When seeking out the best probiotic for you, consider your overall health, dietary needs, antibiotic use, GI challenges, and similar concerns. Then, review our list of the ten best probiotic supplements, which offer everything from raw probiotics, which must be refrigerated, to shelf-stable, slow-release probiotics that concentrate fewer CFUs in tiny, once-daily capsules.

Our gut is home to over 500 bacterial species. These “visitors” form a bioreactor, which facilitates digestion, provides nutrients, and helps form the immune system. Some important nutrients made by this bioreactor include several B vitamins, vitamin K, folate, and some short-chain fatty acids. Up to 10% of an individual’s daily energy needs can be derived from the byproducts of the good bacteria in your gut.
Although some probiotics have shown promise in research studies, strong scientific evidence to support specific uses of probiotics for most health conditions is lacking. The U.S. Food and Drug Administration (FDA) has not approved any probiotics for preventing or treating any health problem. Some experts have cautioned that the rapid growth in marketing and use of probiotics may have outpaced scientific research for many of their proposed uses and benefits.
"Contrary to the current dogma that probiotics are harmless and benefit everyone, these results reveal a new potential adverse side effect of probiotic use with antibiotics that might even bring long-term consequences," Elinav said in a statement. "In contrast, replenishing the gut with one's own microbes is a personalized mother-nature-designed treatment that led to a full reversal of the antibiotics' effects." Segal added, "This opens the door to diagnostics that would take us from an empiric universal consumption of probiotics, which appears useless in many cases, to one that is tailored to the individual and can be prescribed to different individuals based on their baseline features."
BlueBiotics is a good product to start with and then evaluate from there. The cold is actually good for probiotics as freezing them extends the life of the cultures. Companies who freeze dry their probiotics (which if I’m not mistaken, each of these companies do), but having them shipped in very high temperatures can and does kill probiotic microorganisms so it’s definitely a concern. Ideally, it’s better to stock up during the winter so that you don’t have your product stuck in the back of a hot truck before it gets to you.

Probiotics contain 'good' bacteria, and that's exactly why we need them; because it's not just 'good' bacteria calling our gut home. Taking a probiotic supplement (along with a healthy diet) increases the number of good bacteria, reduces the number of bad bacteria and creates an environment that’s suitable for beneficial microorganisms, which improves our overall health.

For most of my life, I thought of probiotics as something I’d only drink if I lost a bet. Then stress-induced irritable bowel syndrome (IBS) turned my intestinal tract into a nonstop river of shit—we’re talking weeks of everything I ate shooting straight out my butt in liquid form. The internet said probiotics were my best non-pharmaceutical bet to help my digestive system calm down, so I swallowed my pride (and my first kombucha ever) and kinda sorta saw the light. My IBS wasn’t cured, but probiotics did help me spend less time on the toilet wide-eyed with terror, and more time doing what’s really important in life—watching TV with my family.
The first major finding was that many people were essentially resistant to any effect from probiotics and their gut microbiome did not change after taking them.  Of 19 people in the study taking probiotics consisting of 11 of the most commonly found strains, only 8 had any notable colonization of their gut with the bacteria in the probiotics, with 3 people considered to have significant colonization and 5 people with "mild" colonization.
Also, it’s important to understand that probiotics are not a new idea. Throughout history, cultures have thrived on probiotics found in fermented foods and cultured foods, which were invented for food preservation long before the refrigerator. The process of fermentation has been lost in recent years, as it is no longer needed to preserve foods, meaning that we now lose out on those vital probiotics benefits. 

In the new study, the researchers analyzed information from 15 healthy volunteers who took either a probiotic product containing 11 strains of bacteria, or a placebo, for four weeks. The participants also underwent colonoscopies and upper endoscopies before they took the probiotics or the placebo, and again after the four-week treatment period. (An upper endoscopy looks at the upper part of the digestive tract.) During these procedures, the researchers took samples from inside participants' guts.

Another study by Elinav and his colleagues suggests that not everyone’s gut reacts the same way to probiotic pills. They studied samples of microbiomes from antibiotic users before and after they took supplements for four weeks. The good bacteria were found in the digestive tracts of some people. But in others, the bacteria were present only in stool samples, not in their digestive tracts, where they’re thought to be needed to improve health.

Update: I think this product is being smeared by a competitor! Look at all the reviews in April. Suddenly, a butt ton of not just negative but 1 star reviews. It's uncanny. So, what would compel a competitor to do such a thing? Well, it was the only 50 CFU, enteric coated & 20 strain probiotic on Amazon & it cost about 15 bucks. That, while products far inferior to it were priced for - often times - 2 or 3x as much.
You also want to look at the guarantee fine print: If the CFU number is guaranteed at time of manufacturing, but not at the time of expiration, you could be taking a less potent dose of probiotics than you think because potency fades over time. I made this mistake when I was traveling once and went to the grocery store to pick up probiotics. On the bottle label it said guaranteed at 20 billion CFU at the time of manufacturing. This doesn’t tell you the CFU for when I was actually taking the probiotics. For instance, our probiotics are manufactured at 60 billion and 200 billion CFU, and guaranteed at 30 billion and 100 billion CFU, respectively, at time of expiration.
This dairy-free, gluten-free, vegetarian probiotic delivers live microorganisms, protected in stomach acid-resistant capsules to ensure effective delivery throughout your digestive system, from the stomach through your small intestines. The result is the repair and sustained maintenance of your intestinal micro-ecology, which in turn helps support healthy immune response and bowel regularity.
How can something as small as a microscopic organism be so important for health? The reason is that there is not just one microbe, nor a handful; there are approximately 1 trillion microbes per gram of feces. Microbes within you are found on your mucous membranes, spanning from your mouth to your anus, from your nasal passages to your lungs, in your urinary tract, and even on your eyes. In fact, in your digestive tract alone, it is calculated that for every cell of yours that is human, there are an equal number of bacterial cells.
Jotham Suez, Niv Zmora, Gili Zilberman-Schapira, Uria Mor, Mally Dori-Bachash, Stavros Bashiardes, Maya Zur, Dana Regev-Lehavi, Rotem Ben-Zeev Brik, Sara Federici, Max Horn, Yotam Cohen, Andreas E. Moor, David Zeevi, Tal Korem, Eran Kotler, Alon Harmelin, Shalev Itzkovitz, Nitsan Maharshak, Oren Shibolet, Meirav Pevsner-Fischer, Hagit Shapiro, Itai Sharon, Zamir Halpern, Eran Segal, Eran Elinav. "Post-Antibiotic Gut Mucosal Microbiome Reconstitution Is Impaired by Probiotics and Improved by Autologous FMT." Cell (First published: September 6, 2018)  DOI: 10.1016/j.cell.2018.08.047