I am sure you've heard this before: "Everybody needs to take probiotics. And our brand is exactly what you need."
What are the probiotics? They are live microorganisms that confer a health benefit on the host (you) when administered in adequate amounts.
To experience suffient health benefits from probiotic supplementation, it’s important to understand which attributes make a probiotic effective.
Before determining which probiotics, the source, and the amounts, it is important to understand why we need them.
It is necessary to identify the specific genus, species, and strain of probiotics.
You also need to be aware of the clinical research that supports the use of those strains for the specific targeted health conditions, not just promotional materials that you see advertised online or in the accompanying brochures.
Probiotics are often used for general health, to treat some illnesses or as a means to restore, replace "good bacteria" after an illness or use of antibiotics.
Probiotics can be consumed in supplemental form and/or by eating fermented foods, which naturally contain live cultures. Some research has shown that probiotics must contain a minimum of 10 million colony forming units (CFU) per gram at the time of consumption to provide the associated health benefits. [1,2]
Since probiotics are complex microorganisms that are sensitive to heat, light, moisture, air, and acidic environment of the stomach, proper processing, storage and ways to take probiotics are key to ensure their survival and benefits. 
The quantity and strains of a probiotic don’t matter, if they are not stable. A good manufacturer will have testing on file and can verify that the product has met all requirements to ensure the product remains stable throughout its shelf life, when stored according to the label directions. Look for a supplement that lists an expiration date. Expiration dating is not a labeling requirement for supplements, so a manufacturer who provides one is making the claim that the CFU count provided at the time of manufacturing, holds true to the expiration date.
Gas and light permeability through the packaging can influence the survival of probiotics. 
Probiotic supplements are typically packaged in opaque material to protect them from light and oxygen.
Also note the storage requirements. Almost all probiotics used to require refrigeration; however, new processing techniques, like dry freezing, have allowed some probiotics to be stored at room temperature.
Probiotics are popular thanks to a rich research environment of microbiota, microbiome, and emerging human clinical data. This data is very complex and controversial. New publications on a specific strain's benefits get published almost daily. Yet there are still a lot of unanswered questions. Some studied products may contain a single species (precision probiotics) or they could contain a broad spectrum (combination of genera in its most diverse form or different strains of the same species in one formula.)
Examples of well studied products include:
Lactobacillus plantarum 299v and Bifidobacterium breve for Irritable Bowel Syndrome;
Lactobacillus Plantarum 8702 and Lactobacillus Plantarum Heal 9 for cold and flu-like symptoms to support the immune system;
Lactobacillus Acidophilus (NCFW), Bifidobacterium Lactis (Bi-07), Bifidobacterium Lactis (Bi-04), and Lactobacillus Paracasei (Lpc-37) in combination for antibiotics induced diarrhea.
Unfortunately, there are many more strains that are on the market with minimal data to support their use.
Probiotics can range up to 900 billion CFUs (with most products in the 1 to 50 billion range).
But how many CFUs are necessary for the intended health benefit? That’s largely unanswered, but information continues to be published in this regard.
These delivery systems vary greatly in effectiveness to exert health benefits for a patient.
Probiotic delivery systems can be categorized into:
The degree of health benefits, provided by the probiotic formulations, varies in their ability to deliver viable, functional bacteria in large enough numbers (effectiveness), to provide protection against the harsh effects of the gastric environment and intestinal bile, and to survive formulation processes.
Capsules and tablets are currently the preferred dosage forms, since they can provide protection from the environment and help to deliver probiotics to the targets: stomach, small intestines or colon. The concern with tablets, however, is the heat production that occurs during compression with temperatures reaching up to 60°C, which can destroy bacteria that are most viable at their optimal temperatures. 
With commercial food products, cheeses have been commonly used as carriers for probiotic delivery.
Kefir and yogurt use has dated back centuries, with the first documented article of bacterial supplementation published in the early twentieth century by Nobel Prize winner Elie Metchnikoff.
Chocolate can be used to protect and deliver probiotics as well as other gastro-sensitive products.
The benefits of using natural products are that bacteria are being delivered naturally and with prebiotics and probiotics, i.e. nutrition that helps microbes to survive. 
There are also soil-based, spored probiotics that are not sensitive to the presence of oxygen, UV light and other chemicals found in the natural environment. These can survive the acidic stomach environment and become functional in the oxygen free milieu of the intestines.
Dose, type, delivery, preparation, packaging, and storage are all decision factors in regards to probiotics. Which means that the innocent question of “what’s the best probiotic?” quickly becomes complex.
For more information on prebiotics, probiotics and other health related issues please schedule an appointment with Dr. Koganski at 215-750-7000 or www.newtowninternalmedicine.com.
1) Chaikham P. Stability of probiotics encapsulated with Thai herbal extracts in fruit juices and yoghurt during refrigerated storage. Food Bioscience. 12/1/ 2015;12:61-6.
2) Sah BNP, et al. Effect of refrigerated storage on probiotic viability and the production and stability of antimutagenic and antioxidant peptides in yogurt supplemented with pineapple peel. Journal of Dairy Science. 9// 2015;98(9):5905-16.
3) Ying D, et al. Effect of encapsulant matrix on stability of microencapsulated probiotics. Journal of Functional Foods. 8// 2016;25:447-58.
4) Tripathi MK, Giri SK. Probiotic functional foods: Survival of probiotics during processing and storage. Journal of Functional Foods. 7// 2014;9:225-41.
5) Roueche E, et al. Influence of temperature on the compaction of an organic powder and the mechanical strength of tablets. Powder Technol. 2006;162(2):138–44.
6) Possemiers S,et al. Bacteria and chocolate: a successful combination for probiotic delivery. Int J Food Microbiol. 2010;141(1–2):97–103.
7) Govender M, et al. A Review of the Advancements in Probiotic Delivery: Conventional vs. Non-conventional Formulations for Intestinal Flora Supplementation. AAPS PharmSciTech. 2014 Feb; 15(1): 29–43.