Effect of Probiotics on Endurance Athletes' Microbiome at Rest and Post-race

This study is intended to investigate the use of probiotics (LAB4 probiotics, Cultech, Port Talbot, Wales, UK) and the effect this has on gastrointestinal symptoms experienced during elite long-distance triathlon (ironman) competition, as well as the composition of the gut bacteria in the athlete.

Long-distance triathlon events frequently induce gastrointestinal discomfort due to the duration of the event (8-17 hours), the intensity of the exercise and the ingestion of large amounts of sugars throughout the event.

Data will be collected from athletes participating at the Kona ironman World-championships. Participants will supplement with either probiotic tablet, or placebo (sugar-pill) for 4-weeks prior to competition.

Athletes will be both male and female age-group athletes from any qualifying age category (age categories are as follows: 18-24; 25-29; 30-34; 35-39; 40-44; 45-49; 50-54; 55-59; 60-64; 65-69; 70-74; 75-79; 80-84).

The main investigation of the study will be the occurence/frequency/severity of gastrointestinal symptoms during training and competition between groups.

The study will recruit ironman triathletes who have qualified for the Kona ironman World-championships in Hawaii. Participants will be allocated into either probiotic (Lab4 Probiotics, Cultech, Port Talbot, Wales, UK) or placebo (Maltodextrin) groups, in a double-blind fashion (Blinded by supplement supplier).

Those recruited into the study will have their training load and gut symptoms monitored for 8-weeks prior to competition via the completion of online questionnaires (previously validated).

Four-weeks prior to competition participants will provide a stool sample for microbiome analysis, they will then proceed to supplement with probiotic or placebo for 4-weeks. 24-h prior to competition they will provide a stool sample as well as providing a sample from the first bowel movement post-race, which will be used for microbiome analysis.

Data will be collected for pre-race and raceday nutrition, as well as outcome measures for raceday performance and gastroitestinal symptoms experienced, again via online questionnaire.

Stool samples will be analysed by an independent laboratory that specialises in microbiome analysis.

Primary outcome measures will be the composition of the gut bacteria and the metabolites (substances produced) of the gut bacteria at baseline, pre-race and post-race. As well as the occurrence (frequency, duration, severity) of gastrointestinal symptoms during training and competition.

Eligibility Criteria:
Inclusion Criteria:

* Aged 18-85
* Qualification for the Kona Ironman World-championships in Hawaii

Exclusion Criteria:

* Have a current musculoskeletal injury.

  * Currently unwell with cold or flu
  * Have been told they have liver disease
  * Have gastric Ulcer or other gastric/stomach problems
  * Have a condition/disease of the Gut/bowel.
  * Have diagnosed uncontrolled asthma
  * Have kidney problems
  * Have a chronic connective tissue disorder
  * Have suffered cerebrovascular disease such as a stroke
  * Are taking balcofen, methotrexate, tacrolimus and voriconazole, beta-blockers or diuretics drugs