My Thesis: CONCLUSION AND FUTURE PERSPECTIVES

CHAPTER 5

CONCLUSION AND FUTURE PERSPECTIVES

 

Although several probiotic strains have been identified with health benefits, for a strain to be beneficial, it must fulfill certain criteria to be considered a valuable food to exert a positive influence. The present study was undertaken to evaluate the viability of pharmaceutical probiotic products upon reaching consumer and the survival of this probiotics to low pH. In fact, low pH is the initial critical condition encountered by the probiotics upon ingestion. Throughout the study, all the products did not meet the claimed viability. Nevertheless, two of the product (A and B) meet the minimum requirement for probiotic products (CFU/g) whereas product C did not. Product B has the highest viability and highest acid tolerance whereas product C has the lowest viability and lowest acid tolerance. The loss of viability of probiotics at low pH corresponds to its acid tolerance and hence, low pH affects the viability to a certain extent. The viability of probiotic was affected by acidic condition (pH 2, 3 or 4) and unaffected by slightly acidic condition (pH 6).

 

The products tested in this study are similarly manufactured as freeze-dried forms but the level of acid tolerance was not similar among these products. This indicates that the acid tolerance of probiotics in the product was varied in their ability to tolerate low pH. Product C confer poor tolerance to low pH suggested that the overall of probiotic strains found in the products were not tolerant to low pH whereas product B confer good tolerance to low pH suggested that the overall of probiotic strains found in the products were tolerant to low pH.

 

The acid tolerance exhibited by probiotics of product A was not good as compared to product B. Product B was better tolerant to low pH compared with product, which indicate that the application of a consortium of strains were more likely to possess better acid tolerance. Moreover, given that the human stomach is a hostile environment, it appears unlikely that a single probiotic bacterial strain will be capable of influencing the microbial ecology of the host and of beneficially affecting the host. Hence, it is essential that these probiotic strains not be developed as individual entities but rather as the active ingredients of the food products that are ultimately intended for human consumption.

 

The apparent poor results of this study indicate that several pharmaceutical probiotics could successfully transit the human stomach and may be capable of reaching the intestinal environment and functioning effectively in the intestine. However, criterion of acid tolerance for this in vitro selection could not reveal the capability of probiotic strains individually. Likewise, this is also the limitation of this study whereby selective enumeration of probiotics was used for L. acidophilus and L. casei. The bifidobacteria did not enumerated differentially from the total anaerobes because lack of reliable a selective media. Thus, the tolerable pH of bifidobacteria could not be determined and the acid tolerance of pharmaceutical probiotics is not fully understood. Moreover, the limitation of fund also restricts the uses of biochemical test such as API kit to further confirm the identity of species.

 

In conclusion this in vitro test provides an initial understanding on the acid tolerance of pharmaceutical probiotics. From this set point, in vitro acid tolerance test allow the continuation on in vivo test to fully investigate the tolerance of probiotics in human stomach. Concurrently, acid tolerance is recommended to proceed for the bile tolerance test as the second criteria.