Pepsin Concentration Research Articles

Spatial-temporal mapping of the intra-gastric pepsin concentration and proteolysis in pigs fed egg white gels

While there is a consensus that food structure affects food digestion, the underlying mechanisms remain poorly understood. A previous experiment in pigs fed egg white gels of same composition but different structures evidenced such effect on food gastric disintegration. In this study, we detailed the consequences on intra-gastric pH, pepsin concentration and proteolysis by sampling throughout the stomach over 6 h digestion. Subsequent amino acid absorption was investigated as well by blood sampling. While acidification was almost homogeneous after 6 h digestion regardless of the gel, pepsin distribution never became uniform. Pepsin started to accumulate in the pylorus/antrum region before concentrating in the body stomach beyond 4 h, time from which proteolysis really started. Interestingly, the more acidic and soft gel resulted in a soon (60 min) increase in proteolysis, an earlier and more intense peak of plasmatic amino acids, and a final pepsin concentration three times higher than with the other gels.

Impact of extraction condition on the yield and molecular characteristics of collagen from Asian bullfrog (Rana tigerina) skin

The present study is the first report on collagen extraction as acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC), which could maximize the exploitation of Asian bullfrog (Rana tigerina) skin as an alternative collagen material in food and pharmaceutical fields. Extraction methods for ASC and PSC from Asian bullfrog skin were developed using different concentrations of acetic acid (0.50, 0.75, and 1.00 M) and pepsin (1.00, 2.00, and 3.00% [w/w]). PSCs exhibited a higher extraction yield (22.59%–28.30%) and recovery (22.48%–31.12%) than ASCs. An electrophoretic study revealed that collagens possessed type I collagen. ASC with 0.75 M acetic acid (ASC-0.75) and PSC with 3.00% (w/w) pepsin (PSC-3.00) were selected and analysed on their solubility, molecular characteristics, and amino acid composition. A better solubility with a higher isoelectric point was observed for PSC-3.00 than ASC-0.75. Fourier transform infrared- and circular dichroism-spectra revealed a high-interacted compact structure with a triple helical-structure of the collagen peptides, respectively. A similar amino acid profile with a high imino acid content was observed. Therefore, collagens from Asian bullfrog skin were successfully extracted, where the optimized conditions provided a high yield with less adverse effects on collagen properties and molecular characteristics.

Effects of morphometric and biochemical parameters on collagen and pepsin-solubilized collagen yields of Holothuria tubulosa (Gmelin, 1790) and Holothuria (Roweothuria) poli (Delle Chiaje, 1823)

Due to their unique biochemical composition, sea cucumbers are highly prized marine echinoderm species. One of their most important properties is that they contain a high amount of collagen in their body wall. In this study, the relationship between collagen and pepsin-solubilized collagen yields from Holothuria tubulosa and Holothuria poli and morphometric and biochemical parameters were investigated.
 Collagen yields were in the range of 10.63–16.04% for H. tubulosa and 7.12–13.10% for H. poli. It was determined that they may be related to length, body wall weight, and biochemical composition at different length frequencies. Moreover, maturity may have a direct effect on the yield, as mature specimens were found to have lower content of collagen, whereas immature small specimens contained a higher percentage of collagen. It was found that with increasing pepsin concentration, the PSC yield increased to 1.83–1.89% in H. tubulosa and H. poli, respectively. It was determined that collagen from smaller individuals, which contained more moisture and ash, was likely more susceptible to pepsin hydrolyzation.
 This is the first published study demonstrating that collagen yield of sea cucumbers can vary with length, weight, maturity, and biochemical composition, in addition to species-specific differences.

Analysis of the Factors Affecting Static In Vitro Pepsinolysis of Food Proteins.

