Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Rotaviruses are now regarded as important causes of diarrhoea in man, cattle, pigs, mice, and possibly other animals. Characteristically, disease occurs in newborn and young animals, and infection seems limited to the differentiated gut epithelial cells. The major surface polypeptide of the calf scours rotavirus is glycosylated, and highly purified beta-galactosidase (lactase) interacts with the virus in vitro causing removal of the outer shell of the capsid (uncoating). It is suggested that lactase present in the brush border of the intestinal epithelial cell performs a similar function in vivo by acting as a combined receptor and uncoating enzyme for the rotavirus. This hypothesis is consistent with the observations that rotaviruses seem to infect only gut epithelial cells, and that infant animals, whose lactase concentrations are generally higher than those of adult animals, seem more susceptible to rotavirus infections. Implications of the hypothesis include possible new approaches to laboratory cultivation of rotaviruses, which should be more successful in cells selected for surface lactase activity, and the suggestion that the epidemiology of human rotavirus infections may be influenced by the fact that different ethnic groups have different lactase levels (and hence lactose intolerance) in adulthood.
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PMID:Is lactase the receptor and uncoating enzyme for infantile enteritis (rota) viruses? 5 21

The clinical efficacy and the potential side-effects of beta-galactosidase were studied in adult lactose intolerance. Various randomized oral tolerance tests were performed using lactose solution (35 g), glucose + galactose solution (17.5 + 17.5 g), native, skimmed milk and milk pretreated with beta-galactosidase. In each case, simultaneous examinations were made of the glucose concentration of capillary blood by an instrument constructed by the authors, of the H2 content of expired air as also of the subjective complaints and of the number of stools and their pH. It was established that pretreatment of milk with beta-galactosidase has a beneficial effect in adult lactose maldigestion, since it stops dyspeptic complaints and diarrhoea due to milk, it reduces the H2 content of expired air increases blood glucose concentration. Measuring the H2 content of the breath by using and instrument constructed by the authors, exact data can be obtained noninvasively, and rapidly on the degree of carbohydrate malabsorption in patients with lactose-intolerance.
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PMID:Efficacy testing of beta-galactosidase with H2 breath test in patients with carbohydrate malabsorption. 311 27

We conducted blinded, controlled crossover studies to determine the effect of daily lactose feeding on colonic adaptation and intolerance symptoms. The initial study with nine lactose maldigesters showed a threefold increase in fecal beta-galactosidase activity after 16 d of lactose feeding. To determine the effects of this adaptation on breath hydrogen and intolerance symptoms, 20 lactose-maldigesting adults were randomly assigned to lactose or dextrose supplementation for 10 d (days 1-10), crossing over to the other period for days 12-21. The sugar dosage was increased from 0.6 to 1.0 g.kg-1.d-1, subdivided into three equal doses, by adjusting the dose every other day. Symptoms during lactose supplementation and comparison of symptoms during the lactose and dextrose feeding periods showed no significant differences. On days 11 and 22, challenge doses of lactose (0.35 g/kg) were administered after an overnight fast, and breath hydrogen and intolerance symptoms (abdominal pain, flatulence, and diarrhea) were carefully monitored for 8 h. Frequency of flatus passage and flatus severity ratings after the lactose challenge decreased 50% when studied at the end of the lactose period compared with the dextrose period. The sum of hourly breath-hydrogen concentrations (1-8 h) was significantly reduced after the lactose feeding period (9 +/- 38 ppm.h) compared with after the dextrose period (385 +/- 52 ppm.h, P < 0.001). We conclude that there is colonic adaptation to regular lactose ingestion and this adaptation reduces lactose intolerance symptoms.
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PMID:Colonic adaptation to daily lactose feeding in lactose maldigesters reduces lactose intolerance. 869 25

