polymer nanocarriers may offer translational opportunities for the prevention and treatment of type 1 diabetes.

Background: When it comes to barrier and pore creation in metazoans, especially vertebrates and tunicates. Claudins are an important family of transmembrane proteins. In epithelia and endothelia's apical junctional complex, chordate claudins are crucial architectural proteins for tight junction strands. Psoriasis patients often have some degree of subclinical intestinal irritation. In gastrointestinal mucosal biopsies, lymphocytic infiltration is found in about 60% of patients. Intestinal absorption is hampered by structural and functional changes in the colon caused by inflammatory cells. Those who have psoriasis have abnormalities in fecal fat excretion, decreased D-xylose absorption, and impaired lactase activity. Objective: To assess the relation between CLAUDIN-3 protein with dermatological diseases. Conclusion: Claudin-3 is a key component of tight junctions, which may serve as marker of gut barrier integrity. Claudin-3 level may be altered in patients with psoriasis.

Berberine (BBR) is an isoquinoline alkaloid extracted from Coptis chinensis that improves diabetes, hyperlipidemia and inflammation. Due to the low oral bioavailability of BBR, its mechanism of action is closely related to the gut microbiota. This study focused on the CYP51 enzyme of intestinal bacteria to elucidate a new mechanism of BBR transformation by demethylation in the gut microbiota through multiple analytical techniques. First, the docking of BBR and CYP51 was performed; then, the pharmacokinetics of BBR was determined in ICR mice in vivo, and the metabolism of BBR in the liver, kidney, gut microbiota and single bacterial strains was examined in vitro. Moreover, 16S rRNA analysis of ICR mouse feces indicated the relationship between BBR and the gut microbiota. Finally, recombinant E. coli containing cyp51 gene was constructed and the CYP51 enzyme lysate was induced to express. The metabolic characteristics of BBR were analyzed in the CYP51 enzyme lysate system. The results showed that CYP51 in the gut microbiota could bind stably with BBR, and the addition of voriconazole (a specific inhibitor of CYP51) slowed down the metabolism of BBR, which prevented the production of the demethylated metabolites thalifendine and berberrubine. This study demonstrated that CYP51 promoted the demethylation of BBR and enhanced its intestinal absorption, providing a new method for studying the metabolic transformation mechanism of isoquinoline alkaloids in vivo., Graphical abstract Image 1, Highlights • The demethylation metabolism of natural drugs difficult to absorb through the gut microbiota was first reported. • Six different methods were presented to explain the metabolic mechanism of natural isoquinoline alkaloids. • The findings provided a new idea for studying the mechanism of drug metabolism of gut microbiota.

Gut microbiota is a potent biological modulator of many physiological and pathological states. The renin-angiotensin system (RAS), including the local gastrointestinal RAS (GI RAS), emerges as a potential mediator of microbiota-related effects. The RAS is involved in cardiovascular system homeostasis, water-electrolyte balance, intestinal absorption, glycemic control, inflammation, carcinogenesis, and aging-related processes. Ample evidence suggests a bidirectional interaction between the microbiome and RAS. On the one hand, gut bacteria and their metabolites may modulate GI and systemic RAS. On the other hand, changes in the intestinal habitat caused by alterations in RAS may shape microbiota metabolic activity and composition. Notably, the pharmacodynamic effects of the RAS-targeted therapies may be in part mediated by the intestinal RAS and changes in the microbiome. This review summarizes studies on gut microbiota and RAS physiology. Expanding the research on this topic may lay the foundation for new therapeutic paradigms in gastrointestinal diseases and multiple systemic disorders.

Despite many ongoing and innovative approaches, there are still formidable challenges in the clinical translation of oral peptide drugs into marketable products due to their low absorption and poor bioavailability. Herein, a novel nanocarrier platform was developed that employs a hydrophobic ion-pairing (HIP) of model peptide (insulin) and the anionic bile salt (sodium glycodeoxycholate, SGDC), and markedly improves intestinal absorption via the bile acid pathway. The developed HIP-nanocomplexes (C1 and C2) were optimized, characterized, and in vitro and in vivo evaluation were performed to assess oral efficacy of these system. The optimal molar ratios of C1 and C2-nanocomplexes were 30:1 and 6:1 (SGDC:insulin), respectively. Compared to the insulin solution, the C1 and C2 nanocomplexes significantly enhanced the permeation of insulin across the Caco-2 cell monolayers, with 6.36- and 4.05-fold increases in apparent permeability, respectively. Uptake mechanism studies were conducted using different endocytosis inhibitors and apical sodium-dependent bile acid transporter (ASBT)-transfected MDCK cells, which demonstrated the involvement of the energy-dependent ASBT-mediated active transport. Furthermore, the intrajejunal administration of C1 and C2 resulted in their pharmacological availabilities (PA) being 6.44% and 0.10%, respectively, indicating increased potential for C1, when compared to C2. Similarly, the PA and the relative bioavailability with intrajejunal administration of the C1 were 17.89-fold and 16.82-fold greater than those with intracolonic administration, respectively, confirming better jejunal absorption of C1. Overall, these findings indicate that the HIP-nanocomplexes could be a prominent platform for the effective delivery of peptides with improved intestinal absorption.

