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Effects of yogurt and fermented-then-pasteurized milk on lactose absorption in an institutionalized elderly group.

In the present study we evaluated lactose malabsorption (LM) after ingestion of three dairy products in 53 healthy institutionalized elderly people. A preliminary screening with milk (250 ml, 11 g lactose) was carried out to select the LM subjects using the H2 breath test. The effect of consuming an equivalent amount of lactose contained in yogurt and fermented-then-pasteurized milk (FPM) was then assessed in LM subjects. Results indicated that 36% of the elderly population studied was considered as LM and that breath H2 excretion was significantly higher after ingestion of milk than after ingestion of yogurt. This beneficial effect was partially eliminated when FPM was tested. Moreover, breath H2 excretion was significantly higher (p less than 0.05) 3 hours after ingestion of FPM compared to the normal yogurt. These results demonstrate a high prevalence of LM in the elderly and confirm the positive effect of yogurt on lactose absorption, whereas pasteurized yogurt did not cause the same effect.

Aged↗

[Effect of surface modification on surface energy of lactose and performance of dry powder inhalations].

AIM: To investigate the effects of surface modification of lactose carrier on performance of dry powder inhalations (DPIs). METHODS: Modified lactose surface was prepared using a "particle smoothing" process to obtain smooth carrier surface and low surface energy with the presence of magnesium stearate, colloidal silica dioxide and talc. Inverse gas chromatography (IGC) was used to assess the surface energy of treated lactose, and the in vitro deposition of carrier-based IFNa-2b DPIs was evaluated with twin stage impinger. RESULTS: The flowing property of lactose was greatly improved and the surface energy decreased by the "particle smoothing" process. Decreasing surface energy resulted in greater aspiration fraction of IFNa-2b. CONCLUSION: IGC is a potentially useful tool for rapid formulation design and screening.

Administration, Inhalation↗

[The influences of lactose as an inducer on expression of plant des-pGlu1-brazzein in Escherichia coli].

Expression strain of des-pGlu1-brazzein was constructed and the conditions using lactose as inducer was also optimized. The Influences of three factors which were lactose concentration, induction time and inducing temperature on the growth of strain and on the yield of des-pGlul-Brazzein was analyzed in detail. The result indicated that high lactose concentration inhibit the growth of strains (P < 0.01) but made no difference on expression of target protein between 0.5%-5% (P > 0.05), Biomass would be improved as time passed (P < 0.01), but the yield of target protein didn't increase obviously at 30 degrees C compared with at 37 degrees C. Further result showed that the greater expressed level of des-pGlul-Brazzein, as high as about 20% of total cell protein, could be achieved after the strain had been induced with 0.5% lactose under 28 degrees C - 30 degrees C for 4 h.

Dose-Response Relationship, Drug↗

Prepartal lactose concentration in the mammary glands of Uje: WIST rats as a simple indicator of approaching parturition.

Immediately after delivery, lactose was reliably detectable in rat mammary glands (mean concentration 6.49 +/- 0.57 mg/g tissue). The concentrations were not influenced by prepartal biopsy of contralateral mammary tissue. In the morning of the 21st day of gestation (= expected day of labor), lactose was evident in the mammary glands of dams delivering at that day (mean concentration 2.39 +/- 0.17 mg/g tissue). In the tissue of dams delivering on day 22 of gestation, lactose was undetectable. A correlation between prepartal lactose concentration of mammary gland and time remaining up to beginning of delivery (r = -0.96) qualifies this parameter as a rough indicator of term of parturition.

Animals↗

Effect of anaerobic cecal microflora and dietary lactose on colonization resistance of layer chicks to invasive Salmonella enteritidis.

The effect of oral inoculation with anaerobic cultures of cecal microflora and providing lactose in the feed on colonization resistance to invasive Salmonella enteritidis was evaluated in newly hatched leghorn chicks. Salmonella colonization of the ceca, tissue invasion and organ colonization, horizontal transmission, and seroconversion were significantly decreased (P less than 0.01) in chicks inoculated with cecal flora. The addition of lactose to the feed, in the absence of cecal microflora, failed to provide protection. Dietary lactose enhanced colonization resistance in chicks that were inoculated with anaerobic cultures of cecal flora. The results indicated that establishment of normal cecal flora in layer chicks together with the addition of lactose to the diet markedly increases resistance to cecal colonization and organ invasion, and decreases horizontal transmission of S. enteritidis.

