Lactose intolerance: An update on its pathogenesis, diagnosis, and treatment.

Lactose intolerance has a high prevalence worldwide, ranging between 57% and 65%. It is caused by a reduction or loss of the activity of the intestinal enzyme lactase-phlorizin hydrolase, responsible for the digestion of lactose. This alteration determines an increased osmotic load in the small intestine and the fermentation of lactose by the bacterial flora, which leads to a high production of short-chain fatty acids and gas. This is followed by the onset of abdominal pain, diarrhea, and flatulence. In addition to these problems, it was found that subjects with lactose intolerance have an increased risk of developing various extra-intestinal diseases, including cancers. The diagnosis is essential to undertake an adequate treatment and, for this purpose, different methods have been tested. These include genetic test, hydrogen breath test (HBT), quick lactase test, and lactose tolerance test. HBT is the most used method because it is non-invasive, inexpensive, and highly sensitive and specific, as well as easy to perform. In clinical practice, the other methods are mainly used as HBT integration tests. There are also many therapeutic options. An appropriate intervention concerns the dietetic style, such as the consumption of lactose-free foods, but with nutritional characteristics comparable to dairy products. Other valid choices are represented by the use of exogenous enzymes, probiotics, prebiotics, the selection of milk containing specific types of beta-caseins. This review is intended to illustrate the diagnostic methods currently available and the possible therapeutic options for lactose intolerance.

Halloysite nanotube-embedded microparticles for intestine-targeted co-delivery of biopharmaceuticals.

Microparticles (MPs) with pH-responding macropores have recently proved their significance for the delivery of vulnerable biomolecules for oral drug administration. The previous MP systems were proven to provide enhanced protection against the gastric environment, however, their application is hindered due to insufficient loading efficiencies and deficient penetration capabilities of encapsulated drugs across the mucus barrier. Here, we report a new co-delivery approach based on amine-functionalized halloysite nanotube (HNT)-embedded MPs (amine-HNT-MPs) with pH-responding macropores specifically designed to deal with the mucus barrier at the absorption site. The mean diameter and polydispersity index of the pored MPs were measured by a particle size analyzer to be 37.6 ± 1.3 µm and 1.15, respectively. The drug loading capacity of the co-delivery system was shown to be 50-times higher than previously reported pored MPs. Fluorescence microscopy analysis of sulforhodamine B (into a hollow interior of HNTs)/ fluorescent nanoparticles (into a hollow interior of MPs)-encapsulated MPs confirmed biphasic release behavior due to pH-dependent pore closing/opening in the simulated gastrointestinal (GI) digestive conditions. To verify the protective effect of the co-delivery system, bromelain and lactase were loaded into HNTs and MPs, respectively, and found to exhibit 94.5 ± 3.3% (bromelain) and 70 ± 14.1% (lactase) functional activity in simulated GI tract conditions. The considerable improvement in the stability of the encapsulated enzymes against gastric conditions are attributed to the efficient pore sealing of the co-delivery system after the encapsulation of enzymes and maintenance of these closed pores in the gastric environment. Furthermore, the mucolytic enzyme (i.e. bromelain)-encapsulated co-delivery system was found to enhance mucopenetration of the encapsulated drug from histological analysis using ex vivo porcine intestine tissue. Therefore, the new microencapsulation design proposed in this study provides a promising solution to the major issues hampering the wide-spread application of MPs in the development of oral drug formulations for biopharmaceuticals and vaccines.

Physicochemical and sensory properties of milk supplemented with lactase microcapsules coated with enteric coating materials.

