The World Health Organization defines probiotics as live microorganisms that confer a health benefit to the host when consumed in adequate amounts. The quality and effectiveness of each product depend, among other things, on the manufacturing processes, the strains and viability of dosed bacteria, and their ability to survive the physiological conditions within the gastrointestinal (GI) tract. There are no regulations governing the production of probiotics, also contributing to the differences in quality and efficacy. Regardless of the quality of the probiotics, the safety and efficacy can only be confirmed by adequate clinical studies.
Refrigerated probiotics generally contain a wider range of live bacterial strains and species at higher concentrations than non-refrigerated products. This allows to maintain the same proportions of the strains within the blend and can improve their effectiveness in colonising the gut and modulating the microbiome.
Traditionally, the goal has been to keep microorganisms alive until consumption. However, the viability of these bacteria depends upon many factors, such as manufacturing processes, competing bacteria, and toxicity of metabolites. Scarce scientific evidence currently suggests that once ingested, molecules and surface components secreted by bacteria are sufficient to mediate the cross-talk between the host and probiotic cells.
The International Scientific Association for Probiotics and Prebiotics have produced evidence-based recommendations on the safety of these products in different populations. The effectiveness of probiotics may vary depending on treatment, disease, and strains that make up the probiotic (1).
It is essential to choose a reputable probiotic supplement that matches the individual’s needs and follow the manufacturer’s instructions for storage and usage to maximise the benefit (2).