In this meta-analysis, we collected 58 publications spanning the last seven decades that reported static in vitro protein gastric digestion results. A number of descriptors of the pepsinolysis process were extracted, including protein type; pepsin activity and concentration; protein concentration; pH; additives; protein form (e.g., ‘native’, ‘emulsion’, ‘gel’, etc.); molecular weight of the protein; treatment; temperature; and half-times (HT) of protein digestion. After careful analysis and the application of statistical techniques and regression models, several general conclusions could be extracted from the data. The protein form to digest the fastest was ‘emulsion’. The rate of pepsinolysis in the emulsion was largely independent of the protein type, whereas the gastric digestion of the native protein in the solution was strongly dependent on the protein type. The pepsinolysis was shown to be strongly dependent on the structural components of the proteins digested—specifically, β-sheet-inhibited and amino acid, leucine, methionine, and proline-promoted digestion. Interestingly, we found that additives included in the digestion mix to alter protein hydrolysis had, in general, a negligible effect in comparison to the clear importance of the protein form or additional treatment. Overall, the findings allowed for the targeted creation of foods for fast or slow protein digestion, depending on the nutritional needs.

Insights into the interaction between chitosan and pepsin by optical interferometry

Polysaccharides and proteins have attracted increasing interest in the fields of biomedicine and green chemical as biocomposites due to their inherent versatility. Here, we used silica colloidal crystal (SCC) films combined with an ordered porous layer interferometry (OPLI) method to investigate the interaction between chitosan and pepsin at different concentrations and pH values in real time. Zeta potential was combined with attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and Fourier transform infrared microscopy (FTIR microscopy) to illustrate the interaction mechanism further. The results showed that the variation and slope of the optical thickness (OT) caused by the Fabry-Perot fringes represent the degree and process of interaction. The protonation of chitosan and the net charge carried by pepsin caused various degrees of electrostatic attraction under different pH values. Meanwhile, the rate and degree of hydrolysis were positively correlated with pepsin concentration. This work results provide a theoretical basis for designing novel composites based on the development of polysaccharides and proteins.

Kinetics of pepsin-induced hydrolysis and the coagulation of milk proteins

Hydrolysis-induced coagulation of casein micelles by pepsin occurs during the digestion of milk. In this study, the effect of pH (6.7-5.3) and pepsin concentration (0.110-2.75 U/mL) on the hydrolysis of κ-casein and the coagulation of the casein micelles in bovine skim milk was investigated at 37°C using reverse-phase HPLC, oscillatory rheology, and confocal laser scanning microscopy. The hydrolysis of κ-casein followed a combined kinetic model of first-order hydrolysis and putative pepsin denaturation. The hydrolysis rate increased with increasing pepsin concentration at a given pH, was pH dependent, and reached a maximum at pH ∼6.0. Both the increase in pepsin concentration and decrease in pH resulted in a shorter coagulation time. The extent of κ-casein hydrolysis required for coagulation was independent of the pepsin concentration at a given pH and, because of the lower electrostatic repulsion between para-casein micelles at lower pH, decreased markedly from ∼73% to ∼33% when pH decreased from 6.3 to 5.3. In addition, the rheological properties and the microstructures of the coagulum were markedly affected by the pH and the pepsin concentration. The knowledge obtained from this study provides further understanding on the mechanism of milk coagulation, occurring at the initial stage of transiting into gastric conditions with high pH and low pepsin concentration.

A magnetic molecularly imprinted nanoparticle assay (MINA) for detection of pepsin

