I have some bacterial strains & I would like to test these for their probiotic efficacy. Can anyone suggest an in vitro assay which can be done step by step?
I would suggest you to follow the FAO/WHO document issued in 2006 (FAO Food and Nutrition Paper nº 85) entitled. Probiotics in Food: Health and Nutritional Properties and guidelines for evaluation. This document inlcudes the reports of 2 expert groups dealing with the topic.
first take five aniamals having about similar in sex and age and weight. of which two are kept as control (positive control and negative control). and you can do the experiment on remaining three animals. then take your bacterial culture (single culture or you can made consortium) and add diluent as lactose or fructose in that and these formulation feed to the three animal. and at some standard time you can collect the fecal matter of all the five animals and determine the Total microbial count of all samples. and you can also determine the weight of the three animal against the control animals.
Find out what type of bacteria you need for treating your condition. Different strains are beneficial for different types of conditions. Look for the particular strain that clinical studies have shown to be beneficial for your condition. For instance, the University Of Maryland suggests using probiotics that contain the strain Lactobacillus acidophilus for treating yeast infections, recommending 1 to 10 billion cultures per day.
Step 2
Look for the word "probiotic" on the product label to be sure you are not looking at another health product, such as vitamin supplement.
Step 3
Look on the product's label for "colony forming units," or CFU, which is the amount of bacteria strain it contains. This is the amount of probiotics contained in the product. In order for the probiotic to be beneficial, it must have the same amount or more of the beneficial microorganisms than the amount clinical studies have shown to be beneficial for your condition.
Step 4
Look for the "live & active cultures," or LAC, seal on the product. The National Yogurt Association established a seal that is easy to identify on a product's label so you can be sure you are getting a quality product that meets the highest standards for probiotic supplements. The seal represents five features of the product: at least one clinically proven strain, the amount of organisms per serving, health benefits, storage of product and company contact information.