Stomach pH Values Research Articles

Eubiotic effect of a dietary potassium diformate (KDF) and probiotic (Lactobacillus acidophilus) on growth, hemato-biochemical indices, antioxidant status and intestinal functional topography of cultured Nile tilapia Oreochromis niloticus fed diet free fishmeal

An 84 days experimental trial was undertaken to examine the influence of potassium diformate (KDF) and Lactobacillus acidophilus and their interaction on growth, biochemical of blood parameters, enzymes of antioxidant response and intestinal topography of Nile tilapia, Oreochromis niloticus, fingerlings fed fishmeal free diets. Six functional diets were formulated to contain two levels of L. acidophilus (0, 1.47 × 107 CFU kg−1), with each level being supplemented with 0, 5 g and 10 g KDF kg−1 diet, respectively. Fingerlings O. niloticus (n = 540; initial weight 4.29 ± 0.06 g) were randomly allocated into six groups (30 fish group−1 in triplicates). The results showed that the best values of growth, feed efficiency and biological parameters were recorded by fish fed diets containing 1.47 × 107 L. acidophilus CFU kg−1 and 10 g kg−1 KDF. Lower pH values in stomach and gut were noted in fish fed diet supplemented with 1.47 × 107 L. acidophilus CFU kg−1 and 10 g kg−1 KDF. Diets supplemented with L. acidophilus, KDF or in combination improved the hemoglobin, red blood cells and white blood cells count with insignificant differences among groups. The activities of serum alanine and aspartate aminotransferase decreased significantly (P < 0.05) by the addition of L. acidophilus and KDF in fish diets. Furthermore, addition of KDF and L. acidophilus significantly (P < 0.05) improved the serum total protein and albumin, but globulin not affected. The lowest value of uric acid was recorded in fish fed 5 g kg−1 KDF without addition of L. acidophilus, while there were no significant (P > 0.05) differences in creatinine content were found among treatments. Diets supplemented with L. acidophilus and/or KDF significantly (P < 0.05) improved phosphorus and calcium content. However, the activities of superoxide dismutase (SOD), total antioxidant capacity (T-AOC) and catalase (CAT) were highest in fish fed diet contained either 5 g or 10 g kg−1 KDF and 1.47 × 107 L. acidophilus CFU kg−1 (D4 and D6). Villi length and width in the middle intestine and number of goblet cell were shown to be promoted in fish fed diets 10 g KDF kg−1 or 10 g kg−1 KDF and 1.47 × 107 L. acidophilus CFU kg−1diet. In conclusion, the administration of a mixture of a probiotic and KDF is beneficial, as it effectively improves the gut morphology and the total antioxidant enzyme activity resulting in an overall enhancement of the fish growth performance.

Preparation and Characterization of a Novel Swellable and Floating Gastroretentive Drug Delivery System (sfGRDDS) for Enhanced Oral Bioavailability of Nilotinib.

Regarding compliance and minimization of side effects of nilotinib therapy, there is a medical need to have a gastroretentive drug delivery system (GRDDS) to enhance the oral bioavailability that is able to administer an optimal dose in a quaque die (QD) or daily manner. In this study, the influence on a swelling and floating (sf) GRDDS composed of a polymeric excipient (HPMC 90SH 100K, HEC 250HHX, or PEO 7000K) and Kollidon® SR was examined. Results demonstrated that PEO 7000K/Kollidon SR (P/K) at a 7/3 ratio was determined to be a basic GRDDS formulation with optimal swelling and floating abilities. MCC PH102 or HPCsssl,SFP was further added at a 50% content to this basic formulation to increase the tablet hardness and release all of the drug within 24 h. Also, the caplet form and capsule form containing the same formulation demonstrated higher hardness for the former and enhanced floating ability for the latter. A pharmacokinetic study on rabbits with pH values in stomach and intestine similar to human confirmed that the enhanced oral bioavailability ranged from 2.65–8.39-fold with respect to Tasigna, a commercially available form of nilotinib. In conclusion, the multiple of enhancement of the oral bioavailability of nilotinib with sfGRDDS could offer a pharmacokinetic profile with therapeutic effectiveness for the QD administration of a reasonable dose of nilotinib, thereby increasing compliance and minimizing side effects.

