Dr Megan Rossi (@Theguthealthdoc on Twitter) is a registered dietitian who has a PHD in gut health
How does cycling affect the gut?
During strenuous exercise, blood moves away from the gut, so it doesn’t get the oxygen it needs. In extreme cases such as in ultra-endurance athletes, this can lead to ischaemia, where the gut cells start to die. Even in less extreme exercise, there is some damage to the gut.
There seems to be a disparity between official guidelines and research surrounding leaky gut, where certain substances leak through into the bloodstream? Leaky gut is quite a new area, and because it’s a consequence of something else — e.g. stressors — it’s not something we can directly treat. We treat it by removing the stressors and knowing that if you do, for example, extreme exercise, you’re going to have these gut consequences. It’s important not to get too hung up on it because we know exercise is overall beneficial. We also know our body can adapt. If you build training up slowly, your gut will adapt too.
What are your thoughts on probiotics?
As yet, nothing very promising has come of research into whether probiotics enhance performance. However, I think it’s an important area and there are a lot of mechanisms by which they could improve performance, from immune function, to reducing leaky gut and systemic inflammation caused by exercise. There isn’t a lot of evidence in support of supplements at the moment. I recommend focusing on maximising your gut health through lifestyle means.