Background and purpose Lymphatic transport of drugs after oral administration is an important mechanism for absorption of highly lipophilic compounds. Direct measurement in lymph duct cannulated animals is the gold standard method, but non-invasive cycloheximide chylomicron flow blocking method has gained popularity recently. However, concerns about its reliability have been raised. The aim of this work was to investigate the validity of cycloheximide chylomicron flow blocking method for the evaluation of lymphatic transport using model compounds with high to very high lipophilicity, that is, abiraterone and cinacalcet. Experimental approach Series of pharmacokinetic studies were conducted with abiraterone acetate and cinacalcet hydrochloride after enteral/intravenous administration to intact, lymph duct cannulated and/or cycloheximide pre-treated rats. Key results Mean total absolute oral bioavailability of abiraterone and cinacalcet was 7.0% and 28.7%, respectively. There was a large and significant overestimation of the lymphatic transport extent by the cycloheximide method. Mean relative lymphatic bioavailability of abiraterone and cinacalcet in cycloheximide method was 28-fold and 3-fold higher than in cannulation method, respectively. Conclusion and implications Cycloheximide chylomicron flow blocking method did not provide reliable results on lymphatic absorption and substantially overestimated lymphatic transport for both molecules, that is, abiraterone and cinacalcet. This non-invasive method should not be used for the assessment of lymphatic transport and previously obtained data should be critically revised.

Background. The pathogenesis of chronic inflammatory bowel disease (IBD) is still not fully clarified. It is known that disorders of the intestinal microbiota lead to an increased intestinal permeability, activation of mucous and adaptive immunity, impaired production and intestinal absorption of short-chain fatty acids (SCFA). The ratio of acetic, propionic, butyric acids is an important indicator of the integrity of the intestinal microbial community. Thus, the study of the composition of the intestinal microbiota and the concentrations of fecal SCFA is a very promi­sing approach to broadening the understanding of IBD pathoge­nesis. The purpose of our study was to determine the features of the production of fecal SCFA and the composition of colon microbiota in patients with IBD. Materials and methods. The study, which was carried out at the Department of Intestinal Diseases of the Institute of Gastroenterology of the National Academy of Medical Sciences of Ukraine, involved 74 patients with IBD with an average age of (43.2 ± 1.8) years, who according to nosology were divided into 2 groups: group I — those with ulcerative colitis (UC) (n = 66), group II — individuals with Crohn’s disease (CD) (n = 8). The diagnoses of CD and UC were established accor­ding to generally accepted diagnostic standards in gastroenterology. Determination of fecal SCFA was carried out by chromatographic method with the use of hardware-software complex for medical researches on the basis of the gas chromatographer Chromateс Crystal 5000. The intestinal microflora was evaluated using a microbiological study of the colon content. Results. Patients with IBD had significant changes in the spectrum of SCFA, which were similar in both UC and CD: a decrease in acetic acid in the UC group by 5.7 times, in the CD group by 10.5 times (p, Актуальність. Патогенез хронічних запальних захворювань кишечника (ХЗЗК) досі залишається до кінця не вивченим. Відомо, що порушення мікробіоти кишечника призводять до підвищеної проникності кишечника, порушення продукції та кишкового всмоктування коротколанцюгових жирних кислот (КЖК), співвідношення яких є важливим показником цілісності мікробної спільноти кишечника. Таким чином, вивчення складу мікробіоти кишечника і концентрацій фекальних КЖК є дуже перспективним підходом до розширення розуміння патогенезу ХЗЗК. Метою дослідження було визначити особливості продукції фекальних КЖК та складу мікробіоти товстої кишки у хворих на ХЗЗК. Матеріали та методи. У дослідження, що проводилось у відділенні захворювань кишечника ДУ «Інститут гастроентерології НАМН України», були залучені 74 пацієнти з ХЗЗК, які були розподілені на 2 групи: І група — хворі на неспецифічний виразковий коліт (НВК) (n = 66), II — хворі на хворобу Крона (ХК) (n = 8). Діагнози ХК та НВК були встановлені згідно із загальноприйнятими стандартами діагностики в гастроентерології. Проведене визначення фекальних КЖК, дослідження видового та кількісного складу мікрофлори вмісту кишечника. Результати. У хворих на ХЗЗК виявлені значні зміни в спектрі КЖК, які були аналогічними як при НВК, так і при ХК: зменшення вмісту оцтової кислоти в групі НВК у 5,7 раза і в групі ХК у 10,5 раза (р

Background. Changes in the intestinal microbiome trigger the development and progression of non-alcoholic fatty liver disease (NAFLD). Adverse fluctuations in intestinal microbiota are associated with increased intestinal permeability, activation of mucosal and adaptive immunity, increase in production and intestinal absorption of short-chain fatty acids (SCFA). The ratio of acetic, propionic, butyric acid is an important indicator of the integrity of the microbial community of the intestine. Thus, the study of the gut microbiota composition and short-chain fatty acids production represents a very appealing approach to increasing our knowledge about the mechanisms leading to NAFLD in children. The purpose of the study was to determine the features of the fecal short-chain fatty acids (fSCFA) content and the colonic microbiota composition in children with NAFLD. Materials and methods. A comprehensive examination of 102 children was provided in the Department of Pediatric Gastroenterology of the Institute of Gastroenterology of the National Academy of Medical Sciences of Ukraine. According to the presence of obesity, transient elastography data and alanine aminotransferase levels the patients were divided into four groups: I group — children with simple hepatic steatosis (n = 24); II group — children with nonalcoholic steatohepatitis (NASH) (n = 14); III group — children with obesity without steatosis (n = 48), IV group — children with normal weight (n = 16). Chromatographic study of fSCFA was conducted using gas chromatograph Chromatec-Crystal 5000. The microorganisms were identified using a microbiological study of the colon content. Diagnosis of NAFLD was established with FibroScan 502 Touch (Echosens, France) with the determination of the controlled attenuation parameter. Results. Significant changes in the spectrum of fSCFA were observed in children of the III group with acetic acid content increased by 4.8 times (р

