Investigation of the Probiotic Properties of Bacterial Strains
Actimel and Yakult were both able to survive the gastric juice. Actimel produced more colonies than Yakult but they both lost the same percentage of viability. The longer the time incubated the more the loss of viability. Introduction: In recent years health promoting functional foods has entered the global market as a result of increased prevalence of lifestyle related diseases (A. A. Aramide et al, 2009). People use functional foods and diet to maintain optimal health. Consumption of probiotics is one of the ways someone could reach and maintain their optimal health.
A probiotic is “living microorganisms, which upon ingestion in certain numbers, exert health benefits beyond inherent basic nutrition” (Todd R. Klaenhammer, 2000). According to the WHO/FAO report 2001 these probiotics can help prevent disorders associated with the gastrointestinal tract, diarrhoea caused by certain pathogenic bacteria and viruses, inflammatory diseases, allergies and a lot more. Actimel and Yakult is a couple of the said probiotic drinks. They claim to increase your body’s natural defences by fighting off the “bad” bacteria. Actimel is a yogurt-type drink produced by a company called Danone™.
It has three strains of bacteria, two traditional yoghurt cultures: Lactobacillus bulgaricus and Streptococcus thermophiles and a third one called L. casei Imunitass® (http://www. actimel. co. uk/About/-WhatIsActimel. aspx, Accessed Feb, 28, 2010). Lactobacillus is a genus of bacteria that aid in the conversion of lactose to lactic acid hence increasing acidity in the stomach making it hard for harmful bacteria to survive (http://en. wikipedia. org/wiki/Lactobacillus, Accessed Feb 28, 2010). Actimel contains 10 billion L. casei Imunitass® bacteria per 100ml bottle.
This bacterial strain works under a wide range of pH and temperature hence able to survive the acidic conditions in the stomach. This ensures that the bacteria reach the gut alive and active. It helps by topping up the good bacteria in the stomach and making it hard for the germs to survive. The bacteria also aids in strengthening the gut wall so that only certain nutrients can pass. In 2004 a trial carried out to find the effect of Actimel on the immune response of subjects under academic examination stress showed that Actimel was able to control the number of lymphocytes and CD56 cells in subjects under academic examination stress.
Other studies also show that the Actimel bacterial strains can be used in treating allergic rhinitis, prevention of diarrhoea and induce immune responses. On the other hand Yakult is milk based probiotic and contains only one strain of bacteria: Lactobacillus casei Shirota. It is produced and distributed by Yakult Honsha Co. Ltd. It contains 6. 5 billion L. casei Shirota per 65ml bottle. A variety of scientific studies have shown that Yakult has an effect on the human NK-cell activity, intestinal micro flora and immune parameters in humans.
This sequence was then run through the BLAST analysis to identify the probiotic isolate. Discussion: A Probiotic must be able to survive the conditions of the stomach and pass through to the gut without significant loss. The bacteria found in the probiotics are cultured on petri dishes to test the amount of colonies present in the product. As mentioned above Actimel contains 10 billion per 100 ml and Yakult contains 6. 5 billion per 65 ml. From the t-test there was no significant difference in the content of the two products (Table 1). This was due to the fact that they both contain 100 million bacteria per ml of product. From the gram stain images both Actimel and Yakult was stained with the same conditions.
But Yakult had only one stain whereas Actimel had two different stains. This is due to the fact that there is more than one species of bacteria in Actimel. The colour of the staining represents two different types of bacteria: gram-negative and gram-positive. All species of the lactobacillus genus are gram-positive. Gram-positive organisms retain the stain when they are stained with crystal violet but gram negative organisms lose their purple/violet stain when washed with alcohol but when retain safranin stain. Therefore the Yakult contains only gram positive bacteria (L. casei Shirota®) while Actimel contains both gram positive and gram negative bacterium (Figure 1). From the survival studies we can