Antigenotoxic properties of lactic acid bacteriain vivoin the gastrointestinal tract of rats

Abstract

In view of the high incidence of dietary-related tumors, one important research goal is to identify the participating genotoxic carcinogens and the nutritional factors that may counteract their activities. We therefore have further developed a method to assess DNA damage in tumor target tissues of the gastrointestinal tract. Subsequently the prevention of this inducible DNA damage by lactic acid bacteria and by milk products fermented with probiotics was studied as well. The microgel electrophoresis technique was applied to cells of the esophageal, gastric, duodenal, and colonic mucosa. Cells were grouped according to their degree of DNA damage, the simplest measure of which is to discriminate between those with damage (comets) and those without damage. When these cells were isolated from animals treated with a genotoxic carcinogen, N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), and exposed to MNNG for 1-24 hours, it was possible to follow the course of genotoxicity throughout the gastrointestinal tract. After the animals were treated with the lactic acid bacteria under study, it was possible to detect antigenotoxic properties as well. The gavage of 10(10) viable Lactobacillus casei cells in 10 ml of 0.9% NaCl per kilogram body weight immediately before the oral administration of MNNG (5 mg/kg body wt) resulted in a reduction of induced DNA damage in gastric and colonic mucosa cells. A sequential treatment schedule was even more effective: when the animals were treated orally with lactic acid bacteria or yogurt (10 ml/kg body wt) in the morning followed by MNNG (7.5 mg/kg body wt) eight hours later and the colon cells were isolated 16 hours later, the percentages of cells remaining intact were distinctly higher in the combination groups (68 +/- 10 and 68 +/- 19 for L. casei and a "Bio" yogurt, respectively) than in the group receiving only MNNG (45 +/- 17). The effect of heating L. casei was studied and was found to yield less clear-cut effects in preventing genotoxicity. The method is an efficient tool to elucidate antigenotoxic properties of food components in vivo in those target tissues actually afflicted by dietary-related tumors.

Modulatory activity of a Lactobacillus casei strain on 1,2‐dimethylhydrazine‐induced genotoxicity in rats

“…Lactic acid bacteria (LAB) and their fermented products are thought to confer a variety of important nutritional and therapeutic benefits (e.g., relief of lactose maldigestion, antidiarrhoeal capabilities) [Tuohy et al, 2003]. Moreover, some fermented dairy products and/or LAB have demonstrated antimutagenic/antigenotoxic acti-vities both in vitro and in vivo [Bodana and Rao, 1990;Renner and Munzner, 1991;Hayatsu and Hayatsu, 1993;Pool-Zobel et al, 1993a,b, 1996Villarini et al, 1997;Villarini and Pasquini, 1999] as well as antitumor properties [Hirayama and Rafter, 1999;Wollowski et al, 2001].…”

Effect of dietary intervention with different pre- and probiotics on intestinal bacterial enzyme activities

“…Bifidobacteria and lactobacilli are the most widely studied probiotic genera and have been shown to exert cancer protective effects in vitro and in vivo (Lidbeck et al, 1992;Pool-Zobel et al, 1993). These organisms have low activities of enzymes involved in the conversion of procarcinogens into potentially carcinogenic compounds (Nakamura et al, 2002).…”

Effects of Lactic Acid Bacteria (Lab) Supplement on The Growth Rate and Elimination of Enteropathogenic Bacteria in Calves

“…And, the numbers of fecal beneficial and pathogenic bacteria were minimally affected by treatments under the conditions of this experiment. it has also been observed that the oral administration of Bifidobacterium or Lactobacillus organisms improved birth weight gain and mortality in calves fed probiotic supplements compared with control animals (1,23).…”