Titanium dioxide nanoparticles (TiO2 NPs) as food additives were widely found in various foodrelated products, especially in high-sugar foods. The daily intake of TiO2 NPs in the diet may therefore expose the small intestine to TiO2 NPs and affect its physiological functions, including the absorption of nutrients. It is speculated that TiO2 may cause serious health hazards by increasing sugar uptake. To explore this possibility, transport of glucose from small intestine was studied using an everted gut sac model prepared from small intestine of young healthy male SD rats. The translocation of TiO2 NPs and the morphological changes of small intestine were also observed after exposure of intestinal lumen to TiO2 NPs for 2 h. The results showed that TiO2 NPs can enter into enterocyte but hardly cross the intestinal epithelium. No change on microstructure of gut epithelia and expression of glucose transporter was found, and there is no obvious impact on intestinal absorption and metabolism of glucose. These results suggest that short-term exposure to TiO2 NPs has little influence on intestinal absorption of glucose. More attention should be paid to the chronic effect of dietary consumption of TiO2 NPs on nutrient absorption.

Hyperlipidemia is a disorder of lipid metabolism, which is a major cause of coronary heart disease. Although there has been considerable progress in hyperlipidemia treatment, morbidity and risk associated with the condition continue to rise. The first-line treatment for hyperlipidemia, statins, has multiple side effects; therefore, development of safe and effective drugs from natural products to prevent and treat hyperlipidemia is necessary. Diosgenin is primarily derived from fenugreek (Trigonella foenum graecum) seeds, and is also abundant in medicinal herbs such as Dioscorea rhizome, Dioscorea septemloba, and Rhizoma polygonati, is a well-known steroidal sapogenin and the active ingredient in many drugs to treat cardiovascular conditions. There is abundant evidence that diosgenin has potential for application in correcting lipid metabolism disorders. In this review, we evaluated the latest evidence related to diosgenin and hyperlipidemia from clinical and animal studies. Additionally, we elaborate the pharmacological mechanism underlying the activity of diosgenin in treating hyperlipidemia in detail, including its role in inhibition of intestinal absorption of lipids, regulation of cholesterol transport, promotion of cholesterol conversion into bile acid and its excretion, inhibition of endogenous lipid biosynthesis, antioxidation and lipoprotein lipase activity, and regulation of transcription factors related to lipid metabolism. This review provides a deep exploration of the pharmacological mechanisms involved in diosgenin-hyperlipidemia interactions and suggests potential routes for the development of novel drug therapies for hyperlipidemia.

Short bowel syndrome (SBS) is associated with diminished levels of serum fats caused by unknown mechanisms. We have shown that mesenteric lymphatics remodel to a more primitive state one week after small bowel resection (SBR); therefore, this study focuses on the effect of chronic lymphatic remodeling and magnitude of resection on intestinal fatty acid uptake and transport. C57BL6 and Prox1 creER-Rosa26LSLTdTomato (lymphatic reporter) mice underwent 50% or 75% proximal SBR or sham operations. Functional transport of lipids and fecal fat content was measured and lymphatic vasculature was compared via imaging. There was a significant reduction in functional transport of cholesterol and triglyceride after SBR with increasing loss of bowel, mirrored by a progressive increase in fecal fat content. We also describe significant morphological changes in the lymphatic vasculature in both the lamina propria and mesentery. Intestinal lymphatic drainage assay in vivo demonstrated a marked reduction of systemic absorption after resection. Intestinal lymphatic vessels significantly remodel in the setting of chronic SBS. This remodeling results in impaired intestinal transport of fat via the compromised lymphatic architecture, contributing to decreased fatty acid uptake. We believe that these changes may contribute to the development of IFALD, a major morbidity in patients with SBS.

Background Short bowel syndrome is an uncommon malabsorptive condition most frequently caused by massive surgical resection of the small intestine. Standard of care is home parenteral nutrition. Teduglutide, glucagon like peptide 2 analog, was approved to treat patients with short bowel syndrome, who are stable following a period of post-surgery intestinal adaptation. Case presentation We report two cases of patients with short bowel syndrome on home parenteral nutrition, treated with teduglutide, novel advanced therapy. We monitored the effectiveness and tolerance of the new treatment. Conclusion Teduglutide increases intestinal absorption, causes cryptal hyperplasia, villous hypertrophy, angiogenesis, and allows weaning from parenteral nutrition. We confirmed the early onset of treatment effectiveness in the 4th month. Early effectiveness of treatment allowed a reduction in the volume of home parenteral nutrition with an improvement in quality of life.

