Probiotics are not termed or classified as a medication which means that the FDA regulation is there with all the foods that are known or advertised as probiotics. This basically means that the companies producing probiotics do not need to advertise or market their products to consumers as safe. Even their efficacy is not to be labeled or advertised. In most cases these products are considered safe for usage however for individuals with serious health conditions, chronic illnesses or other unusual medical condition it is safest not to use the probiotics without strict consultation with their health care professional.
For those who are considering taking probiotics, they should know that even with the best probiotic there are mild side effects which could be caused due to their usage such as having a bloated stomach, having gas or getting diarrhea. These symptoms are usually mild and should only last for the first few days, however if the symptoms are prolonged, you must stop using the probiotics immediately and consult your physician immediately.
So how safe are probiotics? Well, humans have consumed good bacteria via different foods such as yoghurt, cheese and other dairy products for generations. However nowadays, a wide variety of these bacteria or live organisms are added to different products for our consumption which are advertised to treat a wide variety of stomach ailments and digestive issues as well as providing other health benefits to patients suffering from common colds, skin related problems, cardiovascular issues or respiratory concerns. However, the research done thus far, does not strongly support any claims of vast health improvements in the consumers of these probiotics. So while the lesser volatile issues such as irritating bowel or diarrhea do get treated well with these products, their long term benefits as advertised remain yet to be clinically proven.