A fully abiotic Molecularly Imprinted Nanoparticle Assay (MINA) is developed for detection of the model protein pepsin. The format of the pepsin assay is based on binding of fluorescent pepsin-specific molecularly imprinted polymer nanoparticles (nanoMIPs) to the magnetic pepsin nanoparticles (MPN) immobilised on magnetic microtiter plate inserts. Competition between free pepsin and immobilised pepsin results in a decrease in nanoMIPs binding to the magnetic inserts, resulting in an increase in fluorescence. Pepsin-specific are prepared using a solid phase synthesis protocol. In order to increase the sensitivity of MINA, two labelling approaches are performed. The first approach uses a fluorescein acrylate included in the monomeric mixture during polymerisation, and the second approach is based on a post-imprinting modification of nanoparticles using the commercial fluorophore AlexaFluor® 647 NHS ester. It is observed that upon increase of free pepsin concentration from 1 μM to 100 μM, fluorescence is increased by 68%. No cross-reactivity in the presence of non-specific protein trypsin is detected. The results show that AlexaFluor-labelled nanoMIPs demonstrate higher performance towards pepsin than fluorescein-labelled nanoMIPs. The novel assay reduces the time and cost of analysis and does not uses any antibodies, eliminating the need for animal-derived reagents. The portfolio of the optimised protocols can potentially be applied for the detection of any other proteins of clinical and environmental interest.

Gastroesophageal reflux disease and salivary pepsin in patients with heterotopic gastric mucosa in the upper esophagus.

Heterotopic gastric mucosa in the upper esophagus (HGMUE) is reported to be related to gastroesophageal reflux disease (GERD). This study investigated the prevalence of GERD and the use of salivary pepsin to diagnose gastroesophageal reflux, especially proximal reflux, in HGMUE patients. One hundred and fifty-three HGMUE patients and 50 healthy volunteers were studied. All subjects took a reflux symptom index questionnaire (RSI); underwent endoscopy, barium esophagogram, high-resolution manometry (HRM), and 24-hour multichannel intraluminal impedance-pH-metry (MII-pH); and salivary pepsin test. Ninety-five (62.1%) HGMUE patients but no control subjects were diagnosed with GERD. The salivary pepsin concentration, RSI score, DeMeester score, acid exposure time (AET), total reflux episodes, proximal acidic reflux episodes, and proximal weakly acidic reflux episodes were significantly higher in the HGMUE group than in the control group (P < 0.05). The salivary pepsin test showed a sensitivity of 85.9% and specificity of 56.9% for diagnosing GERD using the optimal cut-off value of 75ng/mL. One hundred and seven (69.9%) and 46 (30.1%) HGMUE patients were categorized as pepsin (+) and pepsin (-), respectively when 75ng/mL was used as a cut-off value. Male sex, RSI, AET, and proximal acid reflux episodes were positive predictive factors for the occurrence of pepsin (+) in HGMUE patients. GERD, especially GERD with proximal acid reflux and related symptoms, was common in HGMUE patients. The salivary pepsin test could be an additional useful test for testing reflux in HGMUE patients, but it will not replace the MII-pH.

Effect of proton pump inhibitort on salivary pepsin concentration in patients with laryngopharyngeal reflux

Objective:To investigate the effect of proton pump inhibitor（PPI） treatment on salivary pepsin concentration in laryngopharyngeal reflux（LPR）. Methods:152 patients with suspected LPR complaining non-specific symptoms such as foreign body sensation, dry throat, phlegm and other non-specific symptoms were enrolled， in the Second Affiliated Hospital of Xi'an Jiaotong University from August 2019 to December 2020. According to the scores of reflux symptom index（RSI） and reflux finding score（RFS）, all the patients were divided into LPR （+） group and LPR （-） group, RSI （+） group and RSI （-） group, RFS （+） group and RFS （-） group . Patients in the LPR （+） group were reassessed after 1 month of PPI treatment. Saliva samples were collected from all the patients at initial diagnosis and follow-up diagnosis after treatment. The salivary pepsin concentration was determined by enzyme linked immunosorbent assay （ELISA）. The differences of RSI, RFS scores and salivary pepsin concentrations before and after treatment were compared. Results:The median concentration of salivary pepsin in LPR （+） group was significantly higher than that in LPR （-） group, and （73.01 ng/mL vs 25.66 ng/mL, P<0.01）, the median concentration of salivary pepsin in RFS （+） group were significantly higher than that in RFS （-） group（78.00 ng/mL vs 35.79 ng/mL, P<0.01） Furthermore, the median scores of RSI （11.00 vs 7.00, P<0.05） and RFS （9.00 vs 7.00, P<0.01） of LPR （+） patients notably decreased after PPI treatment for 1 month, and the salivary pepsin median concentration was memorably lower than that before treatment（53.60 ng/mL vs 46.49 ng/mL, P<0.05）. Meanwhile, the scores of symptoms such as pharyngeal paraesthesia, heartburn, chest pain, stomachache, and the scores of signs such as false vocal fold, erythema or congestion, vocal fold edema, posterior commissure hypertrophy and thick endolaryngeal mucus were conspicuously lower after treatment than those before treatment（P<0.05）. Conclusion:After 1 month of PPI treatment, the scores of partial symptoms and signs, and the salivary pepsin concentrations of LPR patients decreased significantly, suggesting that pepsin plays an important role in the pathogenesis of LPR, and pepsin may be closely related to the symptoms and signs such as pharyngeal paraesthesia and vocal fold edema.

