Entire Small Intestine Research Articles

Association of Slowly Digestible Starch Intake with Reduction of Postprandial Glycemic Response: An Update Meta-Analysis.

Slowly digestible starch (SDS) has been shown to digest slowly throughout the entire small intestine, generating slow and prolonged release of glucose, according to the in vitro Englyst assay. The aim of this work was to conduct a meta-analysis of up-to-date evidence to evaluate the association between SDS consumption and a reduction in the postprandial glycemic response, including extended glycemic index (EGI) or glycemic profile (GP) parameters, during in vivo digestion. We searched the Web of Science, PubMed, Europe PMC, Cochrane Library, and Embase to identify related articles published up to September 2022. Human trials investigating the effect of the SDS amount on the postprandial glucose profile were estimated at the standard mean difference (SMD), with a 95% confidence interval (CI), using random effect models. The review followed the systematic reviews and meta-analyses (PRISMA) guidelines. The meta-analysis included a total of 65 participants. The results revealed that the EGI experienced a greater increase (SMD = 24.61, I2 = 79.2%, p < 0.01) after SDS intake, while the GP exhibited similar trends (SMD = 29.18, I2 = 73.3%, p < 0.01). High heterogeneity vanished in the subgroup and sensitivity analysis (EGI: I2 = 14.6%, p = 0.31; GP: I2 = 0.0%, p = 0.97). There was no evidence of publication bias for EGI (p = 0.41) or GP (p = 0.99).The present meta-analysis provides evidence that SDS intake is positively correlated with EGI and GP levels. The quantitative relationship of the reduction in the postprandial glycemic response and SDS consumption was used to quantify the slow digestion property on an extended time scale, and supplement the in vitro concept of SDS.

Time-Based Formulation Strategies for Colon Drug Delivery.

Despite poor absorption properties, delivery to the colon of bioactive compounds administered by the oral route has become a focus of pharmaceutical research over the last few decades. In particular, the high prevalence of Inflammatory Bowel Disease has driven interest because of the need for improved pharmacological treatments, which may provide high local drug concentrations and low systemic exposure. Colonic release has also been explored to deliver orally biologics having gut stability and permeability issues. For colon delivery, various technologies have been proposed, among which time-dependent systems rely on relatively constant small intestine transit time. Drug delivery platforms exploiting this physiological feature provide a lag time programmed to cover the entire small intestine transit and control the onset of release. Functional polymer coatings or capsule plugs are mainly used for this purpose, working through different mechanisms, such as swelling, dissolution/erosion, rupturing and/or increasing permeability, all activated by aqueous fluids. In addition, enteric coating is generally required to protect time-controlled formulations during their stay in the stomach and rule out the influence of variable gastric emptying. In this review, the rationale and main delivery technologies for oral colon delivery based on the time-dependent strategy are presented and discussed.

S3463 Primary Intestinal Follicular Lymphoma

Introduction: Follicular Lymphoma (FL) mostly presents as a nodal lymphoma, however primary extranodal involvement is rare. The gastrointestinal tract is the most common site of extranodal FL, and with rates of FL increasing it remains important to recognize the characteristic endoscopic features of the disease. It typically carries an indolent course that may not even require treatment. We present a case of primary intestinal FL that involved the entire small intestine. Case Description/Methods: A 53-year-old Hispanic male with a history of gastrointestinal reflux disease (GERD), presented with refractory GERD symptoms despite maximal PPI therapy. An upper endoscopy was performed and revealed an irregular Z line, gastritis and numerous, patchy, small (< 1cm), white nodules in the second and third portion of the duodenum. Multiple biopsies were taken from the nodules. Pathology revealed Grade I-II FL. Capsule endoscopy was performed and revealed numerous similar lesions throughout the entire small intestine. He was referred to Oncology and underwent PET-CT scan which revealed multiple FDG-avid abdominopelvic lymph nodes. After discussion with Oncology, the patient elected for a watch and wait approach. Repeat PET-CT scan 6 months later revealed multiple abdominopelvic lymph nodes that are no longer FDG-avid. He remains asymptomatic and will be monitored closely off therapy. (Figure) Discussion: The most common primary intestinal lymphomas are diffuse large B-cell lymphoma (DLBCL) and mucosa associated lymphoid tissue (MALT) Lymphoma. FL only comprises approximately 1-2% of primary intestinal lymphomas. The small intestine is the most common location, with the second portion of the duodenum as the most likely site of involvement. It is rarely seen in the colon and stomach and there are no reported cases of esophageal involvement. Rates of diagnosis are on the rise, thus highlighting the importance of endoscopic recognition as it may often be seen in the second portion of the duodenum on routine upper endoscopy. Given the indolent course of FL, a watch and wait approach may be reasonable. Other options for therapy include chemotherapy, Rituximab, or radiation.Figure 1.: White nodular mass in duodenum visualized on capsule endoscopy consistent with patient's known diagnosis of Follicular Lymphoma.