Animal Feed↗

Acute effects of abdominopelvic irradiation on the orocecal transit time: its relation to clinical symptoms, and bile salt and lactose malabsorption.

Twenty-five patients with abdominopelvic malignant tumors receiving irradiation were studied. The following items were assessed before, during, and at the end of the radiation period: 1) clinical symptoms, scored on the basis of their severity; 2) orocecal transit time (lactulose-H2 breath test); and 3) absorption of lactose and bile salts. Ninety-two percent of the patients showed clinical symptoms suggestive of acute radiation enteropathy, mainly diarrhea. A significant acceleration of the orocecal transit was observed during the study: 70 +/- 6.9 min vs 63.3 +/- 6.3 min vs 44.3 +/- 5.1 min (F = 5.49, p = 0.008), being faster in patients with severe diarrhea (F = 3.25, p = 0.05). Forty-four percent and 57% of the patients developed lactose and bile salt malabsorption, respectively. A decrease in the transit time was observed, independent of the absorption or malabsorption of such substances. However, the orocecal transit was faster in those lactose malabsorbers with severe diarrhea, than in those with mild diarrhea (F = 4.2, p = 0.03). The results suggest that acceleration of orocecal transit may be a major factor in the pathophysiology of radiation-induced diarrhea, whereas lactose malabsorption may contribute to the severity of the diarrhea.

Abdominal Neoplasms↗

Role of a soy-based lactose-free formula in the outpatient management of diarrhea.

The introduction of a soy-based, lactose-free formula during the acute phase of diarrheal illness in infants has been shown to reduce stool output and duration of diarrhea in hospitalized patients. In the United States, most infants with acute diarrhea are treated as outpatients. In the present study, infants with diarrhea who were treated as outpatients were randomly assigned to receive either a soy-based, lactose-free formula alternating with oral rehydration solution from the beginning of therapy ("early feeding") or oral rehydration solution alone for the first 24 hours of therapy, followed by a soy-based, lactose-free formula alternating with oral rehydration solution (control group). Twenty-nine infants were randomly assigned to the early-feeding group and 27 to the control group. Twenty-one (72%) of 29 in the early-feeding group resolved their diarrhea at the end of 48 hours of therapy compared with 12 (44%) of 27 in the group fed oral rehydration solution only (P = .02). It is concluded that the introduction of a soy-based, lactose-free formula from the beginning of therapy for acute diarrhea in children treated as outpatients is safe and may shorten duration of diarrhea while maintaining adequate caloric intake.

Ambulatory Care↗

[Intestinal parasites and lactose malabsorption].

Breath-test was performed for diagnosis of lactose malabsorption in 50 Gabonese children of normal nutritional status, aged 5 to 15 years, with parasites in stools, but without diarrhoea or digestive symptoms. Control group was unparasitized and consisted of 17 children and 18 young adults living in the same area. Parasites discovered by stool examination were Ascaris lumbricoides in 76% of parasitized children, Trichuris trichiura in 58%, Giardia in 24%, Entamoeba histolytica in 20%, Schistosoma intercalatum in 16% and Necator Americanus in 14%. Children were given a 10 g lactose load and adults 20 g. Lactose malabsorption was discovered in 64% of parasitized patients and in 63% of unparasitized. Ten of 12 (83.3%) of Giardia infected children had a lactose malabsorption (no significant difference). These data show that decrease of lactase activity in African children is not related to the presence or to the importance of intestinal parasitism, except for Giardia infestation, if nutritional status is normal.

Adolescent↗

Characterization of the lactose-specific enzymes of the phosphotransferase system in Lactococcus lactis.