Cough hypersensitivity in patients with metabolic syndrome: a clinical finding and its possible mechanisms

PurposeTo investigate the changes of cough sensitivity in patients with metabolic syndrome and its possible mechanisms.MethodA total of 29 metabolic syndrome (MetS) patients with OSAHS (group-1), 22 MetS patients without OSAHS (group-2), and 25 healthy controls (group-3) were included. All participants underwent a routine physical examination and completed the gastroesophageal reflux disease questionnaire (GerdQ), and the inflammatory mediator profile were determined. The cough threshold for capsaicin, induced sputum cell count and cell classification, and inflammatory mediators in induced sputum supernatants were compared. The correlation between capsaicin cough sensitivity and various indicators in the MetS population was analyzed.ResultsThe minimum concentration of inhaled capsaicin needed to induce ≥ 5 coughs (C5) was significantly different among three groups (H = 14.393, P = 0.001) and lower for group-1 and group-2 than it for group-3 (P = 0.002, P = 0.005). The percentage of neutrophils in induced sputum and the concentrations of calcitonin gene-related peptide (CGRP), substance P (SP), and interleukin 8 (IL-8) in the sputum supernatant of group-1 and group-2 were significantly higher than those of group-3. Besides, the pepsin concentrations were significantly different among the 3 groups (F = 129.362, P < 0.001), which significantly was highest in group-1 (P < 0.001) and lowest in group-3 (P < 0.001). Triglycerides, AHI, pepsin concentration and BMI were risk factors of increased capsaicin cough sensitivity.ConclusionIncreased capsaicin cough sensitivity in MetS patients is closely related to sleep apnea and gastroesophageal reflux. For patients in MetS patients without OSAHS, gastroesophageal reflux is an important factor for increased capsaicin cough sensitivity. Airway inflammation, especially airway neurogenic inflammation, may also play a role in the pathogenesis of increased capsaicin cough sensitivity.Trial registration The protocol was registered in the Chinese Clinical Trials Register (http://www.chictr.org.cn/) (ChiCTR1800014768). Written informed consent was obtained from all participants before enrollment.

Агрессивные и протективные факторы желудочного сока у больных со стенозом пилородуоденальной зоны язвенного генеза