In this paper, we report the physicochemical and sensory properties of milk supplemented with a powder of microencapsulated lactase. The core material was lactase (ß-galactosidase), the primary coating material was medium-chain triglyceride (MCT), and the secondary (enteric) coating material was either hydroxypropyl methylcellulose phthalate (HPMCP) or shellac, comparing both against market milk as a control. The physicochemical properties of both types of microcapsules were analyzed, including the particle size, zeta potential, and in vitro release behavior. To survey the stability of the microcapsules in milk during storage, we studied the residual lactose content and pH. Furthermore, to determine the properties of milk supplemented with the microcapsules, changes in color and sensory properties were evaluated during storage. The particle sizes (volume-weighted mean; D[4,3]) of the microcapsules coated with HPMCP or shellac were 2,836 and 7,834 nm, respectively, and the zeta potential of the capsules coated with shellac was higher than the zeta potential of those coated with HPMCP. The pH levels of milk supplemented with the lactase microcapsules were similar to those of the control (unsupplemented market milk); however, for milk supplemented with HPMCP-coated microcapsules, the pH was slightly lower. The core material, lactase, was released from the microcapsules during 12-d storage, and 18.82 and 35.09% of lactose was hydrolyzed in the samples for HPMCP- and shellac-coated microcapsules, respectively. The sensory characteristics of milk containing microcapsules coated with HPMCP did not show significant differences from the control, in terms of sweetness or off-taste, until 8 d of storage. However, shellac-coated microcapsules showed significant difference in sweetness and off-taste at d 8 and 6 of storage, respectively. The color of milk containing HPMCP-coated microcapsules did not show a significant difference during storage. However, that containing shellac-coated microcapsules was somewhat higher in color values than others. In particular, it showed significance from 0 to 4 d storage in L* and C* values. In conclusion, a powder of lactase microcapsules coated with HPMCP can be suitable as a supplement for milk.

Influência de diferentes concentrações de enzima lactase sobre a hidrólise da lactose em leite pasteurizado e seus aspectos físico-químicos / Influence of different concentrations of lactase enzymes on a lactose hydrolysis in pasteurized milk and their physico-chemical aspects

A lactose é o carboidrato predominante no leite e responsável por diversas reações importantes no processamento de derivados lácteos. Contudo, também é responsável pelo desconforto trazido às pessoas intolerantes à este açúcar. A indústria vem se aprimorando para retirar ou reduzir a lactose dos produtos lácteos. Este trabalho objetivou testar o método de hidrólise para reduzir o teor de lactose no leite de vaca pasteurizado utilizando três concentrações de enzima diferentes e observar as propriedades físico-químicas decorrentes do processo. Os três tratamentos foram submetidos a 30ºC por tempo suficiente para que a crioscopia de cada um estabilizasse. Os resultados demonstraram que a enzima testada foi eficaz para reduzir o teor de lactose no leite em até aproximadamente 93%, mas nenhum dos tratamentos se enquadraria na legislação vigente como “zero lactose”. As propriedades físico-químicas mantiveram-se dentro dos limites da legislação para leite pasteurizado.

Dietary modifications for infantile colic.

