**5. Conclusions**

232 Lactic Acid Bacteria – R & D for Food, Health and Livestock Purposes

spp. and *Bifidobacterium* spp.

Sivieri et al [123]

days of the experiment, to determine the viable cell counts of total aerobic and anaerobic bacteria, *Enterococcus* spp., Enterobacteria, *Lactobacillus* spp., *Clostridium* spp., *Bacteroides* 

**Figure 2.** Topographic view of macroscopic growths by G2 – Induced with DMH. Sivieri et al [123]

**Figure 3.** Topographic view of macroscopic growths by G3 – Induced with DMH + *E. faecium* CRL 183.

By day T30 days of experiment, rats on a red meat-based diet exhibited an increase in the population of total anaerobes, enterobacteria and enterococci and a decrease in the numbers of lactobacilli and bifidobacteria. From T30 to T60, the obtained results showed that fermented soy product and pure *Enterococcus faecium* CRL 183 suspension promoted an increase in the numbers of lactobacilli (0.45 log CFU g−1 and 1.83 log CFU g−1, respectively). During the same period, only the animals treated with pure *Enterococcus faecium* CRL 183 suspension showed a rise in the fecal bifidobacterium population. The fermented soy product promoted a slight fall in the *Bacteroides* spp. population (2*.*80 ± 0*.*20 to 2*.*34 ± 0*.*07 log

CFU g−1), but the counts of *clostridia*. and enterobacteria were unchanged.

From the above discussion, it is evident that probiotics have the capacity to modulate the intestinal microbiota and the immune system, to the benefit of the host organism, reducing the risk of many chronic degenerative diseases, among them colon cancer. It appears also that the actions performed by probiotics are species-strain-dependent, so that several effects or actions can occur with the same bacterial genus. However, the results of several experiments reported in the literature, highlight a degree of controversy concerning the effects observed, especially regarding the various types of cancers and it is difficult to compare these studies. Such controversies are due mainly to large variations in the time of the experiment - usually prevailing those of short duration the experimental models, bacterial strains and the doses and frequencies of administration of probiotics. In this sense, it is important that further studies be done to define and standardize these variables mentioned, and especially to elucidate the mechanisms involved in each of the observed effects.

It showed also be mentioned that, according there is also in the literature, that probiotics studied are taken almost exclusively in milk as can be observed in the products available on the market. This condition often makes them inappropriate for certain lactose intolerant population groups on those and allergic to milk proteins. Thus, alternative vehicles for probiotics, free of lactose and of β-lactoglobulin, such as the aqueous extract of soybeans, for example, deserve special attention from researchers seeking to develop products with a good nutritional profile and suitable to transport the probiotic specified for the purpose desire. It is expected that in the near future, as results of the interaction of various fields of study such as food science and technology, nutrition, microbiology, genetic engineering and molecular biology the market can offer consumers products that are more accessible and effective, reducing the risk of certain diseases, particularly certain types of cancer, and acting as adjuvants in specific treatments for existing diseases.

Finally, from the results obtained by our research group in the studies of probiotics in relation to colon cancer, and even other diseases, it appears that these was always variability between individuals, either in clinical trials or in studies with animal models, suggesting a possible specificity of these individuals in relation to consumption of given probiotics. This leads us to wonder, if today nutrigenomics is already a reality, is it not the moment to propose studies on something like "probiogenomics" or even about self-probiotics? Certainly the future will provide an answer to that question

Probiotics and Intestinal Microbiota: Implications in Colon Cancer Prevention 235

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