Цель: оценить агрессивные и протективные свойства желудочного сока у больных со стенозом пилородуоденальной зоны язвенного генеза в зависимости от его степени. Материалы и методы. В отделении хирургии органов пищеварения ГУ «Институт гастроэнтерологии НАМН У­краины» за 2014–2019 годы обследовано 157 больных с различной степенью стеноза пилородуоденальной зоны язвенного генеза. Из них для изучения желудочной кислото- и слизепродукции было отобрано 92 пациента с компенсированным и субкомпенсированным стенозом, среди которых 71 мужчина, 21 женщина в возрасте от 38 до 56 лет, средний возраст (45,3 ± 5,2) года. Больные были разделены на 2 группы в зависимости от степени стеноза: 1 группа — 57 больных с компенсированным стенозом, 2 группа — 35 больных с субкомпенсированным стенозом. Контрольную группу составили 20 практически здоровых лиц. В желудочном содержимом определяли: уровень pH, концентрацию пепсина, гликопротеинов, гексозаминов, фукозы, сиаловых кислот. Результаты. Анализ изучения уровней кислото- и слизепродукции у больных со стенозом пилородуоденальной зоны различной выраженности показал, что у пациентов с субкомпенсированным стенозом отмечалось увеличение частоты гиперацидной секреции на 21,1 % (р &lt; 0,05), существенное повышение уровня пепсина (р &lt; 0,05), уменьшение концентрации общих гликопротеинов (р &lt; 0,05) (за счет существенного уменьшения концентрации фукозы и гексозаминов) по сравнению с пациентами с компенсированным стенозом, которым была более свойственна нормацидная секреция. Полученные нами данные о дисбалансе факторов агрессии и защиты желудочного содержимого позволили нам сформировать различные адаптационно-компенсаторные варианты их соотношения: 1 (гиперреактивный) — одно­временное повышение факторов агрессии и защиты; 2 (компенсаторный) — повышение уровня агрессивных факторов, нормальная концентрация защитных факторов; 3 (декомпенсаторный) — повышение уровня агрессивных факторов, снижение уровня факторов защиты. Выводы. Выявлено, что прогрессирование степени стеноза пилородуоденальной зоны язвенного генеза из компенсированного в субкомпенсированный сопровождается достоверным преобладанием факторов агрессии над факторами защиты желудочного сока и истощением функциональных возможностей слизепродуцирующего аппарата желудка. В результате выделения трех вариантов соотношения факторов агрессии и защиты желудочного сока (гиперреактивный, компенсаторный, декомпенсаторный) установлено, что декомпенсаторный вариант достоверно чаще встречается у пациентов с субкомпенсированным стенозом пилородуоденальной зоны, а значит, риск прогрессирования степени стеноза у таких больных значительно выше по сравнению с другими вариантами соотношений. Обнаруженные варианты соотношений факторов агрессии и защиты у пациентов со стенозом дают возможность дифференцированного подхода к выбору тактики лечения (мини-инвазивного эндоскопического или комбинированного эндо- и лапароскопического метода).

Gastrobodies are engineered antibody mimetics resilient to pepsin and hydrochloric acid

Protein-based targeting reagents, such as antibodies and non-antibody scaffold proteins, are rapidly inactivated in the upper gastrointestinal (GI) tract. Hydrochloric acid in gastric juice denatures proteins and activates pepsin, concentrations of which reach 1 mg/mL in the mammalian stomach. Two stable scaffold proteins (nanobody and nanofitin), previously developed to be protease-resistant, were completely digested in less than 10 min at 100-fold lower concentration of pepsin than found in the stomach. Here we present gastrobodies, a protein scaffold derived from Kunitz soybean trypsin inhibitor (SBTI). SBTI is highly resistant to the challenges of the upper GI tract, including digestive proteases, pH 2 and bile acids. Computational prediction of SBTI’s evolvability identified two nearby loops for randomization, to create a potential recognition surface which was experimentally validated by alanine scanning. We established display of SBTI on full-length pIII of M13 phage. Phage selection of gastrobody libraries against the glucosyltransferase domain of Clostridium difficile toxin B (GTD) identified hits with nanomolar affinity and enzyme inhibitory activity. Anti-GTD binders retained high stability to acid, digestive proteases and heat. Gastrobodies show resilience to exceptionally harsh conditions, which should provide a foundation for targeting and modulating function within the GI tract.

The Impact of Laryngopharyngeal Reflux on Occurrence and Clinical Course of Recurrent Respiratory Papillomatosis.