A Rare Cause of Repeated Life-Threatening Gastrointestinal Bleeding

Question: A 53-year-old man was referred to our hospital because of a nearly 4.5-year history of hematochezia and abdominal pain. He had 4 episodes of gastrointestinal bleeding in the first 7 months of the history. Repeated gastroscopy and colonoscopy were performed during that period, but no abnormal lesions were found. Single-balloon enteroscopy for the entire small intestine showed a 0.3 × 0.3 cm ulcer without active bleeding in the distal duodenum (Figure A). The patient received medical treatment, and enteroscopy re-examination 1 month later demonstrated the duodenal lesion had cured.

DIGESTIVE ALLOMETRY IN BROILERS SUPPLEMENTED WITH OREGANO FLOUR AS A GROWTH PROMOTER

The objective of the trial was to evaluate the relative weight of different organs and allometric changes of the gastrointestinal tract of broilers, supplemented with oregano leaf meal (HO) as a growth promoter, in mixing proportions with the balanced feed (AB). At 21 days of the starter phase and 42 days of fattening, the weight of the proventriculus, gizzard, duodenum, jejunum and ileum was quantified; as well as, their respective allometric coefficients were determined; in addition, the entire small intestine. A completely randomized experimental design was used, with a total of 208 Ross line chicks distributed in four treatments: T1= 100% balanced feed (AB100%); T2= Balanced feed+0.25% oregano flour (AB+0.25%HO); T3= Balanced feed+0.50% oregano flour (AB+0.50%HO) and T4= Balanced feed+0.75% oregano flour (AB+0.75%HO), with four repetitions, each experimental unit constituted by 13 birds. An analysis of variance was performed on the quantified variables and the average values were compared by Tukey at 5% probability. The concentration of 0.25% HO in combination with BA favored the values obtained for the relative weights at 21 and 42 days of the duodenum, jejunum, ileum, as well as for the entire small intestine. All organs showed slow allometric growth (CA&lt;1) in relation to body weight in the initial and fattening phase, except for the proventriculus, which showed greater growth (CA&gt;1).

A Case of Esophageal Hiatal Hernia Presenting as Upside-Down Stomach Treated Conservatively in Which the Entire Stomach, Transverse Colon, Small Intestine, Pancreas, and Spleen Prolapsed

A Case of Esophageal Hiatal Hernia Presenting as Upside-Down Stomach Treated Conservatively in Which the Entire Stomach, Transverse Colon, Small Intestine, Pancreas, and Spleen Prolapsed

Meckel's Diverticulum Diagnosed by Balloon-Assisted Enteroscopy: A Multicenter Report from the Taiwan Association for the Study of Small Intestinal Diseases (TASSID).