Casein Compared with Whey Proteins Affects the Organization of Dietary Fat during Digestion and Attenuates the Postprandial Triglyceride Response to a Mixed High-Fat Meal in Healthy, Overweight Men1–3

Background: Postprandial lipemia is a risk factor for cardiovascular disease. The potential impacts of the type/nature of dietary protein on postprandial lipemia and associated dysregulations have been insufficiently investigated.Objective: We investigated the postprandial effect of including in a high-fat meal some milk protein fractions that markedly differ in their physicochemical properties and composition [either casein (CAS), whey protein (WHE), or α-lactalbumin-enriched whey protein (LAC)].Methods: The protein fractions were incorporated as 15% energy in a high-fat meal in a 3-period, crossover postprandial study of 10 healthy overweight men with an elevated waist circumference (>94 cm). We measured postprandial changes in plasma lipids, amino acids, glucose, and oxidative stress markers, vascular function (using pulse contour analysis), and low-grade inflammation (using plasma markers). We also characterized in vitro the meal structures, including the size of the fat globule, and possible changes during digestion.Results: The type of protein did not affect postprandial plasma glucose, amino acids, insulin, or nonesterified fatty acids, but, compared with WHE and LAC, which did not differ, CAS markedly reduced postprandial triglycerides (TGs), achieving a 22 ± 10% reduction in the 6-h area under the curve (P < 0.05). Similar trends were shown for plasma chylomicrons [apolipoprotein (apo)B-48; P < 0.05]. However, there were no significant differences between the meals regarding postprandial oxidative stress (plasma hydroperoxides and malondialdehyde), endothelial dysfunction (salbutamol-induced changes in pulse contour analysis), or low-grade inflammation. In vitro studies showed that when the pH of the meal decreased to stomach pH values, the reduction in the solubility of casein resulted in a phase separation between fat and protein, whereas the proteins in the other meals remained suspended with fat globules.Conclusion: In healthy overweight men, casein has specific physical interactions with fat that affect postprandial TGs, leading to the formation of fewer chylomicrons or an increase in chylomicron clearance. This trial was registered at clinicaltrials.gov as NCT00931151.

Study on interaction between curcumin and pepsin by spectroscopic and docking methods

The interaction between curcumin and pepsin was investigated by fluorescence, synchronous fluorescence, UV–vis absorption, circular dichroism (CD), and molecular docking. Under physiological pH value in stomach, the fluorescence of pepsin can be quenched effectively by curcumin via a combined quenching process. Binding constant (Ka) and binding site number (n) of curcumin to pepsin were obtained. According to the theory of Förster's non-radiation energy transfer, the distance r between pepsin and curcumin was found to be 2.45nm within the curcumin–pepsin complex, which implies that the energy transfer occurs between curcumin and pepsin, leading to the quenching of pepsin fluorescence. Fluorescence experiments also suggest that curcumin is located more closely to tryptophan residues than tyrosine residues. CD spectra together with UV–vis absorbance studies show that binding of curcumin to pepsin results in the extension of peptide strands of pepsin with loss of some β-sheet structures. Thermodynamic parameters calculated from the binding constants at different temperatures reveal that hydrophobic force plays a major role in stabilizing the curcumin–pepsin complex. In addition, docking results support the above experimental findings and suggest the possible hydrogen bonds of curcumin with Thr-77, Thr-218, and Glu-287 of pepsin, which help further stabilize the curcumin–pepsin complex.

A novel biocompatible drug carrier for oral delivery and controlled release of antibiotic drug: loading and release of clarithromycin as an antibiotic drug model

In this work, a novel biocompatible carrier was designed by modification of nanoporous carbon material and synthesized by hydrothermal condensation of d-Fructose, as the carbon source, in the presence of Pluronic® F127, as the surfactant. The prepared material is completely biocompatible and suitable for oral drug delivery. As this nanoporous carbon has surface decorated hydroxyl groups, they are able to react with 3-aminopropyltriethoxysilane agent and produce amino-functionalized nanoporous carbon. The synthesis of amine-modified carbon nanoporous material was confirmed by X-ray powder diffraction, IR spectroscopy, elemental analysis, thermal analysis and nitrogen adsorption analysis. Clarithromycin as an active drug molecule with carbonyl and hydroxyl functional groups in chemical structure was chosen as the drug model and stored in pores of the amine-modified nanoporous carbon. Release of clarithromycin from modified nanoporous carbon was investigated in mouth and stomach pH values. The results showed that this drug carrier can transfer the drug up to stomach without any leak or release. The release time was investigated, and the results showed that the carrier is also successful for the controlled-release delivery.