BACKGROUND: Infantile colic is typically defined as full-force crying for at least three hours per day, on at least three days per week, for at least three weeks. This condition appears to be more frequent in the first six weeks of life (prevalence range of 17% to 25%), depending on the specific location reported and definitions used, and it usually resolves by three months of age. The aetiopathogenesis of infantile colic is unclear but most likely multifactorial. A number of psychological, behavioural and biological components (food hypersensitivity, allergy or both; gut microflora and dysmotility) are thought to contribute to its manifestation. The role of diet as a component in infantile colic remains controversial. OBJECTIVES: To assess the effects of dietary modifications for reducing colic in infants less than four months of age. SEARCH METHODS: In July 2018 we searched CENTRAL, MEDLINE, Embase , 17 other databases and 2 trials registers. We also searched Google, checked and handsearched references and contacted study authors. SELECTION CRITERIA: Randomised controlled trials (RCTs) and quasi-RCTs evaluating the effects of dietary modifications, alone or in combination, for colicky infants younger than four months of age versus another intervention or placebo. We used specific definitions for colic, age of onset and the methods for performing the intervention. We defined 'modified diet' as any diet altered to include or exclude certain components. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. Our primary outcome was duration of crying, and secondary outcomes were response to intervention, frequency of crying episodes, parental/family quality of life, infant sleep duration, parental satisfaction and adverse effects. MAIN RESULTS: We included 15 RCTs involving 1121 infants (balanced numbers of boys and girls) aged 2 to 16 weeks. All studies were small and at high risk of bias across multiple design factors (e.g. selection, attrition). The studies covered a wide range of dietary interventions, and there was limited scope for meta-analysis. Using the GRADE approach, we assessed the quality of the evidence as very low.Low-allergen maternal diet versus a diet containing known potential allergens: one study (90 infants) found that 35/47 (74%) of infants responded to a low-allergen maternal diet, compared with 16/43 (37%) of infants on a diet containing known potential allergens.Low-allergen diet or soy milk formula versus dicyclomine hydrochloride: one study (120 infants) found that 10/15 (66.6%) breastfed babies responded to dicyclomine hydrochloride, compared with 24/45 (53.3%) formula-fed babies. There was little difference in response between breastfed babies whose mother changed their diet (10/16; 62.5%) and babies who received soy milk formula (29/44; 65.9%).Hydrolysed formula versus standard formula: two studies (64 infants) found no difference in duration of crying, reported as a dichotomous outcome: risk ratio 2.03, 95% confidence interval (CI) 0.81 to 5.10; very low-quality evidence. The author of one study confirmed there were no adverse effects. One study (43 infants) reported a greater reduction in crying time postintervention with hydrolysed formula (104 min/d, 95% CI 55 to 155) than with standard formula (3 min/d, 95% CI -63 to 67).Hydrolysed formula versus another hydrolysed formula: one study (22 infants) found that two types of hydrolysed formula were equally effective in resolving symptoms for babies who commenced with standard formula (Alimentum reduced crying to 2.21 h/d (standard deviation (SD) 0.40) and Nutramigen to 2.93 h/d (SD 0.70)).Hydrolysed formula or dairy- and soy-free maternal diet versus addition of parental education or counselling: one study (21 infants) found that crying time decreased to 2.03 h/d (SD 1.03) in the hydrolysed or dairy- and soy-free group compared with 1.08 h/d (SD 0.7) in the parent education or counselling group, nine days into the intervention.Partially hydrolysed, lower lactose, whey-based formulae containing oligosaccharide versus standard formula with simethicone: one study (267 infants) found that both groups experienced a decrease in colic episodes (secondary outcome) after seven days (partially hydrolysed formula: from 5.99 episodes (SD 1.84) to 2.47 episodes (SD 1.94); standard formula: from 5.41 episodes (SD 1.88) to 3.72 episodes (SD 1.98)). After two weeks the difference between the two groups was significant (partially hydrolysed: 1.76 episodes (SD 1.60); standard formula: 3.32 episodes (SD 2.06)). The study author confirmed there were no adverse effects.Lactase enzyme supplementation versus placebo: three studies (138 infants) assessed this comparison, but none reported data amenable to analysis for any outcome. There were no adverse effects in any of the studies.Extract of Foeniculum vulgare, Matricariae recutita, and Melissa officinalis versus placebo: one study (93 infants) found that average daily crying time was lower for infants given the extract (76.9 min/d (SD 23.5), than infants given placebo (169.9 min/d (SD 23.1), at the end of the one-week study. There were no adverse effects.Soy protein-based formula versus standard cows' milk protein-based formula: one study (19 infants) reported a mean crying time of 12.7 h/week (SD 16.4) in the soy formula group versus 17.3 h/week (SD 6.9) in the standard cows' milk group, and that 5/10 (50%) responded in the soy formula group versus 0/9 (0%) in the standard cows' milk group.Soy protein formula with polysaccharide versus standard soy protein formula: one study (27 infants) assessed this comparison but did not provide disaggregated data for the number of responders in each group after treatment.No study reported on our secondary outcomes of parental or family quality of life, infant sleep duration per 24 h, or parental satisfaction. AUTHORS' CONCLUSIONS: Currently, evidence of the effectiveness of dietary modifications for the treatment of infantile colic is sparse and at significant risk of bias. The few available studies had small sample sizes, and most had serious limitations. There were insufficient studies, thus limiting the use of meta-analysis. Benefits reported for hydrolysed formulas were inconsistent.Based on available evidence, we are unable to recommend any intervention. Future studies of single interventions, using clinically significant outcome measures, and appropriate design and power are needed.

Application of a commercial digestive supplement formulated with enzymes and probiotics in lactase non-persistence management.