The plasmid-encoded lactose genes of the Lactococcus lactis phosphotransferase system encoding Enzyme IIIlac (lacF) and Enzyme IIlac (lacE) have been identified and cloned in Escherichia coli and L. lactis. Nucleotide sequence and transcription analysis showed that these genes are organized into a lactose-inducible operon with the gene order lacF-lacE-lacG-lacX, the latter two genes encoding phospho-beta-galactosidase and a 34-kDa protein with an unknown function, respectively. The lac-operon is immediately followed by an IS element that is homologous to ISS1. Enzyme IIIlac was purified from L. lactis and determination of its NH2-terminal sequence demonstrated that the lacF gene starts with a TTG codon and encodes a 105 amino acid protein (Mr = 11416). Cross-linking studies with the purified enzyme showed that Enzyme IIIlac is active as a trimer. A mutant lacF gene was identified in strain YP2-5 and appeared to encode Enzyme IIIlac containing the missense mutation G18E. The lacF gene could be expressed under control of vector-located promoter sequences resulting in overproduction of Enzyme IIIlac in E. coli and complementation of the L. lactis lacF mutant YP2-5. The deduced amino acid sequence of Enzyme IIlac consists of 586 amino acids (Mr = 61562) and shows the characteristics of a hydrophobic, integral membrane protein. The deduced primary structures of the L. lactis Enzyme IIIlac and Enzyme IIlac are homologous to those of Staphylococcus aureus (72 and 71% identity, respectively) and Lactobacillus casei (48 and 47% identity, respectively). In contrast, the organization of the lactose genes differs significantly between those Gram-positive bacteria. Heterogramic homology in specific domains was observed between the derived amino acid sequences of the lactose-specific enzymes and that of E. coli Enzyme IIIcel and Enzyme IIcel, which suggest a common function in the transport and phosphorylation of these structurally related beta-glucosides.

Amino Acid Sequence↗

Lactose maldigestion--age-specific prevalence in black and Indian children.

A study was performed to determine the prevalence and age of onset of primary lactose maldigestion in healthy black and Indian children, and to determine whether this was of clinical significance. More black (22 of 44-50%) than Indian children (10 of 45-22.2%) had lactose maldigestion (P less than 0.02), the development of which was age-related and occurred earlier in blacks than in Indians; 6 of 19 black children less than 5 years old (31.6%) were lactose maldigesters, compared with 8 of 10 (80%) over 10 years old, while only 1 of 16 Indian children aged under 8 years (6.3%) were maldigesters, compared with 5 of 13 (38.5%) aged over 10 years. Most children had a very low intake of milk and lactose maldigestion was of no clinical significance to them.

Age Factors↗

Characterization of the binding of propionibacterium granulosum to glycosphingolipids adsorbed on surfaces. An apparent recognition of lactose which is dependent on the ceramide structure.

The binding properties of a strain of Propionibacterium granulosum derived from human skin was investigated with reference to glycosphingolipids separated on thin layer chromatograms or coated in microtiter wells using externally (125I) and metabolically [( 35S]methionine) labeled bacteria. Binding was found to lactosylceramide (LacCer; Gal beta 1-4Glc beta 1-Cer) but not to glycolipids lacking the lactose sequence (i.e. Glc beta 1-Cer, Gal beta 1-Cer or Gal alpha 1-4Gal beta 1-Cer). In microtiter wells, binding occurred at 50 ng and became half-maximal at the theoretical value for a monomolecular layer of LacCer (i.e. 100-200 ng/well). The bacteria also bound to glycolipids with various substitutions (e.g. GalNAc beta 1-4, Gal beta 1-3GalNAc beta 1-4, Fuc alpha 1-2Gal beta 1-3GalNAc beta 1-4, Gal alpha 1-3, GlcNAc beta 1-3, Gal beta 1-3GlcNAc beta 1-3, Gal beta 1-4GlcNAc beta 1-3, and Gal beta 1-3(Fuc alpha 1-4)GlcNAc beta 1-3) at the Gal of LacCer, although only those species with GalNAc beta 1-4 or Gal beta 1-3GalNAc beta 1-4 were as active as LacCer itself. Glycolipids with other additions (e.g. Gal alpha 1-4 and NeuAc alpha 2-3) were negative. For unsubstituted LacCer, the binding required either a trihydroxy base or 2-hydroxy fatty acid, specifying the epithelial type of ceramide; LacCer composed of a dihydroxy base and nonhydroxy fatty acid was negative. This is interpreted as indicating that the proper presentation of the binding epitope depends on the ceramide structure. The relevance of this to biological membranes has not yet been established. Neither free lactose (up to 20 mg/ml) nor lactose-bovine serum albumin (5 mg/ml) prevented the binding of bacteria to LacCer, two facts that support the solid-phase binding data demonstrating a low affinity binding and the crucial importance of a particular lactose epitope.

