CFU stands for 'colony-forming units', which refers to the number of live and active microorganisms that you can expect in a probiotic supplement. This is determined in the laboratory, and CFU tells us the viability and number of microorganisms in the probiotic prior to exposure to the gastrointestinal tract. The active microorganisms tend to live and grow together as colonies, even though we sometimes refer to them as individual bacterial strains. CFU essentially refers to the beneficial bacteria that you can expect, as a total count per dose.

The number of CFUs is one important factor to consider when taking a probiotic, but it's not the only factor. Probiotics are expensive to manufacture, so a higher CFU can often be a good indication of quality or whether a probiotic is value for money or not, however, it doesn't necessarily mean it has better efficacy or outcomes. Likewise, a low CFU count may (or may not) be adequate for your particular health goal. Most probiotic supplements have a range between 1-20 billion CFUs of live bacteria per dose, while there are some that have 50 billion or more, and there are others with 100 billion and more

Combinations of probiotic strains have had robust research for a number of different purposes. The human body’s microbiome contains over 800 different bacterial species, so it is inherently diverse and naturally a multi-strain, multi-species environment. It is therefore generally believed that we need to help repopulate the microbiome with a combination of strains to complement our natural flora, rather than one specific strain.

The vast majority of clinical studies have shown that probiotics exert beneficial effects on gut health issues ranging from IBS, bloating and gas, to acid reflux and constipation. But we also know that by restoring the intestinal balance of harmful microbes with healthy bacteria, the beneficial effects experienced reach far beyond gut health. There are bi-directional relationships that exist between the gut and other organs that have been referred to as the gut-brain axis, the gut-skin axis or the gut-vagina axis, for instance. The gut also plays a vital role in regulating our hormones and many other health issues.

The short answer to this question is YES. Prebiotics are plant fibres that are not digested by your body, which means they travel through your stomach to your digestive tract, where they feed and support the probiotics in your gut. When probiotics feed off prebiotics, they produce lactic acid and short-chain fatty acids that improve the digestion of foods and the overall health of your gut microbiome. Put simply, without prebiotics, probiotics are not nearly as effective.

Postbiotics are considered to be the compounds created by bacteria during the fermentation process. They are the beneficial end products of bacteria. Unlike prebiotics, postbiotics do not contain live microorganisms; however, they can still be effective in their own right. Postbiotics can contain nutrients like Vitamins B and K, as well as substances that slow down the growth of unhealthy bacteria.

Whether you need a probiotic or not is up to the individual, their circumstances, their health status and the health concerns they are seeking to improve. Generally, healthy people might just want to take a probiotic daily to keep their immune system in check, support their gut health when travelling and eating new cuisines or improve their skin condition.