Laryngopharyngeal reflux (LPR) has been proposed both as a trigger for recurrent respiratory papillomatosis (RRP) onset and as a factor favoring an aggressive clinical course. In this prospective study, 106 participants were recruited within a period of 24 months at the Department of Otorhinolaryngology and Cervicofacial Surgery, University Medical Centre Ljubljana. This study compared a group of RRP patients (N=36) with a group of LPR patients (N=28) and a group of healthy participants (N=42) based on Reflux Symptom Index (RSI), Reflux Finding Scores (RFS), and saliva analyses (pH, pepsin concentration, bile acid concentration, and pepsin enzymatic activity). The RRP group compared to the LPR group showed a statistically significant difference only in RSI and RFS scores, while the RRP group compared to healthy controls showed significantly higher values in all tested parameters (RSI score, RFS, saliva pH, pepsin concentration, bile acids concentration, pepsin enzymatic activity). LPR is common in RRP patients and significantly more prevalent compared to healthy controls. Our results show that saliva analyses are a better office-based tool than RSI questionnaires and RFS scores for diagnosing LPR in RRP patients. 3 Laryngoscope, 132:619-625, 2022.

Narrow-band imaging combined with salivary pepsin to diagnose patients with laryngopharyngeal reflux

Background Laryngopharyngeal reflux (LPR) is a prevalent disease in the ENT outpatient department. Methods of LPR diagnosis differ much. Narrow-band imaging (NBI) and Salivary pepsin-level measurements have been considered as totally new ways for the diagnosis of LPR in recent years. Aim We aimed to identify the specific manifestation of LPR and assess the correlation between NBI views and pepsin levels in LPR diagnosing. Materials and methods 130 Patients enrolled in our study were divided into LPR group and non-LPR group according to the scores of RSI and RFS. All individuals received endoscopic NBI tests and salivary pepsin measurements. NBI views of the larynx were divided into four grades based on the existing descriptive guidelines and our clinical observations, and the correlation between NBI grading and salivary pepsin levels was calculated. Results NBI grading and pepsin levels are significantly correlated with RFS/RSI scores. The diagnostic concentration of salivary pepsin was 33 ng/ml. There was a significant correlation between NBI grading and salivary levels. Conclusions and significance NBI grading system was proved to provide a better diagnostic value in the diagnosis of LPR. There was a possibility that a combination of these two methods might increase the diagnostic accuracy of this disease.

Association of Pepsin With Inflammatory Signaling and Effusion Viscosity in Pediatric Otitis Media.

Otitis media (OM) is a common inflammatory disease spectrum. Cytokine signaling, neutrophil activity, and mucin hypersecretion during recurrent and chronic OM contribute to persistent, viscous middle ear (ME) effusions, hearing loss, and potential for developmental delay. Extraesophageal reflux (EER), specifically pepsin, triggers inflammatory signaling in respiratory mucosa and is associated with OM. The objective of this study was to investigate the association of pepsin with ME inflammatory signaling and the outcomes and examine causality in vitro. Cross-sectional study. ME fluid (MEF) and preoperative audiometric data were collected from 30 pediatric subjects undergoing tympanostomy tube placement for recurrent OM or OM with effusion. MEF viscosity was characterized by the surgeon. Pepsin, inflammatory molecules, and mucin were assayed by enzyme-linked immunosorbent assay (ELISA). ME epithelial primary culture was exposed to 0.1 to 1 mg/ml pepsin at pH 5, 6, and 7 for 30 minutes, and cytokine expression was assayed via qPCR. Pepsin was observed in the MEF of 77% of patients (range 71-2,734 ng/ml). Pepsin correlated with effusion viscosity, interleukins -6 and -8, neutrophil elastase, and mucin 5B (P< .05). Pepsin-negative MEF was more frequently absent of interleukin 8 or mucin 5B (P< .05). Weak acid was generally insufficient to elicit cytokine expression in ME cells in vitro, however, pepsin induced IL6, IL8, and TNF at pH 7 (P< .05) and weak acid (pH 6) facilitated a response at lower pepsin concentration. Pepsin may contribute to inflammatory signaling, persistent viscous effusion, and poorer OM outcomes. 4 Laryngoscope, 132:470-477, 2022.