Aims Atherosclerotic cardiovascular disease (ACVD) is a major cause of mortality and morbidity worldwide, and increased low-density lipoproteins (LDLs) play a critical role in development and progression of atherosclerosis. Here, we examined for the first time gut immunomodulatory effects of the microbiota-derived metabolite propionic acid (PA) on intestinal cholesterol metabolism. Methods and results Using both human and animal model studies, we demonstrate that treatment with PA reduces blood total and LDL cholesterol levels. In apolipoprotein E−/− (Apoe −/−) mice fed a high-fat diet (HFD), PA reduced intestinal cholesterol absorption and aortic atherosclerotic lesion area. Further, PA increased regulatory T-cell numbers and interleukin (IL)-10 levels in the intestinal microenvironment, which in turn suppressed the expression of Niemann-Pick C1-like 1 (Npc1l1), a major intestinal cholesterol transporter. Blockade of IL-10 receptor signalling attenuated the PA-related reduction in total and LDL cholesterol and augmented atherosclerotic lesion severity in the HFD-fed Apoe −/− mice. To translate these preclinical findings to humans, we conducted a randomized, double-blinded, placebo-controlled human study (clinical trial no. NCT03590496). Oral supplementation with 500 mg of PA twice daily over the course of 8 weeks significantly reduced LDL [−15.9 mg/dL (−8.1%) vs. −1.6 mg/dL (−0.5%), P = 0.016], total [−19.6 mg/dL (−7.3%) vs. −5.3 mg/dL (−1.7%), P = 0.014] and non-high-density lipoprotein cholesterol levels [PA vs. placebo: −18.9 mg/dL (−9.1%) vs. −0.6 mg/dL (−0.5%), P = 0.002] in subjects with elevated baseline LDL cholesterol levels. Conclusion Our findings reveal a novel immune-mediated pathway linking the gut microbiota-derived metabolite PA with intestinal Npc1l1 expression and cholesterol homeostasis. The results highlight the gut immune system as a potential therapeutic target to control dyslipidaemia that may introduce a new avenue for prevention of ACVDs.

The objective of this work was to evaluate in vitro bioaccessibility, intestinal absorption, antioxidant and angiotensin I-converting enzyme (ACE) inhibitory activities of peptides from rainbow trout viscera hydrolysate (H). Rainbow trout Viscera (V) was hydrolyzed by Alcalase® 2.4L and a degree of hydrolysis (DH) of 44.8 ± 2.5% was achieved. Viscera and its hydrolysate were subjected to simulated gastrointestinal digestion (SGID) and intestinal absorption across Caco-2/TC7 cell monolayers. After the hydrolysis with Alcalase® 2.4L and the SGID of V, the species between 60.6 kDa and 13.0 kDa were decreased, causing an increase in species less than 6.51 kDa. The SGID of H did not modify the oxygen radical absorbance capacity (ORAC) or ACE inhibitory values but caused a significant decrease in the hydroxyl radical antioxidant capacity (HORAC) (30.2%). It also produced an increase in ABTS radical cation (ABTS assay) scavenging activity and ferric reducing antioxidant power (FRAP) (9.46% and 20.2%, respectively). Bioactive peptides in H were stable after SGID and they were partially able to cross Caco-2/TC7 cell monolayer, which demonstrates their possible intestinal absorption and their potential to act inside the organism. Resumen: El objetivo de este trabajo fue evaluar la bioaccesibilidad in vitro, la absorción intestinal, las actividades inhibidoras de antioxidantes y de la enzima convertidora de angiotensina I (ECA) de péptidos del hidrolizado de vísceras de trucha arco iris (H). La trucha arco iris Viscera (V) fue hidrolizada por Alcalase® 2.4L y se logró un grado de hidrólisis (DH) de 44.8 ± 2.5%. Las vísceras y su hidrolizado se sometieron a digestión gastrointestinal simulada (SGID) y absorción intestinal a través de monocapas de células Caco-2 / TC7. Tras la hidrólisis con Alcalase® 2.4L y el SGID de V, las especies entre 60,6 kDa y 13,0 kDa disminuyeron, provocando un aumento de especies menores a 6,51 kDa. El SGID de H no modificó la capacidad de absorbancia de radicales de oxígeno (ORAC) ni los valores inhibidores de la ECA, pero provocó una disminución significativa en la capacidad antioxidante del radical hidroxilo (HORAC) (30,2%). También produjo un aumento en la actividad de eliminación de cationes radicales ABTS (ensayo ABTS) y en el poder antioxidante reductor férrico (FRAP) (9,46% y 20,2%, respectivamente). Los péptidos bioactivos en H se mantuvieron estables después de SGID y fueron parcialmente capaces de cruzar la monocapa de células Caco-2 / TC7, lo que demuestra su posible absorción intestinal y su potencial para actuar dentro del organismo. Instituto de Investigación de Tecnología de Alimentos (ITA) Fil: Vásquez, Priscilla. Universidad de Antioquia. Facultad de Ciencias Farmacéuticas y de los Alimentos. Departamento de Alimentos; Colombia. Fil: Zapata, José E. Universidad de Antioquia. Facultad de Ciencias Farmacéuticas y de los Alimentos. Departamento de Alimentos; Colombia. Fil: Chamorro, Verónica Celeste. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Investigación Tecnología de Alimentos; Argentina. Fil: García Fillería, Susan F. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas - Universidad Nacional de La Plata - Comisión de Investigaciones Científicas de la Provincia de Buenos Aires; Argentina. Fil: Tironi, Valeria A. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas - Universidad Nacional de La Plata - Comisión de Investigaciones Científicas de la Provincia de Buenos Aires; Argentina.