Adsorption↗

Recent advances in the management of lactose intolerance.

Lactose intolerance is a concern for the majority of the world's population. Persons who experience symptoms following the consumption of milk should consult with their physician. Symptoms may be eliminated or reduced with good dietary management that includes: 1. limiting milk consumption to one glass at a time; 2. drinking milk with other foods rather than alone; 3. eating yogurts instead of fluid milk; 4. using enzyme tablets to predigest the lactose in milk or to supplement the body's own lactase; 5. possibly eating small amounts of dairy foods each day to adapt the colonic bacteria. For an additional review of the research findings on lactose intolerance and milk drinking, the reader is directed to reference 4, a very recent and complete review by Scrimshaw and Murray. For information on dietary management of lactose intolerance suitable for the consumer, contact your local affiliate of the National Dairy Council.

Calcium↗

Sugar transport by the bacterial phosphotransferase system. In vivo regulation of lactose transport in Escherichia coli by IIIGlc, a protein of the phosphoenolpyruvate:glycose phosphotransferase system.

Escherichia coli and Salmonella typhimurium preferentially utilize sugar substrates of the phosphoenol-pyruvate:glycose phosphotransferase system (PTS) when the growth medium also contains other sugars. This phenomenon, diauxic growth, is regulated by the crr gene, which encodes the PTS protein IIIGlc (Saffen, D.W., Presper, K.A., Doering, T.L., and Roseman, S. (1987) J. Biol. Chem. 16241-16253). We have proposed that non-PTS permeases are regulated by their interaction with IIIGlc, and in vitro studies from other laboratories have provided support for this model, but the in vivo effects of excess IIIGlc are not known. In the present studies, transformed cells that overproduced IIIGlc 2- and 10-fold, respectively, were constructed from a pts+ strain of E. coli and plasmids containing the crr gene. In the 2-fold overproducer, fermentation of, and growth on the non-PTS carbohydrates glycerol, lactose, maltose, and melibiose was generally more sensitive to the glucose analogue methyl-alpha-D-glucopyranoside than in a control strain containing normal levels of IIIGlc. In addition, inhibition of lactose permease activity by methyl-alpha-glucoside (inducer exclusion) was more effective in the 2-fold overproducer than in the control strain, particularly when the permease activity was high. The 10-fold IIIGlc overproducing strain had a requirement for the amino acids methionine, isoleucine, leucine, and valine that may or may not be related to the increased concentration of IIIGlc. Fermentation of non-PTS carbohydrates was also poor in the latter strain. Finally, lactose permease activity was 50% of that in control cells containing the same levels of beta-galactosidase, and the lactose permease activity in the IIIGlc overproducer was reduced to an extremely low level in the presence of methyl alpha-glucoside. Thus there is an inverse relationship between the cellular concentration of IIIGlc and the ability to metabolize non-PTS substrates. The results are consistent with the model where inducer exclusion is affected by a direct interaction between IIIGlc and a non-PTS transport system.

Carbohydrate Metabolism↗

Simultaneous determination of dextrose, sucrose, maltose, and lactose in sausage products by liquid chromatography.

