Effect of a Short-term Multi-strain Probiotic Supplementation in Endurance Athletes

Inclusion Criteria: * belonging to the national rowing team; * training experience ≥5 years; * a currently issued medical certificate confirming * good health and capacity to practice sports; * good health without chronic health disorders; * written informed consent to participate. Exclusion Criteria: * injury, any health contraindication or failure to perform exercise procedures; * gastrointestinal infections, diseases, disorders; * past history of gastrointestinal surgery, and * other self-reported gastrointestinal issues; * reporting symptoms of infection or taking any medication (e.g. antibiotics) for 4 weeks before the study protocol; * current supplementation of prebiotics, * probiotics, synbiotics (last 4 weeks); * current intake of pharmaceutical agents (e.g., nonsteroidal anti-inflammatory drugs, laxatives, antidiarrhea agents, antacids, and/or antiemetics) (last 4 weeks); * failure to follow the study protocol; * declared general feeling of being unwell; * pregnancy or current pregnancy planning.