Diagnostic Value of the PeptestTM in Detecting Laryngopharyngeal Reflux.

Background: The PeptestTM is a non-invasive diagnostic test for measuring the pepsin concentration in saliva, which is thought to correlate with laryngopharyngeal reflux (LPR). The aim of this study was to investigate the diagnostic value of the Peptest in detecting LPR based on 24-h multichannel intraluminal impedance-pH (MII-pH) monitoring using several hypopharyngeal reflux episodes as criterion for LPR. Methods: Patients with suspected LPR were examined with the Reflux Symptom Index (RSI), Reflux Finding Score (RFS), fasting Peptest, and MII-pH monitoring. We calculated the accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the Peptest, RSI, and RFS based on the threshold of one and six hypopharyngeal reflux episodes. Results: Altogether, the data from 46 patients were analyzed. When one hypopharyngeal reflux episode was used as a diagnostic threshold for LPR, the accuracy, sensitivity, specificity, PPV, and NPV were, respectively, as follows: 35%, 33%, 100%, 100%, and 3%, for the Peptest; 39%, 40%, 0%, 95%, and 0%, for the RSI; and 57%, 58%, 0%, 96%, and 0%, for the RFS. The accuracy, sensitivity, specificity, PPV, and NPV of the Peptest for diagnosing gastroesophageal reflux disease (GERD) were 46%, 27%, 63%, 40.0%, and 48%, respectively. Conclusions: A positive Peptest is highly supportive of a pathological LPR diagnosis. However, a negative test could not exclude LPR.

In vitro protein digestibility of enzymatically pre-treated cocoa bean powder using commercial protease

The quality and selling value of cocoa beans could be greatly improved through proper drying of fermented cocoa. Cocoa products are one of the foods that are in great demand by the community, and the fruit could be a source of vegetable protein production. However, the nutritional value of a food is determined by both its total protein content, and the availability of digestible protein. Therefore, the digestibility of this class of food needs to be evaluated. This study was conducted using cocoa beans from the regions of Bali, Jember, Yogyakarta, and Sukabumi, with 2 types of cocoa powder samples namely fat-free, and fat-polyphenols. Furthermore, it used a completely randomized factorial design, consisting of two factors. The first factor was pepsin concentration, comprising of 1000 and 2000 U/ml, while the second was pancreatic activity, consisting of 3 and 8USP. The protein content of the cocoa was tested and the digestibility was determined. The results show that fat-polyphenol-free cocoa powder with 1000 U/mL pepsin and 3USP pancreatic and Jember had the highest protein digestibility with a value of about ± 95%. Furthermore, the results of protein digestibility showed that variations in the concentration of pepsin and pancreatic enzymes had a significant effect on the protein. Therefore, this research shows that interactions between compounds present in foods, like protein-phenolic, could have a significant effect on protein digestibility.

Pepsin and pH of Gastric Juice in Patients With Gastrointestinal Reflux Disease and Subgroups.

