The functionality of the bacteria in Megaflora
Two different ways are used to ensure the existence of a consistent number of bacteria inside the bowel.
The first one consists in administrating first a great quantity of bacteria which will weaken its activity and reduce its quantity during the conservation, but also during the cold storage. During this period, the high mortality rate of probiotics can be possibly caused by their passage into the gastrointestinal tract and therefore we do not know what the real number of intact bacteria that reaches the bowel is.
The second method is to ensure that during the product shelf life, the number of bacteria does not change and that at any time this latter can survive to the intestinal tract and ensure the right implantation in the intestinal mucosa carrying out a lacto-fermentative activity.
On this point, a study on real-time stability of different Megaflora 9 samples has been carried out, such samples have been stored at ambient temperature (25º C) in its original package. This study has been carried out between 2002 and 2006 using samples to count the number of viable bacteria.
Real time stability test Megaflora 9
The efficacy of a probiotic product depends on the total viable bacterial cell count in the product. Storage of the product should not negatively influence this total viable cell count, since it will harm the effectiveness of the product. For this reason, shelf-life of probiotic products is based on the total viable cell counts after different periods of time of storage. The best method to measure the total viable cell count in time is the Real Time Stability (RTS) test. The total viable cell count is expressed in colony forming units (cfu) per gram.
In RTS tests, samples of the product are stored at 25°C ± 2°C and 60% relative humidity for a period of four years. On regular times the total cell count of the product is measured. Samples are tested on cell count every three months during the first year, and every 6 months during the second year. So the time of measurement is at t = 0, 3, 6, 9, 12, 18, 24 and 48. For each point in time, a separate closed aluminum sachet containing the product is used. Therefore at the start of the test 8 separate sachets are stored under the above mentioned conditions. The measurements are always done in duplex.
In Figure 1 you can find the results of Megaflora 9, which has a specification of 1 x 109 cfu/gram.
To interpret the data, it is important to realize that probiotic bacteria are living organisms. Total viable counts are done by plating ten-fold dilutions and counting cfu’s after a specified period of incubation. There are certain allowed margins of error in the measurements. The accepted margin of error in measuring total viable cell count is log 0,4. This means that in the case of Megaflora 9, which has a specification at 1 x 109 cfu per gram (= LOG 9), the accepted margin of error lies between 4 x 108 (= LOG 9 – 0,4) and 2.5 x 109 (= LOG 9 + 0,4) cfu per gram. In Figure 1 we have included these upper and lower lines of the margins of error. These are represented by red, dotted lines. Results of analyses that fall between those lower and upper margins are considered to be correct and according to the set specifications for Megaflora 9.
Based on the results of the RTS test Megaflora9 has a shelf life of 4 years.