Oral administration of Lactobacillus gasseri TMC0356 stimulates peritoneal macrophages and attenuates general symptoms caused by enteropathogenic Escherichia coli infection.
BACKGROUND
Enteropathogenic Escherichia coli (EPEC) is an important cause of diarrhea in human. This study was conducted to investigate the ability of orally administrated probiotic lactobacilli to protect hosts from EPEC infection via enhancement of immune responses.


METHODS
Lyophilized Lactobacillus gasseri TMC0356 (TMC0356) was orally administered to Institute of Cancer Research (ICR) mice and Sprague Dawley (SD) rats for 11 and 7 days, respectively. These tested mice and rats were intraperitoneally injected with EPEC. Body weight, general symptoms (piloerection, soft stool, diarrhea, and anal hyperemia), and mortality of the tested mice were observed. Peritoneal macrophages were extracted from peritoneal cavity of tested rats, and their phagocytosis and cytokine production were analyzed.


RESULTS
Oral administration of TMC0356 accelerated the disappearance of general symptoms and reduced mortality of EPEC-infected mice in the early phase. Peritoneal macrophages from rats orally administered with TMC0356 showed significant increases in phagocytic activity (p < 0.05) and interleukin (IL)-6 production (p < 0.01) compared to those from control rats. Tumor necrosis factor-α and production of IL-1β, IL-10, and IL-12 slightly increased, although the changes were not statistically significant.


CONCLUSIONS
These results suggest that some of selected probiotic lactobacilli may, at least partly, protect hosts from EPEC infection by the enhancement of innate immunity of host and attenuate symptoms caused by the infection.
Technical Research Laboratory, Takanashi Milk Products Company Limited, Asahi-ku, Yokohama, Kanagawa, Japan.
Kazutoyo
K
Yoda
Technical Research Laboratory, Takanashi Milk Products Company Limited, Asahi-ku, Yokohama, Kanagawa, Japan. Electronic address: he-fang@takanashi-milk.co.jp.
Fang
F
He
Technical Research Laboratory, Takanashi Milk Products Company Limited, Asahi-ku, Yokohama, Kanagawa, Japan.
Manabu
M
Kawase
Technical Research Laboratory, Takanashi Milk Products Company Limited, Asahi-ku, Yokohama, Kanagawa, Japan.
Kenji
K
Miyazawa
Technical Research Laboratory, Takanashi Milk Products Company Limited, Asahi-ku, Yokohama, Kanagawa, Japan.
Masaru
M
Hiramatsu
D000284:Administration, Oral; D000818:Animals; D001835:Body Weight; D004195:Disease Models, Animal; D054308:Enteropathogenic Escherichia coli / Q000276:immunology*; D004927:Escherichia coli Infections / Q000276:immunology / Q000473:pathology*; D007155:Immunologic Factors / Q000008:administration & dosage*; D007778:Lactobacillus / Q000276:immunology*; D017737:Macrophages, Peritoneal / Q000276:immunology*; D008297:Male; D008813:Mice, Inbred ICR; D010538:Peritonitis / Q000276:immunology / Q000473:pathology*; D019936:Probiotics / Q000008:administration & dosage*; D017207:Rats, Sprague-Dawley; D016896:Treatment Outcome
D007155:Immunologic Factors