Strategies to avoid lactose malabsorption, which affects 70% of the world's population, are focused on the restriction of milk and dairy products or the use of non-human ß-galactosidases or probiotics endowed with ß-galactosidase activity added at mealtime. Our evaluation of a commercial blend of probiotics and enzymes (protease, lactase, lipase and amylase) and its potential application in lactase non-persistence management is described in this work. Recommended amounts (460-1000 mg) of the commercial probiotics-enzyme blend were shown to be adequate for performing in vitro lactose hydrolysis in standard solutions (0.25-5%) and commercial dairy products, namely milks (5% lactose) and yogurts (3% lactose), reaching hydrolysis values between 44 and 96%. According to these percentages, the use of the enzymatic preparation would guarantee the intake of less than 12 g, the recommendation of the EFSA for lactose intolerance. Furthermore, formation of prebiotic galactooligosaccharides was also detected, increasing the potential benefits of the enzymatic preparation in the gastrointestinal system.

Encapsulation, protection, and delivery of bioactive proteins and peptides using nanoparticle and microparticle systems: A review.

There are many examples of bioactive proteins and peptides that would benefit from oral delivery through functional foods, supplements, or medical foods, including hormones, enzymes, antimicrobials, vaccines, and ACE inhibitors. However, many of these bioactive proteins are highly susceptible to denaturation, aggregation or hydrolysis within commercial products or inside the human gastrointestinal tract (GIT). Moreover, many bioactive proteins have poor absorption characteristics within the GIT. Colloidal systems, which contain nanoparticles or microparticles, can be designed to encapsulate, retain, protect, and deliver bioactive proteins. For instance, a bioactive protein may have to remain encapsulated and stable during storage and passage through the mouth and stomach, but then be released within the small intestine where it can be absorbed. This article reviews the application of food-grade colloidal systems for oral delivery of bioactive proteins, including microemulsions, emulsions, nanoemulsions, solid lipid nanoparticles, multiple emulsions, liposomes, and microgels. It also provides a critical assessment of the characteristics of colloidal particles that impact the effectiveness of protein delivery systems, such as particle composition, size, permeability, interfacial properties, and stability. This information should be useful for the rational design of medical foods, functional foods, and supplements for effective oral delivery of bioactive proteins.

Oral administration of exogenous lactase in tablets for patients diagnosed with lactose intolerance due to primary hypolactasia / Administração oral de lactase exógena em comprimidos em pacientes portadores de intolerância à lactose devido à hipolactasia primária

ABSTRACT Background Primary hypolactasia is a common condition where a reduced lactase activity in the intestinal mucosa is present. The presence of abdominal symptoms due to poor absorption of lactose, which are present in some cases, is a characteristic of lactose intolerance. , Objective Evaluate the efficacy of a product containing exogenous lactase in tablet form compared to a reference product with proven effectiveness in patients with lactose intolerance. Methods Multicentre, randomized, parallel group, single-blind, comparative non-inferiority study. One hundred twenty-nine (129) adult lactose intolerance patients with hydrogen breath test results consistent with a diagnosis of hypolactasia were randomly assigned to receive the experimental product (Perlatte(r) - Eurofarma Laboratórios S.A.) or the reference product (Lactaid(r) - McNeilNutritionals, USA) orally (one tablet, three times per day) for 42 consecutive days. Results Data from 128 patients who actually received the studied treatments were analysed (66 were treated with the experimental product and 62 with the reference product). The two groups presented with similar baseline clinical and demographic data. Mean exhaled hydrogen concentration tested at 90 minutes after the last treatment (Day 42) was significantly lower in the experimental product treated group (17±18 ppm versus 34±47 ppm) in the per protocol population. The difference between the means of the two groups was -17 ppm (95% confidence interval [95% CI]: -31.03; -3.17). The upper limit of the 95% CI did not exceed the a priori non-inferiority limit (7.5 ppm). Secondary efficacy analyses confirmed that the treatments were similar (per protocol and intention to treat population). The tolerability was excellent in both groups, and there were no reports of serious adverse events related to the study treatment. Conclusion The experimental product was non-inferior to the reference product, indicating that it was an effective replacement therapy for endogenous lactase in lactose intolerance patients.