Background: Treatment with glucagon-like peptide-2 (GLP-2) analogs improve intestinal adaptation in patients with short bowel syndrome–associated intestinal failure (SBS-IF) and may reduce parenteral support requirements. Apraglutide is a novel, long-acting GLP-2 analog designed for once-weekly dosing. This trial investigated the safety and efficacy of apraglutide in patients with SBS-IF. Methods: In this placebo-controlled, double-blind, randomized, crossover phase 2 trial, eight adults with SBS-IF were treated with once-weekly 5-mg apraglutide doses and placebo for 4 weeks, followed by once-weekly 10-mg apraglutide doses for 4 weeks, with a washout period of 6–10 weeks between treatments. Safety was the primary end point. Secondary end points included changes from baseline in urine volume output compared with placebo, collected for 48 h before and after each treatment period. Results: Common treatment-related adverse events (AEs) were mild to moderate and included polyuria, decreased stoma output, stoma complications, decreased thirst, and edema. No serious AEs were considered to be related to apraglutide treatment. The safety profile was comparable for the lower and higher doses. Treatment with once-weekly 5- and 10-mg apraglutide doses significantly increased urine volume output by an adjusted mean of 714 ml/day (95% CI, 490–939; P

Intestinal surface changes in size and function, but what propels these alterations and what are their metabolic consequences is unknown. Here we report that the food amount is a positive determinant of the gut surface area contributing to an increased absorptive function, reversible by reducing daily food. While several upregulated intestinal energetic pathways are dispensable, the intestinal PPAR alpha is instead necessary for the genetic and environment overeating-induced increase of the gut absorptive capacity. In presence of dietary lipids, intestinal PPAR alpha knock-out or its pharmacological antagonism suppress intestinal crypt expansion and shorten villi in mice and in human intestinal biopsies, diminishing the postprandial triglyceride transport and nutrient uptake. Intestinal PPAR alpha ablation limits systemic lipid absorption and restricts lipid droplet expansion and PLIN2 levels, critical for droplet formation. This improves the lipid metabolism, and reduces body adiposity and liver steatosis, suggesting an alternative target for treating obesity., Nature Communications, 12, ISSN:2041-1723

International audience; (1) Background: vitamin E is often supplemented in the form of tocopherol acetate, but it has poor bioavailability and can fail to correct blood tocopherol concentrations in some patients with severe cholestasis. In this context, α-tocopheryl polyethylene glycol succinate 1000 (TPGS) has been of value, but very little is known about the mechanisms of its absorption. The aim of our work was to evaluate the mechanisms of absorption/secretion of TPGS compared to tocopherol acetate (TAC) and α-tocopherol by human enterocyte-like Caco-2 TC7 cells. (2) Methods: two weeks post-confluence Caco-2 cells were incubated with tocopherol- or TAC- or TPGS-rich mixed micelles up to 24 h and, following lipid extraction, TAC and tocopherol amounts were measured by high performance liquid chromatography (HPLC) in apical, cellular, and basolateral compartments. (3) Results: at equivalent concentrations of tocopherol in the apical side, the amounts of tocopherol secreted at the basolateral pole of Caco-2 cells are (i) significantly greater when the tocopherol is in the free form in the micelles; (ii) intermediate when it is in the TAC form in the micelles (p \textless 0.001); and (iii) significantly lower with the TPGS form (p \textless 0.0001). Interestingly, our results show, for the first time, that Caco-2 cells secrete one or more esterified forms of the vitamin contained in TPGS at the basolateral side.

Significance Significant calcium absorption across renal and intestinal epithelia occurs via the paracellular pathway. However, the identity of the paracellular pore involved is unknown. Claudin-2 and claudin-12 contribute paracellular calcium permeability in cell models, but single knockout animals don’t have altered serum calcium or bone mineralization. To investigate this, Cldn2/12 double knockout mice were generated. They display decreased intestinal calcium absorption and renal calcium wasting, resulting in hypocalcemia and markedly reduced bone mineralization. Claudin-2 and claudin-12 don’t physically interact in vitro, and coexpression has an additive effect on calcium permeability. Our work identifies claudin-2 and claudin-12 as important constituents of the paracellular Ca2+ pathway in intestine and kidney enabling calcium transport and highlights their important complementary roles in maintaining calcium homeostasis., Calcium (Ca2+) homeostasis is maintained through coordination between intestinal absorption, renal reabsorption, and bone remodeling. Intestinal and renal (re)absorption occurs via transcellular and paracellular pathways. The latter contributes the bulk of (re)absorption under conditions of adequate intake. Epithelial paracellular permeability is conferred by tight-junction proteins called claudins. However, the molecular identity of the paracellular Ca2+ pore remains to be delineated. Claudins (Cldn)-2 and -12 confer Ca2+ permeability, but deletion of either claudin does not result in a negative Ca2+ balance or increased calciotropic hormone levels, suggesting the existence of additional transport pathways or parallel roles for the two claudins. To test this, we generated a Cldn2/12 double knockout mouse (DKO). These animals have reduced intestinal Ca2+ absorption. Colonic Ca2+ permeability is also reduced in DKO mice and significantly lower than single-null animals, while small intestine Ca2+ permeability is unaltered. The DKO mice display significantly greater urinary Ca2+ wasting than Cldn2 null animals. These perturbations lead to hypocalcemia and reduced bone mineral density, which was not observed in single-KO animals. Both claudins were localized to colonic epithelial crypts and renal proximal tubule cells, but they do not physically interact in vitro. Overexpression of either claudin increased Ca2+ permeability in cell models with endogenous expression of the other claudin. We find claudin-2 and claudin-12 form partially redundant, independent Ca2+ permeable pores in renal and colonic epithelia that enable paracellular Ca2+ (re)absorption in these segments, with either one sufficient to maintain Ca2+ balance.

