Effects of the Consumption of Heat-killed Enterococcus faecalis EC-12 Preparation on Microbiota and Metabolic Activity of the Faeces in Healthy Adults

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Terada, Atsushi ; Bukawa, Wakoto ; Kan, Tatsuhiko ; Mitsuoka, Tomotari (2011)
  • Publisher: Microbial Ecology in Health and Disease
  • Journal: Microbial Ecology in Health and Disease (issn: 1651-2235)
  • Related identifiers: doi: 10.3402/mehd.v16i4.7922

The effects of the consumption (200 mg/day) of heat-killed Enterococcus faecalis EC-12 preparation (EC-12) for 14 days on microbiota and metabolic activity of the faeces were studied in eight healthy volunteers (22-26 years of age). During EC-12 consumption, the counts of bifidobacteria (p<0.05 on day 7 and p<0.01 on day 14) were significantly increased, except for the numbers of bifidobacteria in one volunteer, whereas the counts and the frequency of occurrence of lecithinase-positive clostridia (p<0.05), including Clostridium perfringens, were significantly decreased, when compared with the values before EC-12 consumption and during placebo consumption. The decreased tendency in the counts of Enterobacteriaceae and the increased tendency in the levels of lactobacilli was observed during EC-12 consumption, compared with the values before EC-12 consumption and during placebo consumption. No detectable changes occurred in the counts of other organisms throughout the experimental periods. The total faecal volatile fatty acid and acetic acid (p<0.05 on day 7 and p<0.01 on day 14) during EC-12 consumption, and succinic acid (p<0.05), lactic acid (p<0.05) and propionic acid (p<0.05) on day 14 of EC-12 consumption were significantly increased when compared with the values before EC-12 consumption and during placebo consumption. Faecal concentrations of ammonia, phenol and p-cresol (p<0.05) were significantly decreased on day 14 of EC-12 consumption. Faecal levels of sulfide and indole (p<0.05) were significantly decreased during EC-12 consumption. Faecal values of oxidation-reduction potential (ORP; p<0.05 on day 7 and p<0.01 on day 14) were significantly decreased during EC-12 consumption. Faecal pH values tended to decrease on day 14 of EC-12 consumption. Stool weight and water content were slightly increased during EC-12 consumption. The odour of the faeces was slightly reduced during EC-12 consumption.Key words: Enterococcus faecalis EC-21, faecal microbiota, faecal metabolic products, heat-killed bacteria.
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