RESUMO Contexto A hipolactasia primária é uma condição muito frequente na qual há redução da atividade da lactase na mucosa intestinal.A presença de sintomas abdominais devidos à má absorção da lactose presente em alguns casos caracteriza a intolerância à lactose. Objetivo Avaliar a eficácia de um produto contendo lactase exógena em comprimidos comparativamente a de um produto comparador com eficácia comprovada em pacientes portadores de intolerância à lactose. Métodos Estudo multicêntrico, randomizado, de grupos paralelos, com investigador cego, comparativo de não-inferioridade. Cento e vinte e nove (129) pacientes adultos portadores de intolerância à lactose e teste do hidrogênio no ar expirado compatível com o diagnóstico de hipolactasia foram randomizados para receber o produto experimental (Perlatte(r) - Eurofarma Laboratórios S.A.) ou o produto comparador (Lactaid(r) - McNeil Nutritionals, EUA), por via oral (um comprimido, três vezes ao dia), durante 42 dias consecutivos. Resultados Os dados dos 128 pacientes que efetivamente receberam o tratamento do estudo foram avaliados (66 tratados com o produto experimental e 62 com o produto comparador). Os dois grupos se mostraram homogêneos quanto aos dados demográficos e clínicos basais. A média da concentração do hidrogênio expirado aos 90 minutos no teste realizado ao final do tratamento (Dia 42) foi significativamente menor no grupo tratado com o produto experimental (17±18 ppm versus 34±47 ppm na população por protocolo). A diferença entre as médias dos dois grupos foi de -17 ppm (intervalo de confiança de 95% [IC95%]: -31,03; -3,17). O limite superior do IC95% não ultrapassou a margem de não-inferioridade estipulada a priori (7,5 ppm). As análises secundárias de eficácia confirmaram a semelhança entre os tratamentos (populações por protocolo e com intenção de tratamento). A tolerabilidade foi excelente em ambos os grupos e não houve relato de eventos adversos graves relacionados ao produto. Conclusão O produto experimental se mostrou não-inferior ao produto comparador, indicando sua eficácia no tratamento substitutivo da lactase endógena em pacientes portadores de intolerância à lactose.

ORAL ADMINISTRATION OF EXOGENOUS LACTASE IN TABLETS FOR PATIENTS DIAGNOSED WITH LACTOSE INTOLERANCE DUE TO PRIMARY HYPOLACTASIA.

Background: Primary hypolactasia is a common condition where a reduced lactase activity in the intestinal mucosa is present. The presence of abdominal symptoms due to poor absorption of lactose, which are present in some cases, is a characteristic of lactose intolerance. Objective: Evaluate the efficacy of a product containing exogenous lactase in tablet form compared to a reference product with proven effectiveness in patients with lactose intolerance. Methods: Multicentre, randomized, parallel group, single-blind, comparative non-inferiority study. One hundred twenty-nine (129) adult lactose intolerance patients with hydrogen breath test results consistent with a diagnosis of hypolactasia were randomly assigned to receive the experimental product (Perlatte(r) - Eurofarma Laboratórios S.A.) or the reference product (Lactaid(r) - McNeilNutritionals, USA) orally (one tablet, three times per day) for 42 consecutive days. Results: Data from 128 patients who actually received the studied treatments were analysed (66 were treated with the experimental product and 62 with the reference product). The two groups presented with similar baseline clinical and demographic data. Mean exhaled hydrogen concentration tested at 90 minutes after the last treatment (Day 42) was significantly lower in the experimental product treated group (17±18 ppm versus 34±47 ppm) in the per protocol population. The difference between the means of the two groups was -17 ppm (95% confidence interval [95% CI]: -31.03; -3.17). The upper limit of the 95% CI did not exceed the a priori non-inferiority limit (7.5 ppm). Secondary efficacy analyses confirmed that the treatments were similar (per protocol and intention to treat population). The tolerability was excellent in both groups, and there were no reports of serious adverse events related to the study treatment. Conclusion: The experimental product was non-inferior to the reference product, indicating that it was an effective replacement therapy for endogenous lactase in lactose intolerance patients.

[THERAPY OF TRANSIENT LACTASE INSUFFICIENCY OF CHILDREN IN PECTORAL AGE].

Thus, we have discovered that the children of the first half-year of life have different degrees of severity of transient lactase insufficiency basing on the results of hydrogen respiratory test. It was set that the starting dose of enzyme lactase must depend on the degree of severity of displays of transient lactase insufficiency, taking into account the indexes of hydrogen respiratory test.