Context There is no licensed oral native testosterone (NT) because of challenges in the formulation. Licensed oral formulations of the ester, testosterone undecanoate (TU), require a meal for absorption and generate supraphysiological dihydrotestosterone (DHT) levels. Objective To develop an oral NT formulation. Design and methods A lipid-based formulation of native testosterone filled into soft-gelatin capsules at 40 mg per capsule was designed with 2 years of stability at ambient temperature. Pharmacokinetic comparison studies of this oral lipidic NT formulation to oral TU were conducted in dogs and hypogonadal men. Results In dogs, 40 mg NT was well absorbed under fasted conditions whereas 40 mg TU required a high-fat meal: for NT, the mean fed/fasted AUC ratio was 1.63 and for TU 7.05. In hypogonadal men, fed and fasted NT had similar pharmacokinetics: Cmax mean 26.5 vs 30.4 nmol/L (769 vs 882 ng/dL), AUC0–10 h 87 vs 88.6 h nmol/L. NT (fed state) showed a testosterone AUC increase of 45% between 120 and 200 mg, and NT 200 mg gave a similar mean AUC0–10 h to TU 80 mg: 87 vs 64.8 h nmol/L. Serum TU levels were variable and on a molar basis were ~ten-fold higher than serum testosterone levels after TU 80 mg fed. The DHT: testosterone AUC0–10 h ratio was more physiological for NT than TU being 0.19 vs 0.36. There were no emerging safety concerns with NT. Conclusion This novel oral lipidic native testosterone formulation has potential advantages over oral TU of dosing independently of food and a lower risk of supraphysiological DHT levels. Significance statement There is no licensed oral testosterone because of challenges in formulation, and the oral formulations of the ester, testosterone undecanoate, require a fatty meal for absorption and generate supraphysiological dihydrotestosterone levels. We have overcome the design challenges and formulated an oral native testosterone that can be taken with or without food and provides physiological levels of testosterone and dihydrotestosterone in hypogonadal men. This formulation, DITEST, has the potential advantage of being oral for patients who do not tolerate injections and less risk of adverse events that might theoretically be associated with elevated dihydrotestosterone levels. Future studies will need to define the dosing regimen for replacement in hypogonadal men.

Objectives To assess whether weaning to an extensively hydrolyzed formula (EHF) decreases gut permeability and/or markers of intestinal inflammation in infants with HLA-conferred diabetes susceptibility, when compared with conventional formula. Study design By analyzing 1468 expecting biological parent pairs for HLA-conferred susceptibility for type 1 diabetes, 465 couples (32 %) potentially eligible for the study were identified. After further parental consent, 332 babies to be born were randomized at 35th gestational week. HLA genotyping was performed at birth in 309 infants. Out of 87 eligible children, 73 infants participated in the intervention study: 33 in the EHF group and 40 in the control group. Clinical visits took place at 3, 6, 9, and 12 months of age. The infants were provided either EHF or conventional formula whenever breastfeeding was not available or additional feeding was required over the first 9 months of life. The main outcome was the lactulose to mannitol ratio (L/M ratio) at 9 months. The secondary outcomes were L/M ratio at 3, 6, and 12 months of age, and fecal calprotectin and human beta-defensin 2 (HBD-2) levels at each visit. Results Compared with controls, the median L/M ratio was lower in the EHF group at 9 months (.006 vs .028; P = .005). Otherwise, the levels of intestinal permeability, fecal calprotectin, and HBD-2 were comparable between the two groups, although slight differences in the age-related dynamics of these markers were observed. Conclusions It is possible to decrease intestinal permeability in infancy through weaning to an extensively hydrolyzed formula. This may reduce the early exposure to dietary antigens. Trial registration Clinicaltrials.gov : NCT01735123.

Emerging information suggests that pathology of the kidney may not only affect expression and function of membrane transporters in the organ, but also in the gastrointestinal tract and the liver. Transporter dysfunction may cause effects on handling of drug as well as endogenous compounds with subsequent clinical consequences. A literature search was conducted on Ovid and PubMed databases to select relevant in vitro, animal and human studies that have reported expression, protein abundance and function of the gastrointestinal and liver localized ABC transporters and SLC carriers in kidney dysfunction or uremia states. The altered function of drug transporters in the liver and intestines in kidney failure subjects may provide compensatory activity in handling endogenous compounds (e.g. uremic toxins), which is expected to affect drug pharmacokinetics and local drug actions.

International audience; Scope Most people are vitamin D insufficient around the world. Vitamin D intestinal absorption should thus be optimized. The role of the ATP-binging cassette G5/G8 (ABCG5/G8) heterodimer in vitamin D intestinal efflux is investigated. Methods and Results Both cholecalciferol and 25-hydroxycholecalciferol apical effluxes are increased by ABCG5/G8 overexpression in human Griptite cells. Mice deficient in ABCG5/G8 at the intestinal level (I-Abcg5/g8(-/-) mice) display an accumulation of cholecalciferol in plasma in females and in liver in males compared to control animals. I-Abcg5/g8(-)(/)(-) mice display a delay in cholecalciferol postprandial response after gavage compared with controls. 25-Hydroxycholecalciferol transfer from plasma to lumen is observed in vivo in intestine-perfused mice, and the lack of intestinal ABCG5/G8 complex induces a decrease in this efflux, while vitamin D bile excretion remains unchanged. Conclusion Overall, it is showed for the first time that the ABCG5/G8 heterodimer regulates the kinetics of absorption of dietary vitamin D by contributing to its efflux back to the lumen, and that it also participates in vitamin D transintestinal efflux.