The aim of this study was to investigate the pepsin values and pH results of gastric juice among the subtypes of gastroesophageal reflux disease (GERD) and functional heartburn. The major destructive agents of GERD on the esophageal epithelium are gastric acid and pepsin. No precise information about pepsin concentration in gastric juice exists. Ninety patients with GERD, 39 erosive reflux disease (ERD) Los Angeles (LA) grade A/B, 13 ERD LA grade C/D, 19 nonerosive reflux disease (NERD), 8 esophageal hypersensitivity, 11 functional heartburn, and 24 healthy controls were included in the study. During endoscopy gastric juices from the patients were aspirated and their pH readings immediately recorded. Gastric juice samples were analyzed using Peptest, a lateral flow device containing 2 unique human monoclonal antibodies to detect any pepsin present in the gastric juice sample. The highest mean gastric pepsin concentration (0.865 mg/mL) and the lowest median gastric pH (1.4) was observed in the LA grade C/D group compared with the lowest mean gastric pepsin concentration (0.576 mg/mL) and the highest median gastric pH (2.5) seen in the NERD group. Comparing pH, the NERD patient group was significantly higher (P=0.0018 to P=0.0233) when compared with all other GERD patient groups. The basal gastric pepsin level in the healthy control group was comparable to literature values. There was good correlation and a significant linear relationship between the gastric pepsin level and gastric pH within the patient groups. The severity of the GERD disease is related to the lowest pH and the highest pepsin concentration in gastric juice.

Association between gastroesophageal reflux disease and vocal fold polyps.

The aim of this study is to explore the relationship between gastroesophageal reflux disease (GERD) and vocal fold polyps (VFPs).This is a Case-Control study and was performed with the help of The Second Affiliated Hospital of Chongqing Medical University.Twenty-seven patients with VFP and 20 controls without VFP were recruited between May and October 2018. All the subjects underwent a saliva pepsin test, completed the GerdQ questionnaire and 24-hour multichannel intraluminal impedance with pH (24-h MII-pH) monitoring. Twenty-five resected VFP specimens were examined with immunohistochemical (IHC) and double immunofluorescence (IF) staining.The incidence of GERD in the VFP group was significantly higher than that in the control group (P = .003). Patients with VFP had significantly higher GerdQ scores, pepsin concentrations, and pepsin-positive rates (P < .05). Moreover, the number of proximal and upright reflux events was significantly higher in the VFP group (P < .05). The pepsin concentration in saliva showed a significant positive correlation with the pepsin levels in tissues (r2 = 0.50, P = .011). Pepsin and TGF-β1-positive cells were colocalized with CD45RO-positive cells. IHC staining showed that the majority of VFP patients had a positive expression of pepsin (20/25, 80%) and pepsin-positive cells were found in both the squamous epithelium and mesenchymal tissues. IHC staining of TGF-β1 in VFP revealed findings similar to those of pepsin staining.GERD is an important risk factor for VFP. Pepsin may promote the aggregation of immune cells, increase the local cytokines, and promote inflammatory reaction, suggesting a potential new pathogenesis for VFP. The saliva pepsin test is a reliable method for GERD diagnosis.

Correlation of pathogenic effects of laryngopharyngeal reflux and bacterial infection in COME of children

Background Bacteria infection and laryngopharyngeal reflux (LPR) were believed the important pathogenesis of chronic otitis media with effusion (COME). But no study researched the relationship between them on COME. Aims To confirm bacterial could arrive middle ear through LPR and produced acid metabolites to activate the pepsinogen of LPR causing COME. Material and methods Children (65) diagnosed COME with 122 middle ear effusions were included in COME group. Children (22) with congenital/acquired profound deafness with 22 middle ear lavage were included in CI group. Pepsin A concentration in the effusion and lavage fluid were measured. The DNA of the bacteria, IL-8 and TNF-α in the effusion were detected. Results The average concentration of pepsin A in the effusions and lavage were 176.65 ± 242.09 and 19 ng/ml. Bacterial infection rates were 75.76% and 24.24% in the pepsin A(+) and pepsin A(−) patients. In the bacterial (+), the patients of pepsin A(+) was 4.33 times higher than those of pepsin A(−). TNF-α in pepsin A(+) was higher than that in pepsin A(−). TNF-α and IL-8 were higher in bacteria(+) than those of bacteria(−). Conclusions Bacterial infection and LPR might act in synergy in the pathogenesis of COME. Significance First time to propose LPR and bacterial infection might work synergistically to cause COME.