Enzyme activity of ß-galactosidase from Kluyveromyces lactis and Aspergillus oryzae on simulated conditions of human gastrointestinal system / Atividade de ß-galactosidase de Kluyveromyces lactis e Aspergillus oryzae, em condições simuladas do sistema gastrintestinal humano

An alternative to relieve the symptoms of lactose intolerance is the intake of the enzyme ?-galactosidase in pharmaceutical dosage forms. The ability of ?-galactosidase produced by Kluyveromyces lactis and Aspergillus oryzae to hydrolyze lactose in simulated conditions of the human gastrointestinal tract was investigated. The experiment was carried out in the optimum temperature for each enzyme activity, 40 and 55°C, respectively, and at the normal human body temperature (37°C) at concentrations of 1.5, 3.0, and 5.0 g/L (enzyme from A. oryzae) or mL/L (enzyme from K. lactis). Both enzymes were completely inactivated under simulated gastric conditions (pH 2). When the enzymes were subjected to simulated small intestine conditions (pH 7.4), lactose hydrolysis has occurred, but at 37°C the percentage was lower than that under the optimal temperatures. At concentrations of 1.5, 3.0, and 5.0 mL/L the enzyme from K. lactis hydrolyzed 76.63%, 88.91% and 94.80% of lactose at 40°C, and 55.99%, 80.91% and 81.53% at 37°C, respectively. In contrast, the enzyme from A. oryzae hydrolyzed 7.11%, 16.18% and 21.29% at 55°C, and 8.4%, 11.85% and 16.43% at 37°C. It was observed that under simulated intestinal conditions, the enzyme from K. lactis was more effective on lactose hydrolysis as compared to the enzyme from A. oryzae. Considering the findings of this study, it is extremely necessary to use an enteric coating on ?-galactosidase capsules so that this enzyme is released only in the small intestine, which is its site of action, thus not suffering the action of the stomach pH.(AU)

Uma das alternativas para amenizar os sintomas da intolerância à lactose é a ingestão de ?-galactosidase em formas farmacêuticas. Neste trabalho avaliou-se a capacidade de hidrólise de ?-galactosidase produzida por Kluyveromyces lactis e Aspergillus oryzae simulando as condições do trato gastrintestinal humano. O teste foi realizado nas temperaturas ótimas de ação para cada enzima, 40 e 55°C, respectivamente, e na temperatura corpórea humana (37°C), nas concentrações de 1,5; 3,0 e 5,0 g/L para a enzima de Aspergillus oryzae ou mL/L para a de Kluyveromyces lactis. Na simulação da condição estomacal humana (pH 2), ambas enzimas foram totalmente inativadas. Quando as enzimas foram submetidas às condições simuladas do intestino delgado (pH 7,4), observou-se hidrólise da lactose, porém, a 37°C, a porcentagem foi menor do que a observada nas temperaturas ótimas de cada enzima. A enzima de K. lactis nas concentrações de 1,5; 3,0 e 5,0 mL/L apresentou hidrólise de 76,63%, 88,91% e 94,80% a 40°C e 55,99%, 80,91% e 81,53%, a 37°C, respectivamente. Nas concentrações 1,5; 3,0 e 5,0 g/L, a porcentagem de hidrólise pela enzima de A. oryzae a 55°C foi de 7,11%, 16,18% e 21,29%. Para esta enzima, nessas concentrações, a hidrólise obtida a 37°C foi 8,4%, 11,85% e de 16,43%. Sob condições intestinais simuladas, a enzima de K. lactis apresentou maior eficiência na hidrólise da lactose quando comparada à enzima de A. oryzae. Considerando-se as etapas avaliadas neste estudo, observa-se que é extremamente necessário o uso de um revestimento entérico em cápsulas de ?-galactosidase, para que esta enzima seja liberada somente no intestino delgado, seu local de ação, não sofrendo, portanto, a ação do pH estomacal.(AU)

Novel epoxy activated hydrogels for solving lactose intolerance.

