Are there any concerns or considerations?

May cause GI side-effects

• Some individuals report mild symptoms of stomach rumbles, increased flatulence or changes in the stool during the first week of supplementation as the gut microflora changes to accommodate the newly introduced species. These symptoms may be reduced by a gradual introduction of the probiotic protocol, building up to the recommended dose over a week or two.
• Individuals with a prior history of gastrointestinal tract problems such as coeliac disease or irritable bowel syndrome may be at greater risk of side effects such as an upset stomach or bowel problems.

Some products may not provide sufficient numbers or types of probiotics

• Several studies have reported low viability for commercially-available probiotic formulations and supplements with insufficient numbers of species, and in some cases the presence of species different to those declared on the label.
• Individuals are advised to obtain probiotics through a reputable source such as a sports dietitian or their sporting organisation/program. Priority should be given to evidence-based probiotics that have been tested independently under controlled conditions.

Evidence for benefits is still lacking certainty

Benefits may be highly specific to certain individuals and scenarios of use. Although most studies report positive health effects in athletes and active individuals, there is still no substantial scientific evidence to suggest that probiotics play an important role in improving an athlete's performance. Further research is needed before definitive protocols can be established to identify the likely health and performance benefits, supplementation protocols around training, travel and competition, and interaction with other targeted dietary practices.