Fifteen lactose malabsorbers were studied to evaluate the effects of consumption of milk containing different strains of Bifidobacterium longum on lactose digestion. Influences of different growth substrates, bile sensitivity, and lactose transport on lactose digestion by bifidobacteria were also investigated. Lactose malabsorption was determined by measuring breath hydrogen excretion of subjects fed four different test milks (three of which contained 5 x 10(8) cfu/ml of B. longum) on 4 different d using a randomized, double-blinded trial. Test milks included 1) 400 ml of lowfat milk (control), 2) 400 ml of milk containing B. longum B6 that had been grown with lactose, 3) 400 ml of milk containing B. longum B6 grown with lactose plus glucose, or 4) 400 ml of milk containing B. longum ATCC 15708 grown with lactose. beta-Galactosidase activity was highest in milk containing B6 grown with lactose but was extremely low in milk containing B6 grown with lactose and glucose. Consumption of milk containing B6 grown with lactose resulted in significantly less hydrogen production and flatulence than occurring after consumption of control milk or the milk containing B6 grown with both lactose and glucose. Hydrogen production after ingestion of 15708 was also significantly lower than hydrogen production after ingestion of the control milk. We concluded that milks containing B. longum might reduce breath hydrogen response and symptoms from lactose malabsorption when the culture is grown in a medium containing only lactose to induce a higher beta-galactosidase level and increase rate of lactose uptake.
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PMID:Improvement of lactose digestion in humans by ingestion of unfermented milk containing Bifidobacterium longum. 879 77

Microorganisms in yogurt have the capacity of quantitatively digest in vivo in the small intestine the lactose from yogurt. The process of autodigestion of lactose in yogurt reduces both lactose maldigestion and lactose intolerance in lactase deficient individuals. Enzyme activity in yogurt depends upon the buffer capacity of the yogurt, microbial cells resistance to acid and enzymatic activity and to the effect of bile in the microbial cell that release beta-galactosidase activity. Lactose autodigestion capacity of yogurt is significantly reduced in pasteurized yogurt and it is also affected by the type and amount of microorganism that is added to milk and by the presence of fat. Yogurt intake represents an important food alternative for lactase deficient individuals.
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PMID:[Yogurt as source of lactose autodigestion]. 912 49

The influence of bile sensitivity, lactose transport, and acid tolerance of Lactobacillus acidophilus on in vivo digestion of lactose was investigated. Four strains of L. acidophilus exhibiting varied degrees of lactose transport, beta-galactosidase activity, and bile sensitivity were used to prepare unfermented acidophilus milks. Lactose malabsorption was evaluated by measuring breath H2 excretion off 11 lactose maldigesting subjects following ingestion of four acidophilus test milks. Test meals were fed in a randomized double-blind protocol. Consumption of acidophilus milk (2% fat) containing strains B, N1, and E significantly reduced mean total H2 production compared with that of the control reduced-fat (2% fat) milk, but milk containing strain ATCC 4356 did not differ from the control. Acidophilus milk containing L. acidophilus N1 was the most effective of the four acidophilus milks in improving lactose digestion and tolerance. Strain N1 exhibited the lowest beta-galactosidase activity and lactose transport but the greatest bile and acid tolerance of the four strains. The results indicated that bile and acid tolerance may be important factors to consider when L. acidophilus strains are selected for improving lactose digestion and tolerance.
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PMID:Improvement of lactose digestion by humans following ingestion of unfermented acidophilus milk: influence of bile sensitivity, lactose transport, and acid tolerance of Lactobacillus acidophilus. 927 91

Colonic fermentation plays an important role in the prevention of lactose intolerance and intestinal disorders. The objectives of this study were to evaluate whether supplementation with bifidobacteria modify colonic fermentation of lactose and short-chain fatty acid production and to assess influence of the pH in an in vitro continuous culture system. There was a significantly greater reduction in lactose concentrations at pH 6.7 than that at either pH 6.2 or pH 5.7, accompanied by the highest beta-galactosidase activity and D-lactate production. Bifidus supplementation reduced lactose and D-lactate concentrations and increased acetate production at pH 6.7. The study demonstrates that lactose is rapidly metabolized by colonic bacteria and lactose fermentation in vitro is pH dependent with a maximum rate at pH 6.7. Bifidobacteria supplementation may have the potential to improve lactose fermentation and to manipulate SCFA and lactate production.
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PMID:Modification of colonic fermentation by bifidobacteria and pH in vitro. Impact on lactose metabolism, short-chain fatty acid, and lactate production. 939 19

