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)

Nine healthy volunteers were studied before, during, and after ingesting a fermented dairy product containing Lactobacillus acidophilus, Bifidobacterium bifidum, and mesophilic cultures (Streptococcus lactis and S cremoris) for 3 wk. Hydrogen and methane productions and fecal beta-galactosidase and beta-glucosidase activities were measured as indicators of fermentation capacity of the colonic flora. Fecal concentrations of nitroreductase, azoreductase, and beta-glucuronidase, which may be implicated in colonic carcinogenesis, were also assessed. Hydrogen and methane productions, fecal beta-galactosidase, beta-glucuronidase, and azoreductase activities did not change over three 3-wk periods whereas fecal beta-glucosidase activity increased (42 +/- 6, 91 +/- 12, and 40 +/- 6 IU/g N, P less than 0.01) and nitroreductase decreased (0.87 +/- 0.13, 0.54 +/- 0.11, and 0.57 +/- 0.08 IU/g N, P less than 0.05).
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PMID:Effect of chronic ingestion of a fermented dairy product containing Lactobacillus acidophilus and Bifidobacterium bifidum on metabolic activities of the colonic flora in humans. 211 57

Sodium arsenite at a non-toxic concentration was found to inhibit strongly mutagenesis induced by ultraviolet light (UV), 4-nitroquinoline-1-oxide (4NQO), furylfuramide (AF-2) and methyl methane-sulfonate (MMS) as well as spontaneous mutation in the reversion assay of E. coli WP2uvrA/pKM101. The effect was not, however, seen in the case of the mutagenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). In order to elucidate the mechanism of the mutation-inhibitory effect of sodium arsenite, its action on umuC gene expression and DNA-repair systems was investigated. It was found that sodium arsenite depressed beta-galactosidase induction, corresponding to the umuC gene expression. For UV-irradiated E. coli strains possessing different DNA-repair capacities, sodium arsenite decreased the UV survival rates of WP2, WP2uvrA[uvrA] and WP67[uvrA polA], increased those of SOS-uninducible strains having either the recA+ or uvrA+ such as CM571 [recA], CM561 [lexA(Ind-)] and CM611[uvrA lexA (Ind-)], and did not affect that of the uvrA recA double mutant, WP100. From these results, we assume that sodium arsenite may have at least two roles in its antimutagenesis: as an inhibitor of umuC gene expression, and as an enhancer of the error-free repairs depending on the uvrA and recA genes.
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PMID:Sodium arsenite inhibits spontaneous and induced mutations in Escherichia coli. 330 58

Using germ-free rats inoculated with a human faecal flora (gnotobiotic rats), the effects of three oligosaccharides (beta-fructo-oligosaccharides (FOS), beta-galacto-oligosaccharides (TOS) and alpha-gluco-oligosaccharides (GOS)) on intestinal bacterial metabolism were compared. The animals were fed on either a control diet or diets containing 40 g/kg of GOS, FOS or TOS. FOS and TOS were the preferred growth substrates for Bifidobacteria which increased in number by 2 log values in faeces of rats when compared with rats fed on GOS or control diets. Ingestion of TOS specifically induced hydrolysis of the substrate, and did not modify the activity of any other enzymes measured in the caecum. GOS led to a non-specific enzymic induction of beta-galactosidase (EC 3.2.1.23), beta-glucosidase (EC 3.2.1.21) and alpha-glucosidase (EC 3.2.1.20) activities whereas beta-glucuronidase (EC 3.2.1.31) was lowered. Compared with the control group, FOS and TOS diets led to a significant increase in H2 and CH4 excretion; the GOS diet increased only CH4. Analysis of caecal contents revealed a decrease in pH for all diets compared with controls. Total short-chain fatty acid (SCFA) concentration increased significantly in all groups, but the SCFA profile differed between treatment groups. It was concluded that the three oligosaccharides studied had different effects which may be linked to their chemical structure. Some of these effects may be beneficial to human health.
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PMID:Compared effects of three oligosaccharides on metabolism of intestinal microflora in rats inoculated with a human faecal flora. 930 20

The aim of this study was to compare the effects of milk and of various fermented milks on the composition and metabolic activities of the intestinal microflora. Groups of eight rats were fed for 6 wk a diet containing 30% nonfermented milk (M), yogurt (Y), milk fermented with Lactobacillus casei (LcFM) or milk fermented with the association of L. casei DN 114.001 and yogurt starters (LcYFM). In the first study, the survival of the lactic acid bacteria from the fermented milks was assessed by bacterial enumeration in feces of germ-free rats (GF rats) fed milk or fermented milks. The metabolic activities of the lactic acid bacteria were studied in these rats by the measurement of glycolytic activities and products of bacterial fermentation, i.e., acetate and lactate (isoforms L and D). In a second study, the effects of fermented milks on the composition and metabolism [gas, glycolytic activities, short-chain fatty acids (SCFA), alcohol and ammonia] of human flora were studied using human flora-associated rats (HF rats). In GF rats, the survival of L. casei in the feces did not differ between those fed the LcFM and LcYFM diets. L. bulgaricus was detected in the feces of the rats fed Y, whereas Streptoccus thermophilus was found in the feces of the LcYFM group. In HF rats, fecal concentration of Bifidobacteria was greater in the LcFM group than in the others. beta-Glucuronidase (EC 3.2.1.31) activity was lower in rats fed LcFM and Y than in those fed M and LcYFM, whereas beta-galactosidase (3.2.1.23), alpha-glucosidase (EC 3.2.1 20) and beta-glucosidase (EC 3.2.1.21) activities were higher in the LcYFM group compared with the others. Methane excretion was higher in rats fed Y than in other groups. Cecal SCFA concentrations did not differ in LcFM, Y and M groups, but total SCFA, acetate, propionate and butyrate were significantly greater in the LcYFM group. These results suggest that milk fermented with the combination of L. casei and yogurt starters leads to specific effects that are different from the simple addition of the effects found with yogurt and milk fermented with L. casei. These specific effects are potentially beneficial to human health.
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PMID:The association of yogurt starters with Lactobacillus casei DN 114.001 in fermented milk alters the composition and metabolism of intestinal microflora in germ-free rats and in human flora-associated rats. 934 56