"Lactose intolerance" is a medical problem for almost 70% of the world population. Milk and dairy products contain 5-10% w/v lactose. Hydrolysis of lactose by immobilized lactase is an industrial solution. In this work, we succeeded to increase the lactase loading capacity to more than 3-fold to 36.3 U/g gel using epoxy activated hydrogels compared to 11 U/g gel using aldehyde activated carrageenan. The hydrogel's mode of interaction was proven by FTIR, DSC, and TGA. The high activity of the epoxy group was regarded to its ability to attach to the enzyme's -SH, -NH, and -OH groups, whereas the aldehyde group could only bind to the enzyme's -NH2 group. The optimum conditions for immobilization such as epoxy chain length and enzyme concentration have been studied. Furthermore, the optimum enzyme conditions were also deliberated and showed better stability for the immobilized enzyme and the Michaelis constants, K m and V max, were doubled. Results revealed also that both free and immobilized enzymes reached their maximum rate of lactose conversion after 2 h, albeit, the aldehyde activated hydrogel could only reach 63% of the free enzyme. In brief, the epoxy activated hydrogels are more efficient in immobilizing more enzymes than the aldehyde activated hydrogel.

Effects of exogenous lactase administration on hydrogen breath excretion and intestinal symptoms in patients presenting lactose malabsorption and intolerance.

OBJECTIVE: To establish whether supplementation with a standard oral dose of Beta-Galactosidase affects hydrogen breath excretion in patients presenting with lactose malabsorption. METHODS: Ninety-six consecutive patients positive to H2 Lactose Breath Test were enrolled. Mean peak H2 levels, the time to reach the peak H2, the time to reach the cut-off value of 20 ppm, the cumulative breath H2 excretion, the areas under the curve, and a Visual Analogical 10-point Scale for symptoms were calculated. Genotyping of the C/T-13910 variant was carried out. RESULTS: Following the oral administration of Beta-Galactosidase, in 21.88% of the cases, H2 Lactose Breath Test became negative (Group A), while mean peak H2 levels (74.95 ppm versus 7.85), P < 0.0000, in 17.71% (Group B) were still positive, with the H2 level 20 ppm above the baseline, but the peak H2 levels were significantly lower than those observed at the baseline test (186.7 ppm versus 66.64), P < 0.0000, while in 60.41% (Group C) they were still positive with the peak H2 levels similar to those observed at the baseline test (94.43 versus 81.60 ppm). All 96 individuals tested presented the C/C-13910 genotype nonpersistence. CONCLUSIONS: The response to oral administration of Beta-Galactosidase in patients with symptoms of lactose malabsorption presents a significant variability.

Sucrose produces withdrawal and dopamine-sensitive reinforcing effects in planarians.

Sucrose produces physical dependence and reinforcing effects in rats. We hypothesized that similar effects could be demonstrated in planarians, the earliest animal with a centralized nervous system. We used two assays, one that quantifies withdrawal responses during drug absence as a reduction in motility and another that quantifies reinforcing effects using a conditioned place preference (CPP) design. In withdrawal experiments, planarians exposed to sucrose (1%) for 60 min and then tested in water for 5 min displayed reduced motility compared to water controls. Acute or continuous sucrose (1%) exposure did not affect motility. CPP experiments used a biased design to capitalize upon planarians' natural preference for the dark (pretest, sucrose conditioning in the light, posttest). Planarians conditioned with sucrose (1%) displayed a greater preference shift than sucrose-naïve planarians. Glucose (0.1, 1%), but not the non-digestible disaccharide lactulose (0.1, 1%), also produced a greater preference shift than water-exposed planarians. Development of sucrose-induced CPP was inhibited when sucrose (1%) conditioning was conducted in combination with dopamine receptor antagonists SCH 23390 (1 µM) or sulpiride (1 µM). These results suggest that the rewarding and reinforcing effects of sugar are highly conserved across species and that planarians offer an invertebrate model to provide insight into the pharmacological effects of sucrose and related sweeteners.

Systematic review: effective management strategies for lactose intolerance.