Background and Aims Patients with Meckel's diverticulum (MD) are difficult to preoperatively diagnose because of its endoscopic inaccessibility. Balloon-assisted enteroscopy (BAE) allows endoscopic access to the entire small intestine. The aim of the current study was to investigate patients with MD diagnosed by BAE in Taiwan. Methods We conducted a retrospective, multicenter study of patients with MD who were diagnosed by BAE in Taiwan. The clinical characteristics, endoscopic features, histopathological findings, treatment methods, and outcomes were analyzed. Results A total of 55 patients with MD were enrolled (46 males and 9 females). The mean age at diagnosis was 34.1 years. Overt gastrointestinal bleeding (87.3%) was the primary indication for BAE, followed by abdominal pain (9.1%), suspected small bowel tumor (1.8%), and Crohn's disease follow-up (1.8%). The mean distance between the ileocecal valve and MD was 71.6 cm (regarding diagnostic yields: BAE—100%, capsule endoscopy—40%, Meckel's scan—35.7%, computed tomography—14.6%, small bowel series—12.5%, and angiography—11.1%; regarding endoscopic features of MD: a large ostium—89.1%, a small ostium—7.3%, and a polypoid mass—3.6%). Surgical treatment was performed in 76.4% patients, and conservative treatment was performed in 23.6% patients. The mean length of MD in 42 patients who underwent surgical resection was 5.2 cm (in 43 patients of MD with available histopathology: heterotopic gastric tissue, 42.4%, heterotopic gastric and pancreatic tissues, 7%; heterotopic pancreatic tissue, 4.7%; heterotopic colonic tissue, 2.3%; and a neuroendocrine tumor, 2.3%). Conclusions The current study showed BAE is a very useful modality for detecting MD compared with other conventional modalities.

Value of the ultrasound research in the diagnostic of acute strangulated small bowel obstruction

Purpose. To identify and evaluate the effectiveness of sonographic signs of intestinal ischemia in patients with strangulated small bowel obstruction.Materials and methods. For the period 2017–2019, 115 patients with SIO were treated at the N.V. Sklifosovsky Federal Research Institute of Emergency Medicine. There were 64 women (55.6%) and 51 men (44.4%). The mean age was 62 ± 15 years. In all patients, the diagnosis was verified intraoperatively. All patients underwent ultrasound examination of the abdominal cavity in B-mode with the assessment of blood flow of the intestinal wall in the mode of CDI. Patients were divided on the basis of intraoperative data into 2 groups. The first group: 63 (54.8%) patients with signs of ischemia of the strangulated loop of the intestine. The second group consisted of 21 (18.1%) patients in whom intestinal necrosis was detected. The comparison group included 31 (26.7%) patients with adhesive small bowel obstruction without intestinal strangulation.Results. The most informative signs of ischemia of the strangulated intestine of the loop are infiltrative changes of its mesentery. In the second and third groups 9 (14.3%) and 12 (57.1%) participants, respectively, showed severity of intestinal ischemia, compared with 1 participant (3.2%) in the first group. The next informative criterion is the thickening of more than 0.4 cm and edema of the intestinal wall. In the second and third groups 30 (47.6%) and 14 (66.6%), in the comparison group 4 (12.9%), akinesis of the strangulated loop and paresis of the entire small intestine also directly correlated with intestinal ischemia. The absence of differentiation of intestinal wall layers occurs in (23.8%), the absence of blood flow in the intestinal wall in the CDI mode (19%), gas inclusions in the intestinal wall (4.3%).Conclusion. The assessment of sonographic symptoms allows to diagnose the presence of ischemic changes in the intestinal wall and perform surgery before the development of necrosis in the early period. In cases of late admission of the patient to the hospital, with the onset of intestinal necrosis and the associated erased clinical picture, ultrasound allows to establish indications for surgery before the development of peritonitis.

Developing a model for estimating the activity of colonic microbes after intestinal surgeries.