A liquid chromatographic (LC) method for the simultaneous determination of dextrose, sucrose, maltose, and lactose in sausage products has been developed. Dextrose, sucrose, maltose, and lactose are extracted from comminuted meat products with 52% ethanol. After filtration, the extracts are purified by passing them through a C18 Sep-Pak cartridge and 2 ion exchange resin Econo-columns in series. After concentration and filtration, extracts are analyzed by LC using a normal phase amino column and a differential refractometer detector. Homogeneously ground samples of cooked and fresh sausages are fortified with dextrose, sucrose, maltose, and lactose at 4 different concentrations. Average recovery for dextrose, sucrose, maltose, and lactose at all 4 levels of fortification was greater than 80% with a coefficient of variation less than 10%.

Carbohydrates↗

Glucose and insulin responses to meals containing milk, lactose, glucose or fructose in subjects with non-insulin-dependent diabetes.

The postprandial blood glucose and serum insulin responses to liquid test meals containing 40 g carbohydrate from milk, lactose, glucose or fructose and equal amounts of energy were compared in 10 non-insulin-dependent (type 2) diabetic patients. The meals were consumed in random order on consecutive days after an overnight fast. Significant differences (p less than 0.001, ANOVA) were observed between the glucose and insulin responses to the meals. The glucose response was significantly higher after the glucose containing meal and lower after the fructose meal as compared with the other meals. The insulin response was significantly higher after the lactose and glucose meals than after the milk and fructose meals. After the milk and lactose meals the blood glucose responses were similar whereas the insulin response was significantly lower after the milk meal. As lactose apparently was similarly absorbed from the two meals the difference in the insulin response was probably due to different insulinogenic effects of the protein components or to differences in the physical properties of the respective meals.

Adult↗

[Experimental dilatation of the cecum and colon in rats. II. Reversion after induction by the continuous administration of lactose].

Fifty female Wistar weanling rats were fed a laboratory diet containing lactose (25 g/100 g of the final mixture) during 28 days. Following this period the lactose was substituted isocalorically by saccharose (25 g/100 g of the final mixture) and the diet given to the animals for 21 days. Thirty control rats of the same sex and weight received a laboratory diet containing saccharose (25 g/100 g of diet) during 49 days. The animals were weighed weekly. Subgroups of experimental and control rats were sacrificed at days 28, 30, 32, 35, 42 and 49. Rats given a diet containing lactose showed restriction of body weight gain. Upon rehabilitation the body weight of these animals increased rapidly. The external volume of the cecum and colon showed a significant increase during the 28-day period. After nutritional rehabilitation this change reduced gradually, beginning in the first week. Although the weight of the cecum reduced gradually during the rehabilitation period, the values were slightly augmented at day 49 as compared to controls. In conclusion, in the conditions of the present study, the consequences on the cecum and colon of adding lactose to the diet of rats are not persistent.

Animals↗

Recurrent abdominal pain in children: lactose and sucrose intolerance, a prospective study.

Thirty-eight consecutive children with recurrent abdominal pain underwent lactose tolerance tests; 28 of these were also given sucrose tolerance tests. Abdominal pain and abnormal lactose tolerance tests were noted in 11 of 38, while none of the 28 had an abnormal sucrose tolerance test; however, 1 had abdominal pain. Elimination diet for 4 weeks produced significant or total pain relief in 10 of 11 (lactose free) and 0 of 1 children (sucrose free). Lactose intolerance seems to play a contributory role in recurrent abdominal pain in children, while sucrose intolerance does not.

Abdomen↗

Utilization of lactose and production of corrinoids in selected strains of propionic acid bacteria in cheese-whey and casein media.

Comparative studies were carried out with 23 strains (14 species) of propionibacteria in two media-cheese-whey and casein. The degree of lactose fementation and the efficiency of the corrinoids synthesis were studied. Lactose fermentation showed great differences even within one species (e.g. 13.3% and 66.1% for various strains of P. shermanii). The differences were particularly sharp in casein medium (0% or 100%). The highest capacity for utilizing cheese-whey lactose (70--80%) was found in two strains of P. shermanii and P. petersonii and P. arabinosum. No definite correlation, however, was found either in the cheese-whey or in the casein medium, between the capability of lactose fermentation and the efficiency of the corrinoids. As the most technologically effective strains have been recognized P. shermanii 1, P. shermanii 566 and P. petersonii J.

Caseins↗