The gut remains an essential part of our wellbeing, with a huge amount of on-going research attempting to further understand this complex microbiome. The gut is home to two-thirds of our immune system; it’s the biggest line of defence against the outside world (aside from the skin), essential for transport of nutrients, protection against pathogens and our immune response. It’s also known as the ‘second brain’ – our ‘gut feeling’. It’s home to the largest amount of nerve endings outside of the central nervous system and where most of our body’s ‘happy’ neurotransmitter serotonin is made.
The gut is home to more than 1 trillion gut bacteria – more cells than the cells of the human body. Tight junctions between our gut barrier cells are essential and disruption leads to intestinal
hyper-permeability, often known as “leaky gut”. Substances that can increase intestinal permeability include the consumption of alcohol, spices, NSAIDs. Symptoms can include allergies, systemic inflammatory response, IBD, IBS and coeliac disease.
Gastro-intestinal (GI) issues affects 30-50% of athletes, especially endurance athletes and is often overlooked in nutritional programmes (1). It can range from acute increased GI motility to longer term chronic conditions linked to on-going GI stress such as IBS and IBD. Symptoms and severity vary greater amongst athletes. 70-93% of elite trained athletes suffer with mild to moderate symptoms such as nausea, discomfort, cramping, urgency, diarrhoea, vomiting. Distance is often a key issue – 4% marathon runners and cyclists, verses 32% Ironman. Severe symptoms can include ischemic bowel, colitis, gastritis, lower GI bleeding (2).
There are many different reasons, physiological and mechanical, that can cause these issues in athletes, especially runners. Reduced GI blood flow, dehydration, increases in body temperature, gut permeability or H.Pylori (bacterial infection of the stomach) can often be issues. Mechanical symptoms are more common in runners due to the repetitive GI impact, where as cyclists endure increased pressure on the GI tract. Gut mucosal lining is often challenged by irritants (such as running or cycling on a busy road), excess secretion of stomach acid and pepsin (lots of dairy and meat require higher amounts of stomach acid to digest them). Low stomach acid (often caused by not being able to deal with high animal protein or dairy!) can also cause bacterial infection such H Pylori. Alcohol increases those T-junctions in the gut, allowing irritants to get into the blood stream (often causing sneezing and increases in histamine after drinking). Stress is often a cause – this word was only ever used as an engineering term up until the 1950s! Now it’s so omnipresent in our day to day life, added to the exercise stress/trauma the body deals with during intense training.
Inflammation is a constant problem for many athletes. NSAID consumption can increase stomach lining problems and affect gut motility, inflammatory responses also put our immune system on hyper-drive, which is where food intolerances can start to manifest – ideally 99% of the time we don’t want our immune system to be working! Switching to a plant based diet has been hugely beneficial for endurance athletes such as Scott Jurek and footballer Jermain Defoe. Plant based nutrition is naturally anti-inflammatory where as animal products such as meat and dairy contain pro-inflammatory properties which can exacerbate injuries and recovery. Plants are also easier to digest and epidemiological evidence confirms a strong association between dietary fibre and reduced all-cause mortality risk (3), beneficial for everyone.
See your gut as an athletic organ! It can be nutritionally trained to deal with the pressures of endurance training. As a nutritional therapist we work with the individual so interventions are tailor made dependent on the needs of our clients. The starting point is helping to support microbiota diversity in the gut and creating the right environment in the gut for beneficial bacteria to grow including probiotic supplements and plant fibre. There is increasing research into the benefits of probiotics to support gut immune response (4,5). L-glutamine has been shown to the be principle fuel and nitrogen source for cells in the gut, helping to reduce gut inflammation. Antioxidants are also key. Sourcing from brightly coloured fruits and vegetables (including white and green) is always recommend over supplements as they are all in their synergistic and easy to digest. Allicin in garlic helps to defend against bacterial and fungal species including Salmonella, H. pylori, Streptococcus, Vibrio and Candida albicans too.
You’re 99% microbe…its time you started eating like it –Jeff Leach
Foods to minimise and optimise prior to training:
- Total sugar load – refined sugar and simple carbohydrates.
- Caffeine can cause gut spasms as can dairy and wheat.
- Reduce dairy and gluten.
- Excessive stress
- Sources of prebiotics (which help create the right environment for healthy bacteria to grow): Jerusalem artichokes, chicory, asparagus, leeks, fermented foods such as kefir, sauerkraut, kimchi.
- Increase anti-inflammatory foods: linseed/flaxseed oil and seeds, oily fish (salmon, trout, sardines, mackerel), ginger, turmeric, garlic.
- Antioxidants from brightly coloured vegetables and fruits. Berries and cherries – sources of bioflavonoids which can help to repair the gut lining.
- An apple a day – will keep the doctor away by helping to nourish your gut – apples contain pectin which helps to keep bowel movements regular.
- All vegetables help to provide gentle soluble fibre which provides the right environment for beneficial bacteria to grow. Beetroot, carrots, mango, peppers, spinach, sweet potato – sources of beta-carotene which help support the immune system.
- Peppermint tea – helps to increase digestive secretions is known to be calming and to help reduce gut spasms.
- Ground linseed (flaxseed) – help to nourish the gut as it turn into a mucilage. Add to smoothies or low sugar granola or porridge to help nourish the gut. Also a good source of protein. Psyllium husk as a similar affect in the gut – bulking agent and a great source of gentle fibre.
- Maintain hydration during training
- NO stimulation (nitrates)
- Probiotics– high potency ones.
- Zinc (citrate form the best absorbed by the body)
I created the Sport Elixir as a vegan protein post training recovery blend. There’s a lot of mis-information out there about how much protein you should take after training. Do you really need to have 20g of protein after training for an hour? My approach is to take it from food as opposed to flavoured whey protein powders or highly sweetened protein bars. My issue with all the whey protein is that it can be very hard to digest, causing symptoms such as bloating, and it’s also pro-inflammatory. Inflammation is the scourge of every athlete and it’s important to keep it in check which is why I prefer to use vegan plant protein. Plant protein is also a natural source of fibre which nourishes the gut and helps create the right environment in the gut for beneficial bacteria to grow. Vitamin C is also essential to help support the immune system after training – if your immune system is sluggish then your performance is likely to be too. Our Sport Elixir contains over 110% of our recommended daily allowance of Vit C in every 10g serving.