BackgroundThe large intestine provides a compensatory role in energy recovery when surgical interventions such as extensive small intestinal resections or bypass operations lower the efficiency of nutrient absorption in the upper gastrointestinal (GI) tract. While microorganisms in the colon are known to play vital roles in recovering energy, their contributions remain to be qualified and quantified in the small intestine resection.ObjectiveWe develop a mathematical model that links nutrient absorption in the upper and lower GI tract in two steps.MethodsFirst, we describe the effects of small intestine resection on the ileocecal output (ICO), which enters the colon and provides food for microbes. Second, we describe energy recovered by the colon’s microorganisms via short-chain fatty acid (SCFA) production. We obtain model parameters by performing a least-squares regression analysis on clinical data for subjects with normal physiology and those who had undergone small intestine resection.ResultsFor subjects with their intestines intact, our model provided a metabolizable energy value that aligns well with the traditional Atwater coefficients. With removal of the small intestine, physiological absorption became less efficient, and the metabolizable energy decreased. In parallel, the inefficiencies in physiological absorption by the small intestine are partly compensated by production of short-chain fatty acids (SCFA) from proteins and carbohydrates by microorganisms in the colon. The colon recovered more than half of the gross energy intake when the entire small intestine was removed. Meanwhile, the quality of energy absorbed changed, because microbe-derived SCFAs, not the original components of food, become the dominant form of absorbed energy.ConclusionThe mathematical model developed here provides an important framework for describing the effect of clinical interventions on the colon’s microorganisms.

Organ Growth and Intestinal Functions of Preterm Pigs Fed Low and High Protein Formulas With or Without Supplemental Leucine or Hydroxymethylbutyrate as Growth Promoters.

The goal of enteral nutritional support for infants born preterm or small for gestational age (SGA) is to achieve normal growth and development. Yet, this is difficult to achieve because of intestinal immaturity. Our objective was to determine if birth weight, protein intake, and the growth promoters leucine (10 g/L) or calcium-ß-hydroxy-ß-methylbutryate (HMB; 1.1 g/L) would affect trajectories of intestinal growth and functions and weights of other organs. Preterm pigs were delivered at gestational day 105 (91% of term) and fed for 6 or 7 days isocaloric formulas that differed in protein content (50 g or 100 g protein/L), with and without the growth promoters leucine or HMB. For comparative purposes organ weights were measured within 12 h after delivery for six term pigs of low and six of average birth weights. The responses of intestinal growth and total intestinal brush border membrane carbohydrases to protein level and supplemental leucine were of greater magnitude for preterm pigs of lower birth weight. Forskolin stimulated chloride secretion in the proximal small intestine was lower for pigs fed the low protein milk replacers. Capacities of the entire small intestine to transport glucose (mmol/kg-day) were not responsive to protein level, leucine, or HMB, and did not differ between small and large pigs. Relative organ weights of the small and average weight term pigs were similar, but some differed from those of the preterm pigs suggesting preterm birth and the standards of care used for this study altered the trajectories of development for the intestine and other organs. Although leucine is an effective generalized growth promoter that enhances gut development of small preterm pigs, it does not mitigate compromised neurodevelopment. Our findings using preterm pigs as a relevant preclinical model indicate nutrition support strategies can influence development of some gastrointestinal tract characteristics and the growth of other organs.

Abdominal Cocoon Syndrome: An Extremely Rare Cause of Small Bowel Obstruction

Abdominal cocoon syndrome or encapsulating peritoneal sclerosis is a rare condition causing small bowel obstruction. It is called cocoon syndrome because of the existence of an abnormal membrane that contains part or the entire small intestine. We present a case of a 49-year-old male, presenting to our department with recurrent episodes of obstructive ileus that did not respond to conservative treatment. He underwent exploratory laparotomy and a thick membrane covering the small bowel loops was found. The membrane was excised and sent for pathological examination. Abdominal cocoon syndrome is an acquired condition caused by an inflammatory process that is not yet completely understood. There are many theories for the pathophysiology of the disease. In most cases, the diagnosis is established during surgery. Complete removal of the membrane is the indicated surgical treatment. In mild cases, when the diagnosis is made preoperatively, conservative treatment should be the first choice.

