Consumers seem to think so and the marketplace abounds with new multi-strain probiotic formulas to meet the need. But what if anything does the research say about any added value?
The International Probiotics Association looked at the evidence in a recent blog Probiotic Supplements: Practical Tips.
Two excellent reviews are cited.
In Effectiveness of Multistrain Versus Single-strain Probiotics: Current Status and Recommendations for the Future by Dr. Arthur Ouwehand PhD and colleagues found “no strong evidence that the assumptions are incorrect and/or that there is antagonistic activity between strains in a combination.” One study suggested that there is at least no antagonistic activity between strains in multi-strain product.
The problem lies in total dose variations, too many strains in mixtures and lack of placebo in studies. In addition, multi-strains may have higher total colony forming units (CFUs),the number of viable bacteria or fungal cells in a sample.
In the second review by Dr. Lynn McFarland PhD titled Efficacy of Single-Strain Probiotics Versus Multi-Strain Mixtures: Systematic Review of Strain and Disease Specificity, randomized controlled trials from 1973 to 2019, in most cases, multi-strain mixtures were not significantly more effective than single-strain probiotics. More structured research is needed before clinicians can recommend multi-strain over single strain.
Most importantly, the included probiotic strain(s) must be beneficial for a targeted health condition based on clinical research.