Leche materna deslactosada con la enzima beta galactosidasa para lactantes intolerantes / Leite materno sem lactose com a enzima beta-galactosidase para lactentes intolerantes / Lactose-free breast milk with the enzyme beta galactosidase for intolerant infants

Introducción: los bebés deben beneficiarse de la leche materna, incluso cuando presentan intolerancia a la lactosa. Por esto, se debe recurrir a la obtención de leche materna deslactosada. Objetivo: analizar el efecto de la enzima beta galactosidasa en la hidrólisis de la lactosa de leche materna madura para bebés clínicamente diagnosticados con intolerancia a la lactosa. Materiales y método: estudio exploratorio, descriptivo y explicativo. El contenido de lactosa se cuantificó desde el inicio hasta el final del tratamiento, controlando temperatura, tiempos y cantidad de enzima ß-galactosidasa adicionada en la leche materna. Se recolectaron 1000 ml de leche materna, obtenidos del Banco de Leche del Hospital General de Medellín (Antioquia, Colombia). Resultados: las muestras donadas se encontraban pasteurizadas y posteriormente fueron sometidas a la acción de la enzima lactasa. Se cuantificó el contenido de lactosa sin la enzima, reportando en promedio 6,34 mg/100 ml ± 0,23. El mayor aporte de lactosa obtenido posterior a la exposición a la enzima (30 minutos) fue de 6,07 mg/ml ± 0,35 (correspondiente a 95 % del contenido inicial), finalizando con un aporte de 0,35 % a una concentración de 0,4 % tras 24 horas, porcentaje que representa 95 % de la hidrólisis total en la leche materna. Conclusiones: en todas las muestras analizadas de diferentes madres se pudo obtener leche materna con bajas concentraciones de lactosa tras 24 horas de haber sido sometidas a la acción de ß-galactosidasa. Lo anterior se establece como una alternativa para los bebés intolerantes a la lactosa, que permitiría no privarlos de todos los beneficios que ofrece este alimento.

Introduction: Babies should benefit from breast milk, even when they are lactose intolerant. For this reason, parents should resort to obtaining lactose-free breast milk. Objective: To examine the effect of the enzyme ß-galactosidase on the hydrolysis of lactose in mature breast milk for babies clinically diagnosed with lactose intolerance. Materials and method: Exploratory, descriptive, and explanatory study. The lactose content was quantified from the beginning to the end of the treatment, controlling variables such as temperature, times, and the amount of ß-galactosidase enzyme added in breast milk. A total of 1000 ml of breast milk were obtained from the milk bank at Hospital General de Medellín (Antioquia, Colombia). Results: Donated samples were first pasteurized and subsequently subjected to the action of the enzyme lactase. The lactose content without the enzyme was quantified, reporting an average of 6.34 mg/100 mL±0.23. The highest contribution of lactose obtained after exposure to the enzyme was 6.07 mg/mL±0.35 (corresponding to 95% of the initial content), at 30 minutes, ending with a contribution of 0.35% at a concentration of 0.4% in 24 hours, percentage that represents 95% of total hydrolysis in breast milk. Conclusions: In all the examined samples from different mothers, it was possible to obtain breast milk with low concentrations of lactose 24 hours after these were exposed to the action of ß-galactosidase. This becomes an alternative for feeding lactose intolerant babies and not deprive them from all the benefits offered by breast milk.