Encapsulating peritoneal sclerosis caused by cell-free and concentrated ascites reinfusion therapy: a case report

BackgroundEncapsulating peritoneal sclerosis (EPS) is a rare condition in which the small intestine is covered by an inflammatory fibrocollagenous membrane; the exact etiology of EPS is unclear. Herein, we report the case of our patient who underwent hemodialysis and cell-free and concentrated ascites reinfusion therapy (CART) and was diagnosed with EPS.Case presentationA 64-year-old Japanese man visited our emergency department with a chief complaint of abdominal pain. He had a medical history of cirrhosis due to hepatitis C for 25 years. He had undergone partial resection of the small intestine 2 years earlier for an incarcerated hernia. One year earlier, he experienced renal failure due to hepatorenal syndrome and started hemodialysis three times a week and CART twice a month. Physical examination of the abdominal wall revealed a lack of peristalsis of the intestinal tract and strong tenderness on palpation.Because hernia of the small intestine was found on computed tomography, we suspected strangulation ileus, requiring emergency operation. When the abdomen was opened, the entire small intestine was found to be wrapped in a fibrous membrane and constricted by it. The patient was diagnosed with EPS; hence, during surgery, the fibrous membrane was excised, resulting in decompression of the intestinal tract and subsequent recovery.ConclusionsEPS is thought to be related to various elements, but no case of EPS induced by CART has been reported to date. EPS should be considered in the differential diagnosis of small bowel obstruction in patients undergoing CART for refractory ascites.

Pyogenic granuloma in small intestine associated with Cowden's disease in a patient with gastrointestinal bleeding:a case report

A 57-year-old female with a history of Cowden's disease was referred to our hospital because of black stool, loss of consciousness, and severe anemia. Upper and lower gastrointestinal endoscopy findings could not confirm the source of hemorrhage. Capsule endoscopy (CE) of the small intestine showed an active exudative hemorrhagic site near the ileum, although a definitive diagnosis was difficult. In a double balloon enteroscopy examination, it was difficult to observe the entire small intestine due to adhesions and the responsible lesion could not be confirmed, even when ink spots were applied to the deepest observation points through the mouth and anus. Hemostasis spontaneously occurred, and then anemia occurred again approximately 1 month later and a second CE examination was performed including passage of an ink stick through the oral side, which revealed an exudative elevated polyp with erosion and a white moss appearance in the ileum. Partial ileal resection was performed and pyogenic granuloma of the small intestine was the diagnosis. We report here a case of pyogenic granuloma of the small intestine associated with Cowden's disease.

BCS Class IV Oral Drugs and Absorption Windows: Regional-Dependent Intestinal Permeability of Furosemide.

Biopharmaceutical classification system (BCS) class IV drugs (low-solubility low-permeability) are generally poor drug candidates, yet, ~5% of oral drugs on the market belong to this class. While solubility is often predictable, intestinal permeability is rather complicated and highly dependent on many biochemical/physiological parameters. In this work, we investigated the solubility/permeability of BCS class IV drug, furosemide, considering the complexity of the entire small intestine (SI). Furosemide solubility, physicochemical properties, and intestinal permeability were thoroughly investigated in-vitro and in-vivo throughout the SI. In addition, advanced in-silico simulations (GastroPlus®) were used to elucidate furosemide regional-dependent absorption pattern. Metoprolol was used as the low/high permeability class boundary. Furosemide was found to be a low-solubility compound. Log D of furosemide at the three pH values 6.5, 7.0, and 7.5 (representing the conditions throughout the SI) showed a downward trend. Similarly, segmental-dependent in-vivo intestinal permeability was revealed; as the intestinal region becomes progressively distal, and the pH gradually increases, the permeability of furosemide significantly decreased. The opposite trend was evident for metoprolol. Theoretical physicochemical analysis based on ionization, pKa, and partitioning predicted the same trend and confirmed the experimental results. Computational simulations clearly showed the effect of furosemide’s regional-dependent permeability on its absorption, as well as the critical role of the drug’s absorption window on the overall bioavailability. The data reveals the absorption window of furosemide in the proximal SI, allowing adequate absorption and consequent effect, despite its class IV characteristics. Nevertheless, this absorption window so early on in the SI rules out the suitability of controlled-release furosemide formulations, as confirmed by the in-silico results. The potential link between segmental-dependent intestinal permeability and adequate oral absorption of BCS Class IV drugs may aid to develop challenging drugs as successful oral products.

