Hello BillPopMMS, I believe that probiotics are helpful, and worth the money, when there's an issue with insufficient gut bacteria and a problem with digestion, for example when using antibiotics and other gut bacteria killers. There are certain food products stimulating the health and growth of gut bacteria. The following text is copied from the Mayo Clinic website:
"PREBIOTICS
Prebiotics are specialized plant fibers. They act like fertilizers that stimulate the growth of healthy bacteria in the gut. Prebiotics are found in many fruits and vegetables, especially those that contain complex carbohydrates, such as fiber and resistant starch. These carbs aren't digestible by your body, so they pass through the digestive system to become food for the bacteria and other microbes.
PROBIOTICS
Probiotics are different in that they contain live organisms, usually specific strains of bacteria that directly add to the population of healthy microbes in your gut. Like prebiotics, you can take probiotics through both food and supplements. Probably the most common probiotic food is yogurt. Yogurt is made by fermenting milk with different bacteria, which are left in the final product. Other bacteria-fermented foods, such as sauerkraut, kombucha and kimchi, are also good sources of probiotics.
SUPPLEMENTS
One thing to understand about supplements is that there are many, many kinds. For instance, one type of bacteria commonly used is lactobacillus. But there are more than 120 species of lactobacillus, and at least a dozen of them are used as probiotics.
What's more, there are several other types of bacteria, each with dozens of species, making for a dizzying variety of available probiotics. And even when you select a kind of bacteria, the amount in the supplement can vary between brands. When taking a probiotic, research the condition you wish to address and select the probiotic based on that condition".
Natural supplements are obviously most wholesome. Brands may show differences in quantity of ingredients and composition. I myself rely on prebiotics and probiotics present in my daily food substances, if only for the far lower costs compared to pills etc.