Efficacy of Lactic Acid Bacteria (LAB) supplement in management of constipation among nursing home residents

BACKGROUND

Constipation is a significant problem in the elderly, specifically nursing home and/or extended-care facility residents are reported to suffer from constipation. Lactic acid bacteria (LAB) are beneficial probiotic organisms that contribute to improved nutrition, microbial balance, and immuno-enhancement of the intestinal tract, as well as diarrhea and constipation effect. The objective of this study was to investigate the efficacy of this LAB supplement in the management of nursing home residents.

METHODS

Nineteen subjects (8M, 11F; mean age 77.1 +/- 10.1) suffering with chronic constipation were assigned to receive LAB (3.0 x 10(11) CFU/g) twice (to be taken 30 minutes after breakfast and dinner) a day for 2 weeks in November 2008. Subjects draw up a questionnaire on defecation habits (frequency of defecation, amount and state of stool), and we collected fecal samples from the subjects both before entering and after ending the trial, to investigate LAB levels and inhibition of harmful enzyme activities. Results were tested with SAS and Student's t-test.

RESULTS

Analysis of questionnaire showed that there was an increase in the frequency of defecation and amount of stool excreted in defecation habit after LAB treatment, but there were no significant changes. And it also affects the intestinal environment, through significantly increase (p < 0.05) fecal LAB levels. In addition, tryptophanase and urease among harmful enzyme activities of intestinal microflora were significantly decreased (p < 0.05) after LAB treatment.

CONCLUSION

LAB, when added to the standard treatment regimen for nursing home residents with chronic constipation, increased defecation habit such as frequency of defecation, amount and state of stool. So, it may be used as functional probiotics to improve human health by helping to prevent constipation.

Bicyclomycin sensitivity and resistance affect Rho factor-mediated transcription termination in the tna operon of Escherichia coli

The growth-inhibiting drug bicyclomycin, known to be an inhibitor of Rho factor activity in Escherichia coli, was shown to increase basal level expression of the tryptophanase (tna) operon and to allow growth of a tryptophan auxotroph on indole. The drug also relieved polarity in the trp operon and permitted growth of a trp double nonsense mutant on indole. Nine bicyclomycin-resistant mutants were isolated and partially characterized. Recombination data and genetic and biochemical complementation analyses suggest that five have mutations that affect rho, three have mutations that affect rpoB, and one has a mutation that affects a third locus, near rpoB. Individual mutants showed decreased, normal, or increased basal-level expression of the tna operon. All but one of the resistant mutants displayed greatly increased tna operon expression when grown in the presence of bicyclomycin. The tna operon of the wild-type drug-sensitive parent was also shown to be highly expressed during growth with noninhibitory concentrations of bicyclomycin. These findings demonstrate that resistance to this drug may be required by mutations at any one of three loci, two of which appear to be rho and rpoB.

Effects of apple pectin on fecal bacterial enzymes in azoxymethane-induced rat colon carcinogenesis

Because of the potential significance of colonic bacteria in colon carcinogenesis, we investigated the effect of pectin of different types on fecal bacterial enzymes (beta-glucuronidase, beta-glucosidase and tryptophanase) at various periods of time after feeding rats with pectin-containing diets during azoxymethane-induced colon carcinogenesis. The diet supplemented with 20% apple pectin or 20% citrus pectin decreased the multiplicity of colon tumors, and the number of tumors was significantly decreased in the group fed apple pectin. The incidence of colon tumors in the apple pectin group was lower than that in the control group. The mean tumor size was similar among the three groups. Apple pectin feeding decreased fecal beta-glucosidase and tryptophanase levels. Furthermore, a significant decrease in the activity of beta-glucuronidase was observed in the apple pectin group during the initiation phase. These findings suggest that the protective effect of pectin on colon carcinogenesis may be dependent on the type of pectin and be related to the decrease of beta-glucuronidase activity in the initiation stage of carcinogenesis.