Automatic evaluation of degree of cleanliness in capsule endoscopy based on a novel CNN architecture

Capsule endoscopy (CE) is a widely used, minimally invasive alternative to traditional endoscopy that allows visualisation of the entire small intestine. Patient preparation can help to obtain a cleaner intestine and thus better visibility in the resulting videos. However, studies on the most effective preparation method are conflicting due to the absence of objective, automatic cleanliness evaluation methods. In this work, we aim to provide such a method capable of presenting results on an intuitive scale, with a relatively light-weight novel convolutional neural network architecture at its core. We trained our model using 5-fold cross-validation on an extensive data set of over 50,000 image patches, collected from 35 different CE procedures, and compared it with state-of-the-art classification methods. From the patch classification results, we developed a method to automatically estimate pixel-level probabilities and deduce cleanliness evaluation scores through automatically learnt thresholds. We then validated our method in a clinical setting on 30 newly collected CE videos, comparing the resulting scores to those independently assigned by human specialists. We obtained the highest classification accuracy for the proposed method (95.23%), with significantly lower average prediction times than for the second-best method. In the validation of our method, we found acceptable agreement with two human specialists compared to interhuman agreement, showing its validity as an objective evaluation method.

The microbiome can predict mucosal healing in small intestine in patients with Crohn's disease.

Mucosal healing is the main treatment goal for Crohn's disease. In this situation, some patients have difficulty with endoscopic evaluation of the entire small intestine. Crohn's disease is closely associated with the gut microbiota, but the relationship between the microbiome and disease activity in the small intestine remains unclear. We examined the association between the microbiome and endoscopic findings in the small intestine and determined whether the microbiome can predict mucosal healing. The patients with Crohn's disease who were scheduled for capsule or balloon-assisted endoscopy were included in this prospective study. Patients whose entire small intestine was evaluated were divided into two groups based on ulcerative findings. The microbiomes in the fecal samples were analyzed using 16S rRNA sequencing. The 38 enrolled patients were divided into the ulcer group (24) and mucosal healing group (14). The ulcer group exhibited lower α diversity. Six genera, namely Faecalibacterium (P = 0.008), Lachnospira (P = 0.009), Paraprevotella (P = 0.01), Dialister (P = 0.012), Streptococcus (P = 0.025), and Clostridium (P = 0.028) were enriched in the mucosal healing group. A predictive score for mucosal healing was defined using these six genera. The area under the curve was 0.795 and the sensitivity and specificity for predicting mucosal healing were 0.643 and 0.917, respectively. Fecal microbiome is corelated with disease activity in the entire small intestine in Crohn's disease patients. The predictive score proposed by microbiota characteristics was a potential biomarker for mucosal healing in the small intestine.

S1639 Graft vs Host Disease of the Upper and Lower Gastrointestinal Tracts After an Autologous Bone Marrow Transplant: Report of an Unusual Case