Lavandula pedunculata (Mill.) Cav. (LP) is one of lavender species traditionally used in Morocco to prevent or cure diabetes, alone or in the form of polyherbal preparations (PHP). Therefore, the primary objective of this study was to test the antihyperglycemic effect of the aqueous extract of LP, alone and in combination with Punica granatum L. (PG) and Trigonella foenum-graecum L. (FGK). The secondary objective was to explore some mechanisms of action on the digestive functions. The antihyperglycemic effect of the aqueous extract of LP, alone and in combination with PG and FGK, was studied in vivo using an oral glucose tolerance test (OGTT). In addition, LP extract was tested on the activities of some digestive enzymes (pancreatic α-amylase and intestinal α-glucosidase) in vitro and on the intestinal absorption of glucose ex vivo using a short-circuit current (Isc) technique. Acute and chronic oral administration of LP aqueous extract reduced the peak of the glucose concentration (30 min, p < 0.01) and the area under the curve (AUC, p < 0.01). The effect of LP + PG was at the same amplitude to that of the positive control Metformin (MET). LP aqueous extract inhibited the pancreatic α-amylase with an IC50 almost identical to acarbose (0.44 ± 0.05 mg/mL and 0.36 ± 0.02 mg/mL, respectively), as well as the intestinal α-glucosidase, (IC50 = 131 ± 20 µg/mL) and the intestinal glucose absorption (IC50 = 81.28 ± 4.01 µg/mL) in concentration-dependent manners. LP aqueous extract exhibited potent actions on hyperglycemia, with an inhibition on digestive enzymes and glucose absorption. In addition, the combination with PG and FGK enhanced oral glucose tolerance in rats. These findings back up the traditional use of LP in type 2 diabetes treatment and the effectiveness of the alternative and combinative poly-phytotherapy (ACPP).

Purpose: The aim of this study was to evaluate the intraluminal behavior of various transporter substrates in different regions of the gastrointestinal (GI) tract. Methods: Drug solutions containing non-absorbable FITC-dextran 4000 (FD-4), were orally administered to rats. Residual water was sampled from the GI regions to measure the luminal drug concentration. Results: Cephalexin (CEX), a substrate of the proton-coupled oligopeptide transporter, was absorbed rapidly, and no drug was detected in the lower small intestine. Saquinavir (SQV) was primarily absorbed in the upper region. However, unlike CEX, SQV was detected even in the lower segment probably due to the efflux of SQV via P-glycoprotein (P-gp). The concentration of methotrexate (MTX) showed a similar pattern to that of non-absorbable FD-4. The low absorption of MTX was probably due to efflux via several efflux transporters, and the limited expression of proton-coupled folate transporter, an absorptive transporter for MTX, in the upper region. Conclusion: This study revealed that the luminal concentration pattern of each drug differed considerably depending on the site because of the different absorption properties and luminal volumes. Although further investigation using a specific transporter inhibitor or transporter-knockout animals are necessary to clarify the actual contribution of each transporter to the drug absorption, this information will be valuable in evaluating transporter-mediated drug absorption in in vitro transport studies for ensuring optimal drug concentrations.

The study was conducted to evaluate the effects of low crude protein diets supplemented with arginine, glutamine, methionine, and/or threonine on apparent ileal digestibility of amino acids, intestinal morphology, intestinal permeability, gene expression of nutrient transporters, and tight junction proteins of broiler chickens challenged with mixed Eimeria spp. A total of five hundred seventy-six, 12-day-old male broiler chickens were allocated into 8 treatments, and 6 replicate cages of 12 chickens per cage. This experiment included a nonchallenged control (NC) fed regular corn-soybean meal-based diet (Regular diet, 19% crude protein), an Eimeria-challenged control (CC) fed Regular diet, an Eimeria challenge group fed low-crude protein diet (LCP, 16% crude protein), 4 Eimeria challenge groups fed low-crude protein diet supplemented with 0.75% arginine, glutamine, methionine, and threonine, respectively (ARG, GLN, MET, and THR), and an Eimeria challenge group fed low-crude protein diet with 0.75% supplemented arginine, glutamine, methionine, and threonine collectively as a combination group (COMB). On d 14, birds in the challenge groups were gavaged with a mixed Eimeria spp. solution containing 12,500 oocysts of E. maxima, 12,500 oocysts of E. tenella, and 62,500 oocysts of E. acervulina. The results showed that the Eimeria challenge reduced overall growth performance, but the LCP had no adverse impacts on intestinal health and growth of Eimeria-infected birds compared to the CC. Additionally, supplementation of crystalline arginine, glutamine, methionine, and threonine improved the apparent ileal digestibility of these specific amino acids on 6 dpi. Moreover, the THR treatment increased villus height in the duodenum. The ARG treatment decreased intestinal permeability and gene expression of amino acid transporters, whereas the GLN and THR treatments both reversed adverse effects of coccidiosis on gene expression of tight junction protein (claudin 1). However, the MET and COMB treatments exacerbated infection severity of coccidiosis. In summary, adding 0.75% of arginine, glutamine, or threonine in a low crude protein diet can improve the intestinal health of birds challenged with a mild coccidia infection.