BACKGROUND: Lactose intolerance resulting in gastrointestinal symptoms is a common health concern. Diagnosis and management of this condition remain unclear. PURPOSE: To assess the maximum tolerable dose of lactose and interventions for reducing symptoms of lactose intolerance among persons with lactose intolerance and malabsorption. DATA SOURCES: Multiple electronic databases, including MEDLINE and the Cochrane Library, for trials published in English from 1967 through November 2009. STUDY SELECTION: Randomized, controlled trials of individuals with lactose intolerance or malabsorption. DATA EXTRACTION: Three investigators independently reviewed articles, extracted data, and assessed study quality. DATA SYNTHESIS: 36 unique randomized studies (26 on lactase- or lactose-hydrolyzed milk supplements, lactose-reduced milk, or tolerable doses of lactose; 7 on probiotics; 2 on incremental lactose administration for colonic adaptation; and 1 on another agent) met inclusion criteria. Moderate-quality evidence indicated that 12 to 15 g of lactose (approximately 1 cup of milk) is well tolerated by most adults. Evidence was insufficient that lactose-reduced solution or milk with a lactose content of 0 to 2 g, compared with greater than 12 g, is effective in reducing symptoms of lactose intolerance. Evidence for probiotics, colonic adaptation, and other agents was also insufficient. LIMITATIONS: Most studies evaluated persons with lactose malabsorption rather than lactose intolerance. Variation in enrollment criteria, outcome reporting, and the composition and dosing of studied agents precluded pooling of results and limited interpretation. CONCLUSION: Most individuals with presumed lactose intolerance or malabsorption can tolerate 12 to 15 g of lactose. Additional studies are needed to determine the effectiveness of lactose intolerance treatment.

The effect of oral supplementation with Lactobacillus reuteri or tilactase in lactose intolerant patients: randomized trial.

BACKGROUND: Lactase enzyme supplements and probiotics with high beta-galactosidase activity may be valid treatment options for the lactose intolerance. Aim of this study was to assess whether supplementation with tilactase or Lactobacillus reuteri when compared to placebo affects hydrogen breath excretion and gastrointestinal symptoms in lactose intolerant patients during lactose breath test (H,-LBT). METHODS: Sixty lactose intolerant patients participated in the study and were randomized to three 20 patients-treatment groups: tilactase group (tilactase 15 minutes before control H2-LBT); placebo group (placebo 15 minutes before control H2-LBT); Lactobacillus reuteri group (LR) (LR b.i.d. during 10 days before control H2-LBT). The outcomes were LBT normalization rate, and influences of treatments on both mean maximum hydrogen concentration and clinical score. RESULTS: LBT normalization rate was significantly higher in tilactase and LR groups with respect to placebo. Tilactase was significantly more effective than LR in achieving LBT normalization (p <0.01). Both significant reduction of mean peak H2 excretion and improvement of the mean clinical score were observed in tilactase and LR groups after treatment with respect to placebo (p <0.0001). Tilactase was significantly more effective than LR in reducing both mean peak hydrogen excretion and mean clinical score. CONCLUSIONS: In lactose intolerants, tilactase strongly improves both LBT results and gastrointestinal symptoms after lactose ingestion with respect to placebo. Lactobacillus reuteri also is effective but lesser than tilactase. This probiotic may represent an interesting treatment option for lactose intolerance since its use is simple and its effect may last in the time after stopping administration.

Intestinal lactase as an autologous beta-galactosidase reporter gene for in vivo gene expression studies.

Intestinal lactase has potential as an autologous beta-galactosidase reporter gene for long-term gene expression studies in vivo, using chromogenic, luminescent, and fluorogenic substrates developed for Escherichia coli beta-galactosidase. In normal rat tissues, reactivity with a chromogenic fucopyranoside (X-Fuc, the preferred substrate of lactase) was present only at the lumenal surface of small intestine epithelial cells. Full-length lactase (domains I-IV), mature lactase (domains III and IV), and a cytosolic form of mature lactase (domains III and IV, without the signal sequence or transmembrane region) were evaluated. Transfection of HuH-7 cells in vitro, and hydrodynamic gene delivery to the liver in vivo, resulted in excellent gene expression. The full-length and mature (homodimeric, membrane-bound) forms reacted strongly with X-Fuc but not with the corresponding galactopyranoside (X-Gal). However, the presumptively monomeric cytosolic lactase unexpectedly reacted equally well with both substrates. The fluorogenic substrate fluorescein-di-beta-D-galactopyranoside was cleaved by cytosolic lactase, but not by full-length or mature lactase. Full-length lactase, when expressed ectopically in hepatocytes in vivo, localized exclusively to the bile canalicular membrane. Intestinal lactase is highly homologous in mice, rats, and humans and has considerable potential for evaluating long-term gene expression in experimental animals and the clinic.