INTRODUCTION: Gastrointestinal autologous graft-versus-host disease (GVHD) has been reported in 13% of autologous stem cell transplant (auto-HCT) recipients in comparison to 40% of those who underwent allogenic-HCT. Involvement of both upper and lower GI tracts is a unique phenomenon in auto-GVHD. Herein, we present a case of biopsy-proven GVHD of the duodenum and colon after auto-HCT. CASE DESCRIPTION/METHODS: A 59-year-old male with newly diagnosed multiple myeloma of the lumbar spine received palliative radiation, followed by four cycles of chemotherapy with lenalidomide, bortezomib, and dexamethasone. He subsequently underwent auto-HCT. One month after auto-HCT, he was admitted with fever, nausea, vomiting, early satiety, diarrhea and generalized abdominal pain. Initial laboratory findings included a normal leukocyte count and mild acute kidney injury. Stool testing for infectious etiologies were negative. Additional studies were negative for Epstein–Barr virus, cytomegalovirus (CMV), parvovirus, and his thyroid function was normal. Computed tomography was remarkable for diffuse wall thickening with mucosal hyperenhancement of the entire large and small intestine. Subsequent upper endoscopy revealed atrophic, erythematous, flattened mucosa with petechia in the stomach and diffuse mucosal erythema of the duodenal bulb. Flexible sigmoidoscopy was notable for friable mucosa with altered vasculature, erythema and erosions. Histologic examination of the duodenal mucosa showed villous atrophy with increased number of crypt apoptosis and cryptitis, and active inflammation with the presence of crypt architecture distortion and numerous apoptotic bodies in the crypts of the colon. Immuno-stains for adenovirus and CMV were negative. The constellation of histomorphological features was consistent with GVHD and the patient was subsequently treated with a methylprednisolone taper, which resulted in almost complete resolution of his symptoms. DISCUSSION: GVHD represents an immunocompromised state as it reduces bowel integrity and may lead to severe infections with or without immune suppressive therapy treatment. Certain chemotherapy agents including lenalidomide, inhibit the proliferation and function of regulatory T cells, predisposing patients to GI auto-GVHD. As patients with GI auto-GVHD present with a variety of both upper and lower GI symptoms, we recommend performing endoscopic evaluation of both upper and lower GI tracts to ensure a timely diagnosis.Figure 1.: (A-B) Duodenum. A: Histologic sections of the duodenum shows abnormal villous architecture (arrows) consisting of shortening and widening. Lamina propria (star) cellularity is increased (hematoxylin and eosin stain; original magnification ×40). B: Higher magnification shows the crypts with increased number of apoptosis (arrows) (original magnification ×200). (C-D) Colon. C: Section of the colon shows marked crypt architectural distortion with the presence of acrypt abscesses (arrow). These features are those of chronic colitis with moderate activity (original magnification ×20). D: Colonic crypts show increased number of apoptosis (arrows) (origincal magnification ×200).

Regional Proteomic Quantification of Clinically Relevant Non-Cytochrome P450 Enzymes along the Human Small Intestine.

Current challenges in accurately predicting intestinal metabolism arise from the complex nature of the intestine, leading to limited applicability of available in vitro tools as well as knowledge deficits in intestinal physiology, including enzyme abundance. In particular, information on regional enzyme abundance along the small intestine is lacking, especially for non-cytochrome P450 enzymes such as carboxylesterases (CESs), UDP-glucuronosyltransferases (UGTs), and sulfotransferases (SULTs). We used cryopreserved human intestinal mucosa samples from nine donors as an in vitro surrogate model for the small intestine and performed liquid chromatography tandem mass spectrometry-based quantitative proteomics for 17 non-cytochrome P450 enzymes using stable isotope-labeled peptides. Relative protein quantification was done by normalization with enterocyte marker proteins, i.e., villin-1, sucrase isomaltase, and fatty acid binding protein 2, and absolute protein quantification is reported as picomoles per milligram of protein. Activity assays in glucuronidations and sequential metabolisms were conducted to validate the proteomics findings. Relative or absolute quantifications are reported for CES1, CES2, five UGTs, and four SULTs along the small intestine: duodenum, jejunum, and ileum for six donors and in 10 segments along the entire small intestine (A-J) for three donors. Relative quantification using marker proteins may be beneficial in further controlling for technical variabilities. Absolute quantification data will allow for scaling factor generation and in vivo extrapolation of intestinal clearance using physiologically based pharmacokinetic modeling. SIGNIFICANCE STATEMENT: Current knowledge gaps exist in intestinal protein abundance of non-cytochrome P450 enzymes. Here, we employ quantitative proteomics to measure non-cytochrome P450 enzymes along the human small intestine in nine donors using cryopreserved human intestinal mucosa samples. Absolute and relative abundances reported here will allow better scaling of intestinal clearance.

Lysophosphatidic acid enhances intestinal tuft cell differentiation in Myo5b KO mice independent of Pou2f3

