Open AccessInfluence of Lactic Acid Bacteria on Longevity ofCaenorhabditis elegansand Host Defense againstSalmonella entericaSerovar Enteritidis
Author(s) -
Takanori Ikeda,
Chikako Yasui,
Kaori Hoshino,
Kentaro Arikawa,
Yoshikazu Nishikawa
Publication year - 2007
Publication title -
applied and environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.552
H-Index - 324
eISSN - 1070-6291
pISSN - 0099-2240
DOI - 10.1128/aem.00704-07
Subject(s) - biology , salmonella , salmonella enterica , host (biology) , microbiology and biotechnology , salmonella enteritidis , serotype , caenorhabditis elegans , nematode , probiotic , bacteria , listeria monocytogenes , ecology , biochemistry , genetics , gene
This study aimed to develop a convenient model to investigate the senescence of host defenses and the influence of food and nutrition. A small soil nematode,Caenorhabditis elegans , was grown for 3 days from hatching on a lawn ofEscherichia coli OP50 as the normal food source, and subsequently some of the nematodes were fed lactic acid bacteria (LAB). The life spans of worms fed LAB were significantly longer than the life spans of those fed OP50. To investigate the effect of age on host defenses, 3- to 7-day-old worms fed OP50 were transferred onto a lawn ofSalmonella enterica serovar Enteritidis for infection. The nematodes died over the course of several days, and the accumulation of salmonella in the intestinal lumen suggested that the worms were infected. The 7-day-old worms showed a higher death rate during the 5 days after infection than nematodes infected at the age of 3 days; no clear difference was observed when the worms were exposed to OP50. We then investigated whether the LAB could exert probiotic effects on the worms' host defenses and improve life span. Seven-day-old nematodes fed LAB from the age of 3 days were more resistant to salmonella than worms fed OP50 until they were infected with salmonella. This study clearly showed that LAB can enhance the host defense ofC. elegans and prolong life span. The nematode appears to be an appropriate model for screening useful probiotic strains or dietetic antiaging substances.