You’ve probably heard of probiotics. You may have even heard of the gut microbiome – the collective term for the billions of good and bad bacteria, fungi and viruses we each carry inside our stomach. The two are linked.
Probiotics is the name for a group of microorganisms that, as the International Olympic Committee (IOC) has stated, “when administered orally for several weeks can increase the numbers of beneficial bacteria in the gut.” The gut produces its own probiotics, but not always enough.
Science reveals the gut microbiome is involved in many bodily functions from gut and brain health to immune function and nutrient absorption.
As the research behind 100s of different probiotic strains has built over the decades – a search for ‘probiotics + human’ returns more than 15,000 papers on PubMed; over 40 for ‘probiotics + endurance’ – the little healthy bacteria have come to fortify foods as diverse as spoonable and drinkable yoghurts, juices, infant formulas, gummy bears, bars and breads not to mention food supplements and pharmaceuticals.
Certain probiotic bacterium can also be found naturally in fermented foods like cheese, yoghurt, kombucha, kefir and kimchi.
So probiotics can benefit the gut microbiome but can they play a role in sports nutrition? Can they improve your training, performance or recovery on the road, track, trail or in the water? Can they help prevent sickness and injury?
Naming rights: Choose clearly labelled probiotic products
According to the International Society of Sports Nutrition (ISSN) in a lengthy position paper published at the end of 2019 in its eponymous research journal the answer is ‘yes’. But it called for more research and noted the overall research base provides only ‘modest evidence’.
What it made clear though was that the best results come from using the right strains at the right doses. ISSN said the research review that formed the basis of its position paper was complicated “by variations in clinical outcome measures and most importantly, as probiotic benefits are strain-specific, by different strains used in these studies.”
Dr Ralf Jaeger, lead author of the ISSN position paper and managing member of Wisconsin-based nutrition R&D consultancy, Increnovo, told The Draft athletes should look for products that detailed their probiotic strain specifics.
“Probiotics have a first, middle and last name; a genus, species and strain identifying name. E.g. Lactobacillus (genus) acidophilus (species) LA02 (strain),” he said. “There can be up to 30% genetic variation between probiotics of the same genus and species. If a brand doesn’t disclose the strain, or the individual amount per strain, don’t use the product.”
Dr Jaeger recommended at least two weeks of supplementation to positive microbiome-altering results, noting that three weeks after you stop taking probiotics, “your microbiota resets to its original content.”
“Probiotics are transient, meaning they do not colonise for good, however, as long as they are there, they do their magic.”
Probiotic health benefits
ISSN found “certain probiotics strains can increase absorption of key nutrients such as amino acids from protein, and affect the pharmacology and physiological properties of multiple food components.”
It said probiotics had potential to combat ‘leaky gut’ which affects many sporting folk..
“Intense, prolonged exercise, especially in the heat, has been shown to increase gut permeability which potentially can result in systemic toxemia. Specific probiotic strains can improve the integrity of the gut-barrier function in athletes.”
ISSN pinpointed other potential athletic benefits from probiotic use including:
- improved body composition and lean body mass
- normalising age-related declines in testosterone levels
- reductions in cortisol levels indicating improved responses to a physical or mental stressor
- reduction of exercise-induced lactate
- increased neurotransmitter synthesis, cognition and mood.
The most potent sports nutrition probiotics
ISSN even went so far as to name the most effective strains after its scan of the available scientific lit. It found:
- Bifidobacterium coagulans GBI-30, 6086 (BC30) can benefit exercise recovery when combined with protein;
- Encapsulated B. breve BR03 in combination with Streptococcus thermophilus FP4 can benefit exercise recovery and performance following muscle-damaging exercise;
- Lactobacillus delbrueckii ssp. bulgaricus can increase VO2max and aerobic power;
- L. acidophilus SPP, L. delbrueckii bulgaricus, B. bifidum, and S. salivarus thermophilus administered in form of a yoghurt drink can increase VO2max;
- L. plantarum TWK10 can increase endurance;
- L. acidophilus, L. rhamnosus, L. casei, L. plantarum, L. fermentum, B. lactis, B. breve, B. bifidum and S. thermophilus can increase run time to fatigue in not weather.
Probiotic dosage – more is not always more
Probiotics’ well-documented ability to support immune and gut function and promote nutrient absorption are also very relevant to athletes who frequently put their bodies under extreme duress.
“Athletes may decide to take probiotics, to reduce the risk of upper respiratory tract infections or reduce gastrointestinal symptoms,” Kristina Campbell, author of The Well-Fed Microbiome told us.
Campbell said products that boasted the most voluminous probiotic count – known as Colony Forming Units (CFU) and typically ranging from 1-10 billion+ – were not always the most efficacious.
“For all probiotics, the dose you take should match what has been shown to be effective in clinical trials. Since the gut is a complex ecosystem that includes many kinds of bacteria co-existing and interacting, it’s not always about bombarding the gut with the highest possible CFU number. Sometimes less of the correct strain is more.”
Navigating a claimless landscape
The European Union’s strict health claims regulations means probiotic products are unable to make health claims on-product – Brexit may offer a looser claim-making arrangement in the UK in the coming years – leaving athletes to research benefits of their own accord. The EU has determined that even the term ‘probiotics’ is an unauthorised health claim and so products may employ a kind of reverse pseudonym where the vernacular name is replaced the technical name such as its probiotic genus, or something euphemistic like ‘healthy bacteria’ or ‘live cultures’.
Dragana Skokovic-Sunjic, clinical pharmacist at Hamilton Family Health Team in Canada and co-author of the Clinical Guide to Probiotic Products Canada/US, noted claim-making was less stringently controlled in North America.
“It is all done for the sake of the safety of the consumer but the EU seems to be doing a bit of a disservice as consumers are likely missing out on benefiting from probiotics when selected appropriately,” she relayed.
There’s that notion again: Choosing the right products. Do that and probiotics appear to have something to offer athletes.
As an aside, athletes have been found to have a more diverse microflora than sedentary types – basically it appears exercising (plus good diet) improves the gut microbiome by increasing microbiota diversity and going some way to explaining why exercise is so good for most people’s overall wellbeing.
*It should be noted that the way many probiotic strains are officially named and classified underwent a major overhaul last month. However, it will be some time before the changes filter through to product claims and labelling.