We have reported that adult tamoxifen‐induced, intestine‐specific, Myosin Vb knockout (Myo5b KO) mice recapitulate malabsorption syndrome in a congenital diarrheal disease, microvillus inclusion disease, and that daily treatment with lysophosphatidic acid (LPA) stimulated brush border maturation and sodium/glucose absorption in the Myo5b KO mice. Influence of Myo5b loss and LPA in sensory cell differentiation had not been studied. The present study evaluated the global changes in gene expression following Myo5b loss and LPA treatment, focusing on the differentiation of a nutrient sensor cell lineage, tuft cell. VillinCreERT2;Myo5bflox/flox mice were treated with LPA or vehicle for 4 days after a single tamoxifen injection. Immunostaining on small intestinal sections and whole‐mounted enteroids was used to quantify tuft cell density. RNA sequencing was performed on isolated jejunal epithelial cells. The sections of entire small intestine were analyzed by whole‐slide scanning and digital analysis with Cell Profiler. The frequency of DCLK1+ tuft cell was decreased by 80% with Myo5b loss, whereas enteroendocrine cells showed no difference between Myo5b KO mice and littermate controls. Paneth cell numbers were significantly increased in Myo5b KO, correlating with hyperproliferation in crypts. LPA did not alter the increased Paneth cells or Ki67+ cells. Intraperitoneal LPA treatment re‐established the frequency of tuft cells in Myo5b KO mice, indicating that a tuft cell‐specific differentiation mechanism was activated by LPA. In contrast, enteroids that were generated from VillinCreERT2;Myo5Bflox/flox jejunum had no difference in tuft cell number between hydroxytamoxifen‐treated (iKO) and control enteroids. The disrupted tuft cell differentiation by Myo5b loss was not represented in in vitro system, although microvillus formation was immature in iKO enteroids. RNA‐seq revealed that 844 genes in jejunal epithelial cells were significantly down‐regulated, and 657 genes were up‐regulated by tamoxifen‐induced loss of Myo5b compared to control. Three stem cell transcription factors were significantly increased in KO, whereas two tuft cell‐specific transcription factors (Spib and Pou2f3) were decreased. Epithelial Myo5b loss demonstrated a broad impact on epithelial cell differentiation and maturation. Treatment of Myo5b KO mice with ip LPA up‐regulated only 9 genes and had no effect on the expression of transcription factors, suggesting that LPA may modulate transporter trafficking to stimulate nutrient absorption rather than change the transcription. Myo5b loss abolished the differentiation of a sensory tuft cell, and in vivo treatment with LPA re‐established the tuft cell population independent of Pou2f3 expression. These findings suggest unexplored functions for Myo5b and LPA signaling in cell lineage choice in the intestinal epithelial cells, interacting with non‐epithelial cells.Support or Funding InformationR01 DK48370 and R01 DK70856 and a gift from the Christine Volpe Fund to J.R.G. This work was supported by core resources of the Vanderbilt Digestive Disease Center (P30 DK058404), the Vanderbilt‐Ingram Cancer Center (P30 CA68485), VUMC Digital Histology Shared Resource (supported by a VA Shared Equipment Grant 1IS1BX003097).

Deficiency of Gankyrin in the small intestine is associated with augmented colitis accompanied by altered bacterial composition of intestinal microbiota

BackgroundGankyrin (GK) is an oncoprotein which regulates inflammatory responses and its inhibition is considered as a possible anti-inflammatory therapy for inflammatory bowel disease (IBD).MethodsIn this study, we investigated the role of GK in epithelial cells using mice with intestinal epithelial cell-specific GK deletion in (i) the entire small intestine and colon (Villin-Cre;Gankyrinf/f) and (ii) the distal intestine and colon (Cdx2-Cre;Gankyrinf/f).ResultUnexpectedly, GK-deficiency in the upper small bowel augmented inflammatory activity compared with control mice when colitis was induced with dextran sodium sulfate. Biochemical analyses have revealed GK-deficiency to have caused reduction in the expression of antimicrobial peptides, α-Defensin-5 and -6, in the upper small bowel. Examination of human samples have further confirmed that the reduction of GK expression in the small bowel is associated with colonic involvement in human Crohn’s disease. Through the sequencing of bacterial 16S rRNA gene amplicons, bacteria potentially deleterious to intestinal homeostasis such as Helicobacter japonicum and Bilophila were found to be over-represented in colitis induced Villin-Cre;Gankyrinf/f mice when compared to Gankyrinf/f control mice under the same condition.ConclusionThese results highlight the distinct site dependence of the pro- and anti-inflammatory functions of GK and provide important insights into the pathogenesis of IBD.