Introdução: os bebês se devem beneficiar do leite materno, mesmo quando tenham intolerância à lactose, razão pela qual se deve recorrer à obtenção de leite materno sem lactose. Objetivo: analisar o efeito da enzima beta-galactosidase na hidrólise da lactose no leite materno maduro para bebês diagnosticados clinicamente com intolerância à lactose. Materiais e método: estudo exploratório, descritivo, explicativo. O teor de lactose foi quantificado do início ao fim do tratamento; temperatura, tempos e quantidade de enzima beta-galactosidase adicionada no leite materno foram controlados; foram coletados 1000ml de leite materno, obtidos no Banco de Leite do Hospital General de Medellín (Antioquia, Colômbia). VResultados: as amostras doadas foram pasteurizadas e posteriormente submetidas à ação da enzima lactase. O teor de lactose sem a enzima foi quantificado, relatando uma média de 6,34mg/100ml±0,23. A maior contribuição de lactose obtida após a exposição à enzima foi de 6,07mg/ml±0,35 (correspondendo a 95% do conteúdo inicial) em 30 minutos, finalizando com uma contribuição de 0,35% na concentração de 0,4% em 24 horas, percentual que representa 95% da hidrólise total no leite materno. Conclusões: em todas as amostras analisadas de diferentes mães, foi possível obter leite materno com baixas concentrações de lactose 24 horas após ser submetido à ação da beta galactosidase, como alternativa para bebês intolerantes à lactose e não os privar de todos os outros benefícios oferecidos por esse alimento ideal.

Correlation between lactose absorption and the C/T-13910 and G/A-22018 mutations of the lactase-phlorizin hydrolase (LCT) gene in adult-type hypolactasia

The C/T-13910 mutation is the major factor responsible for the persistence of the lactase-phlorizin hydrolase (LCT) gene expression. Mutation G/A-22018 appears to be only in co-segregation with C/T-13910. The objective of the present study was to assess the presence of these two mutations in Brazilian individuals with and without lactose malabsorption diagnosed by the hydrogen breath test (HBT). Ten milk-tolerant and 10 milk-intolerant individuals underwent the HBT after oral ingestion of 50 g lactose (equivalent to 1 L of milk). Analyses for C/T-13910 and G/A-22018 mutations were performed using a PCR-based method. Primers were designed for this study based on the GenBank sequence. The CT/GA, CT/AA, and TT/AA genotypes (lactase persistence) were found in 10 individuals with negative HBT. The CC/GG genotype (lactase non-persistence) was found in 10 individuals, 9 of them with positive HBT results. There was a significant agreement between the presence of mutations in the LCT gene promoter and HBT results (kappa = -0.9, P < 0.001). The CT/AA genotype has not been described previously and seems to be related to lactase persistence. The present study showed a significant agreement between the occurrence of mutations G/A-22018 and C/T-13910 and lactose absorption in Brazilian subjects, suggesting that the molecular test used here could be proposed for the laboratory diagnosis of adult-type primary hypolactasia.

Lactase mRNA Expression in Small Intestines of Korean Fetuses and Adults / 대한내과학회지

OBJECTIVE: The specific activity of lactase-phlorizin hydrolase (LPH) is very high at birth and sharply declines after weaning, producing lactose intolerance. The prevalence of lactose intolerance is up to 85% in Korean adults. Molecular basis of the regulatory mechanisms responsible for the decline of LPH specific activity is still unknown. In order to elucidate the molecular mechanisms regulating the LPH expression during development, LPH specific activity and mI4NA level of Korean fetal and adult intestines were compared. METHODS: 20 fetal small intestines (16-27 weeks) were obtained during therapeutic abortion and were divided into 3 equal length. 20 adult jejunal tissues were obtained from patients without small intestinal disease during laparotomy. Mucosal homogenates were prepared for dissacharidases specific activities measurement and total RNA was extracted for northern and slot hvbridization. LPH mRNA level was measured by laser densitometer. RESULTS: LPH specific activities of proximal, middle and distal portion of fetal intestines (n=20) were 36.2 +/- 22.5, 38.6 +/- 23.2 and 23.2 +/- 19.9 mu/mg protein, respectively. LPH specific activity of adult jejunum (n=8) was 5.9 +/- 1.8 mu/mg protein and significantly (p<0.05) lower than those of fetal intestines. However, there was no significant difference in sucrase and trehalase specific activities between fetal intestines and adult jejunum. Although LPH specific activity of adult jejunum was lower than those of fetal intestines, LPH mBNA level of adult jejunum was as high as those of fetal intestines. CONCLUSION: These results show that LPH specific activity and mRNA level do not parallel, indicating the posttranscriptional control of fetal development of LPH expression.