The disaccharide lactose is present as a natural component of foods only in milk and dairy products. In the gastrointestinal tract, lactose is hydrolysed by the enzyme beta-galactosidase (lactase) into glucose and galactose. These components are absorbed. With the exception of the caucasian race, the lactase activity decreases in most people at an age of 4 to 6 years. Lactose intake can cause symptoms of bloating, flatulence, abdominal pain, and diarrhea due to the lactose reaching the large intestine. This phenomenon is called lactose intolerance. It is generally recommended to those persons that they refrain from the consumption of milk and dairy products. However, most lactose intolerant people are able to digest small amounts of milk. They can also consume cheese that contains no (hard and semi-hard) or only small amounts of lactose (present in only 10% of soft cheeses). These products are very important sources of calcium. Compared to milk, the lactose content of yogurt is usually lower by about one third. Studies during the last 10 years have shown that in spite of its lactose content yogurt is very well tolerated by lactose intolerant persons. This advantage is ascribed to the presence of living lactic acid bacteria in fermented dairy products which survive passage through the stomach and also to the lactase present in these products.
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PMID:[Lactose intolerance and consumption of milk and milk products]. 946 38

The effectiveness of a new beta-D-galactosidase pellet formulation in the treatment of lactose intolerance was studied. The encapsuled beta-D-galactosidase (lactase) pellets were first tested in vitro for their enzymatic activity within an environment simulating gastric conditions and subsequently within an environment simulating duodenal conditions. Effectiveness was measured by the % of glucose formed by hydrolysis of lactose. The pellets were found to retain their enzymatic activity in gastric pH conditions (mean 69 +/- 1 mg/dl glucose) and were found to hydrolyse lactose in human duodenal fluid (106.35 +/- 1 mg/dl). Finally the effectiveness of the new lactase formulation on glucose absorption was studied in 8 lactose intolerant subjects in a randomized, double blind, crossover trial. After fasting, the subjects were given one capsule containing 100 u/ml beta-galactosidase (i.e. 10 pellets of 10 u/ml each) or one capsule containing placebo pellets, followed by 100 g lactose dissolved in water. The washout period between lactose challenges was one week. Plasma glucose concentrations were measured before and at intervals after the challenges and the subjects completed symptom questionnaires every eight hours for 24 hours. Results showed a statistically significant increase in plasma glucose levels 30, 60, 90 and 120 min after lactose ingestion (repeated measures analysis of variance, p<0.01). Subjective ratings of the severity of abdominal cramping, belching, flatulence, vomiting and diarrhoea were significantly decreased following ingestion of the lactase pellets and lactose (no incidence of diarrhoea) compared with after ingestion of placebo and lactose. The results of the study were considered to be very promising as the beta-D-galactosidase formulation (which was produced at very low cost and with great ease) resisted inactivation in the stomach, effectively transformed lactose to glucose in vivo and reduced symptoms of lactose intolerance.
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PMID:Treatment of lactose intolerance with exogenous beta-D-galactosidase in pellet form. 972 5

Gene therapy is usually reserved for severe and medically refractory disorders because of the toxicity, potential long-term risks and invasiveness of most gene transfer protocols. Here we show that an orally administered adeno-associated viral vector leads to persistent expression of a beta-galactosidase transgene in both gut epithelial and lamina propria cells, and that this approach results in long-term phenotypic recovery in an animal model of lactose intolerance. A gene 'pill' associated with highly efficient and stable gene expression might be a practical and cost-effective strategy for even relatively mild disorders, such as lactase deficiency.
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PMID:Peroral gene therapy of lactose intolerance using an adeno-associated virus vector. 977 39


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