I would ask: check it for what activity? Do you need to check that it can grow, colonize, compete, produce toxins, produce biofilm? Each is a different assay; also, there may be some in vivo assays you could tailor in model organisms, depending on the probiotic and its intent. The paper http://www.plospathogens.org/article/info%3Adoi%2F10.1371%2Fjournal.ppat.1002995

demonstrates the subtlety of an effective probiotic that targets a specific in vivo environment and how activity was judged in vivo.

You need to check if your strain is resistant to gastric acids (HCl+trypsin), bile salts, is able to adhere to enterocytes (Caco-2 cell line) and/or mucus (is able to compete for space or displace pathogens from Caco-2 surface), produces hydrogen peroxide, bacteriocins (test on intestinal pathogenic strains). Later you need to go to in vivo tests.

You are going to evaluate pro biotic efficacy/potential of a strain,first of all you must check its in vitro Acid & Bile tolerance,then cell adherence test,growth inhibitory activity against pathogenic organism,cholesterol removal etc.Then go for in vivo tests

The above said are screening criterion's for probiotic bacteria. You are looking for probiotic activity........I think you need to perform co-aggregation with pathogens, vitamin production, bacteriocin production like activities.

@jayesh sir, they have need of in vitro probiotic assay and you have suggested anti-pathogen assay.Pathogen co-aggregation means-compition for site attachement.bacteriocin production means invading of pathogen.But in vivo there is different environment & in such environment probiotics organism must remain viable and active.So i think you suggested expt. is not sufficient.

There are several means to check probiotic activity. It depends on what you are interested ultimately. When you say probiotic activity, I assume that you have cleared your strain for all essential criteria of probiotics as listed in WHO guideline. If you want to check antagonistic activity of your probiotic strain in vitro, I would suggest you to design the experiment where you can mimic all in vivo conditions. For example, competitive inhibition, adhesion inhibition, displacement, invasion assay. All these experiments will give you broad view on ability of your probiotic candidates. Although in vitro assays are not completely reliable but they certainly give you a lot information for in vivo predictions. And I would suggest you that make your experiment model as complex as possible to produce as much similarity with in vivo conditions. For example, use of intestinal epithelial cell lines with mucin, co-culture of two cell lines, etc. Similarly, you can design experiment for immunomodulatory activity of probiotic strains.

Hai,

according to the FAO/WHO the organism must fulfill the certain criteria to regarded as a potential probiotic strains, which includes tolerate to the stimulated gastric conditions, bile conditions, capability of prevent the growth of enteric pathogens by producing several organic acids and bacteriocins, susceptible to the commonly used antibiotics, beside these several other properties like adhesion to epithelial cells, invitro cholesterol reduction assasy, bile salt hydrolase activity also performed to evaluate the probiotic potential of the organisms.

Most of the things have been suggested by researchers above. I am also attaching one of official document for the guidance. I hope it will be useful!

According to mechanisms action of probiotics ,in vitro there are more than assay to check the activity of probiotics strains like acid and bile tolerance,antibiotic susceptibility and antimicrobial activity (production of bacteriocins).

also I attaching one PDF research , I hope it will be useful.

Following

Adhering strictly to WHO definition of probiotic there is no in vitro assay that could check probiotic action of microorganism. Probiotic action can only be proved in clinical trial. You can only indicate a probiotic potential in an in vitro assay and it depends on its specific activity, eg. boosting immune activity - an assay for stimulation of immune cells, alleviating lactose intolerance - beta-galactosidase assay to show significantly higher activity than of any other strains, etc. Tolerance to low pH, bile salts (gastric juice), and etc. often mentioned by others show only useful traits that make a strain easier to introduce to GI tract and other traits useful in production of dietary supplement or medical formulation.

I recommend to read Expert consensus document. The

International Scientific Association for Probiotics and Prebiotics consensus

statement on the scope and appropriate use of the term probiotic. Nat Rev

Gastroenterol Hepatol. 2014 Aug;11(8):506-14. doi: 10.1038/nrgastro.2014.66. https://www.nature.com/articles/nrgastro.2014.66