Influence of Lactic Acid Bacteria on Longevity ofCaenorhabditis elegansand Host Defense againstSalmonella entericaSerovar Enteritidis

Abstract

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 of Escherichia 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 of Salmonella 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 of C. elegans and prolong life span. The nematode appears to be an appropriate model for screening useful probiotic strains or dietetic antiaging substances.

Probiotic properties of lactic acid bacteria isolated from traditionally fermented Xinjiang cheese

“…Feeding of L. rhamnosus R4 has effectively increased the mean lifespan of C. elegans, and the life extension rate reached a maximum of 36.1%. This is in accordance with the results described by Ikeda et al (2007), in which feeding nematodes with bifidobacteria or lactobacilli caused increased average lifespans compared to those fed with OP50 and the life extension rates ranged from 17% to 33%. These results suggested that different strains show diverse impacts on lifespan extension.…”

“…The effect of selected LAB strains on longevity in C. elegans was examined using the killing assay as described by Ikeda et al (2007), with slight modifications. Briefly, the synchronized worms were grown at 20 °C until they reached L4 stage.…”

“…Ikeda et al (2007) have reported that LAB may contribute to host defenses and prolong the lifespan of C. elegans. In this study, we wished to evaluate potential traits of probiotic strains selected from Xinjiang cheese products using in vitro tests and the in vivo C. elegans model.…”

Effects and mechanisms of prolongevity induced by Lactobacillus gasseri SBT2055 in Caenorhabditis elegans

“…Ikeda et al . (2007) have also studied the effects of different probiotic strains in C. elegans , including Bifidobacterium , Lactobacillus helveticus , and Lactobacillus plantarum . Immune‐stimulating molecules, such as peptidoglycan (Lebeer et al ., 2010), S‐layer protein (Konstantinov et al ., 2008), and exopolysaccharide (Kim & Kim, 2009; Kim et al ., 2010) exist on the cell surfaces of these bacteria.…”

Evaluation of Caenorhabditis elegans as the Host in an Infection Model for Food-borne Pathogens

“…elegans is useful for studying the relationship between innate immunity and pathogens because the nematode lacks an adaptive immune system. Using the worms on agar plates containing no bacterial nutrients, we recently found that lactic acid bacteria can enhance the host's defense against salmonella in C. elegans and prolong lifespan 13) . Although C. elegans does not have phagocytes specialized for innate host defense, it produces a variety of humoral antibiotic substances such as lysozymes, caenopores, lipase, lectins and C3-like thioester-containing proteins, and defensin-like antibiotic peptides 1,18,20,25,26) .…”