Nephrolithiasis is a worldwide problem with increasing prevalence, enormous costs, and significant morbidity. Calcium-containing kidney stones are by far the most common kidney stones encountered in clinical practice. Consequently, hypercalciuria is the greatest risk factor for kidney stone formation. Hypercalciuria can result from enhanced intestinal absorption, increased bone resorption, or altered renal tubular transport. Kidney stone formation is complex and driven by high concentrations of calcium-oxalate or calcium-phosphate in the urine. After discussing the mechanism mediating renal calcium salt precipitation, we review recent discoveries in renal tubular calcium transport from the proximal tubule, thick ascending limb, and distal convolution. Furthermore, we address how calcium is absorbed from the intestine and mobilized from bone. The effect of acidosis on bone calcium resorption and urinary calcium excretion is also considered. Although recent discoveries provide insight into these processes, much remains to be understood in order to provide improved therapies for hypercalciuria and prevent kidney stone formation. Expected final online publication date for the Annual Review of Physiology, Volume 84 is February 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

BackgroundImpaired intestinal barrier integrity plays a crucial role in the development of many diseases such as obesity, inflammatory bowel disease, and type 2 diabetes. Thus, protecting the intestinal barrier from pathological disruption is of great significance. Tryptophan can increase gut barrier integrity, enhance intestinal absorption, and decrease intestinal inflammation. However, the mechanism of tryptophan in decreasing intestinal barrier damage and inflammatory response remains largely unknown. The objective of this study was to test the hypothesis that tryptophan can enhance intestinal epithelial barrier integrity and decrease inflammatory response mediated by the calcium-sensing receptor (CaSR)/Ras-related C3 botulinum toxin substrate 1 (Rac1)/phospholipase Cγ1 (PLC-γ1) signaling pathway.MethodsIPEC-J2 cells were treated with or without enterotoxigenic Escherichia coli (ETEC) K88 in the absence or presence of tryptophan, CaSR inhibitor (NPS-2143), wild-type CaSR overexpression (pcDNA3.1-CaSR-WT), Rac1-siRNA, and PLC-γ1-siRNA.ResultsThe results showed that ETEC K88 decreased the protein concentration of occludin, zonula occludens-1 (ZO-1), claudin-1, CaSR, total Rac1, Rho family member 1 of porcine GTP-binding protein (GTP-rac1), phosphorylated phospholipase Cγ1 (p-PLC-γ1), and inositol triphosphate (IP3); suppressed the transepithelial electrical resistance (TEER); and enhanced the permeability of FITC-dextran compared with the control group. Compared with the control group, 0.7 mM tryptophan increased the protein concentration of CaSR, total Rac1, GTP-rac1, p-PLC-γ1, ZO-1, claudin-1, occludin, and IP3; elevated the TEER; and decreased the permeability of FITC-dextran and contents of interleukin-8 (IL-8) and TNF-α. However, 0.7 mM tryptophan+ETEC K88 reversed the effects induced by 0.7 mM tryptophan alone. Rac1-siRNA+tryptophan+ETEC K88 or PLC-γ1-siRNA+tryptophan+ETEC K88 reduced the TEER, increased the permeability of FITC-dextran, and improved the contents of IL-8 and TNF-α compared with tryptophan+ETEC K88. NPS2143+tryptophan+ETEC K88 decreased the TEER and the protein concentration of CaSR, total Rac1, GTP-rac1, p-PLC-γ1, ZO-1, claudin-1, occludin, and IP3; increased the permeability of FITC-dextran; and improved the contents of IL-8 and TNF-α compared with tryptophan+ETEC K88. pcDNA3.1-CaSR-WT+Rac1-siRNA+ETEC K88 and pcDNA3.1-CaSR-WT+PLC-γ1-siRNA+ETEC K88 decreased the TEER and enhanced the permeability in porcine intestine epithelial cells compared with pcDNA3.1-CaSR-WT+ETEC K88.ConclusionTryptophan can improve intestinal epithelial barrier integrity and decrease inflammatory response through the CaSR/Rac1/PLC-γ1 signaling pathway.

In this paper, we reviewed the role of dairy products in dietary zinc absorption. Dairy products can have a reasonable contribution for dietary zinc intake in Western diets, where dairy consumption is high. However, the co-ingestion of dairy products can also improve zinc absorption from other food products. Such improvements have been observed when dairy products (e.g., milk or yoghurt) were ingested together with food such as rice, tortillas or bread products, all of which are considered to be high-phytate foods with low inherent zinc absorption. For foods low in phytate, the co-ingestion of dairy products did not improve zinc absorption. Improved zinc absorption of zinc from high-phytate foods following co-ingestion with dairy products may be related to the beneficial effects of the citrate and phosphopeptides present in dairy products. Considering that the main dietary zinc sources in areas in the world where zinc deficiency is most prevalent are typically high in phytate, the inclusion of dairy products in meals may be a viable dietary strategy to improve zinc absorption.

Iron is an essential trace metal for almost all organisms, including human; however, oxidative stress can easily be caused when iron is in excess, producing toxicity to the human body due to its capability to be both an electron donor and an electron acceptor. Although there is a strict regulation mechanism for iron homeostasis in the human body and brain, it is usually inevitably disturbed by genetic and environmental factors, or disordered with aging, which leads to iron metabolism diseases, including many neurodegenerative diseases such as Alzheimer’s disease (AD). AD is one of the most common degenerative diseases of the central nervous system (CNS) threatening human health. However, the precise pathogenesis of AD is still unclear, which seriously restricts the design of interventions and treatment drugs based on the pathogenesis of AD. Many studies have observed abnormal iron accumulation in different regions of the AD brain, resulting in cognitive, memory, motor and other nerve damages. Understanding the metabolic balance mechanism of iron in the brain is crucial for the treatment of AD, which would provide new cures for the disease. This paper reviews the recent progress in the relationship between iron and AD from the aspects of iron absorption in intestinal cells, storage and regulation of iron in cells and organs, especially for the regulation of iron homeostasis in the human brain and prospects the future directions for AD treatments.