Assessment of nutritional status and digestive physiology in southern bluefin tuna Thunnus maccoyii fed a modified baitfish diet

Southern bluefin tuna (Thunnus maccoyii) ranching in South Australia is one of the most valuable finfish aquaculture industries in Australia. This industry is currently highly reliant upon the use of baitfish; however commercial pelleted diets for this species are now available. Despite the economic importance of these animals there is a general lack of knowledge regarding the digestive physiology of southern bluefin tuna. Measurement of the digestive enzymes trypsin (T), chymotrypsin (C) and calculation of T:C ratios are particularly useful in the assessment of nutritional status in fish. In this study T and C activities were measured in ranched tuna fed a vitamin (Vit) and vitamin+immunostimulant (Vit+Imm) supplemented baitfish diet for 8weeks. Differences relating to the addition of the supplements were not observed for T, C or T:C ratios suggesting that the supplementation rates did not affect the nutritional status of the tuna or the quality of the baitfish. Trypsin activity plays a key role in the secretion of chymotrypsin and in this study a significant correlation between these enzymes was found. T, C and T:C were not associated with caecum somatic index, caecum pH, caecum temperature, stomach pH or stomach temperature. Although T and C activities are highly sensitive to feeding, activities of these enzymes did not appear to be affected by the presence of baitfish in the stomach. The presence of baitfish did not appear to affect caecum pH, caecum temperature or stomach temperature. Therefore all data were pooled and a significant correlation between caecum and stomach temperature, explained by the endothermic physiology of tuna, was observed. Significantly higher stomach pH values were associated with the presence of baitfish and an inverse relationship between stomach pH and stomach temperature was found in fish with empty stomachs but not those that had eaten. These results are indicative of a digestive strategy which employs maintenance of low stomach pH for rapid digestion of a meal. This study represents the first report of digestive enzyme activities and nutritional status for captive southern bluefin tuna fed a standard and modified baitfish diet. In addition to a better understanding of digestive physiology, these results, in combination with the physiological measures of feeding and digestion, will significantly contribute to the further development of an in vitro digestive model for this species. This model will significantly improve the abilities of the Australian southern bluefin tuna industry to assess the predicted digestibility of commercially produced pelleted diets as well as screen novel dietary ingredients prior to full scale and often commercially expensive in vivo trials.

Effects of pH on mineral-phytate, protein-mineral-phytate, and mineral-fiber interactions. Possible consequences of atrophic gastritis on mineral bioavailability from high-fiber foods.

A common gastrointestinal tract problem afflicting the elderly is that of reduced hydrochloric acid secretion by the stomach mucosa. This results in raised stomach pH values and in reduced activity of the digestive enzyme pepsin, which is responsible for the hydrolysis of dietary proteins to polypeptides. The effects of these alterations of the stomach on the digestion of high-fiber foods and resultant mineral bioavailability have not been defined. This paper reviews the effects of pH on the mineral-phytate, protein-mineral-phytate, and mineral-fiber interactions that would be present in high-fiber foods. Possible consequences of raised stomach pH values on mineral bioavailability from high-fiber foods are discussed.

Gastrointestinal pH measurement in rats: influence of the microbial flora, diet and fasting.

The pH of the rat intestinal tract was decreased by the presence of a microbial flora, but its influence in the forestomach is less clear. Stomach pH values varied according to the amount of food present at the time of measurement. Fasting increased the pH of the gastrointestinal tract in conventional rats but had little effect in germfree rats. In the conventional rat, feeding a purified diet compared with a commercial diet resulted in a lower pH in the forestomach and a higher pH in the caecal contents. Magnesium trisilicate promoted gastric emptying in conventional rats and its antacid effect was observed only in the caecum and colon.