Gut-muscle axis interventions for ageing consumers: experts discuss strong emerging evidence

This was the key outcome from a panel discussion at the Active Nutrition Summit in Amsterdam this week (9 – 11 Oct).

Gut-muscle axis​

Dr. Justin Roberts, associate professor and senior team lead at Danone Nutrition Research, highlighted the importance of continued exercise with age and the progressing gut-muscle axis research.

He explained: “We’re looking at how metabolites from the gut may or may not impact the muscles. There’s strong animal evidence reinforcing this idea of the gut-muscle axis, whilst there’s strong emerging evidence of this in humans too.

“We know that if there’s a diversity of certain bacterial species in the gut, there is a direct impact on frailty. Also, highly frail populations may have a lower gut diversity or lower quantities of certain species. What we don’t know is how the gut-muscle axis would be impacted in those with existing sarcopenia who are given prebiotics or probiotics to target this.”

Dr. Andy Franklyn-Miller, chief medical and innovation officer at Nuritas, agreed on the data gaps, explaining: “There are significant challenges in investigating this in terms of the presence of comorbidities. If you exclude the patients with no history of inflammatory or cardiovascular disease etc., it’s a totally artificial environment and this would be a very small subset.

“If you look at the epigenome of the microbiome in that population, this could give us incredibly inaccurate data. The real-life studies are very hard to do because of the heterogeneity of the population. We have to accept that the science isn’t possible in terms of an RCT for this,” he added.

Roberts explained the evidence on athletes’ microbiomes: “Their microbiome composition depends on the type of sport, whether its endurance, aerobic, strength etc. We know that athletes produce more SCFAs than controls and this can have a potentially protective effect on the training.

“So if you have more cytokine proinflammatory cascades because of the training, how will this effect performance? And if we can increase SCFA production in someone who is not training, through fibre or other means, will this have a protective effect when they then train? That’s the next step,” he asserted.

Nutritional interventions​

Roberts described the potential for creatine within the ageing population: “A meta-analysis looked into the effect of creatine whilst ruling out the effect of other supplements, and it found a potent effect on increasing muscle mass by around 1.4kg, which is significant.

“In older people, it may be that the maintenance phase of creatine intakes needs to be higher. In those not resistance training, it may be that they need a loading phase too.”

Jane Durga, nutrition science consultant at Balchem, spotlighted the additional efficacy of mineral additions: “Magnesium and creatine interlock in relation to ATP synthesis. Balchem has created a blend of the two called ‘Magnepower’, which may actually increase the bioavailability of creatine.”

She added the importance of sulphur for protein synthesis, with intakes mainly obtained through amino acid dietary sources.

“Vegetarians and vegans may have limited sulphur intakes, so there’s a substantial population who may not be having enough. When you’re in an environment of limited sulphur, it is salvaged for protein synthesis at the expense of hundreds of other compounds that need to be synthesised, such as glutathione for antioxidant activities.

“So sulphur is a good ingredient to watch and the awareness will increase. Most people don’t think of sulphur as a good option to add on to their supplement regimen for increasing their performance or recovery,” she added.

Targeted pathways​

Regarding the influence of age-related inflammation, Roberts discussed effective nutritional interventions to reduce this and enhance performance.

He explained: “There’s a number of natural foods that have a variety of compounds, from phenolic compounds to flavonoids. such as bilberries, blueberries, and green tea, that all have anti-inflammatory properties. The one that seems most convincing are omegas.”

Franklyn-Miller spotlighted current interest in mitochondrial-targeted interventions, explaining that current research has suggested that targeted ATP generation may help in terms of neuro-cognitive function.

Yet he highlighted the challenges in researching at this level: “One of the real problems we have is that we have to break down the biological pathways into individual components, which is what’s happening in the NAD space.

“With mitochondrial biogenesis, the biohacker’s dream would be to at-will selectively up and downregulate this process. But the control pathways there are so complex. You can drive a pathway from one step in the process, but the challenge is knowing the up and downstream consequences of that, which currently limits overall effectiveness,” he added.

Roberts agreed on the complexities, adding: “For me personally, it’s interesting to look at the two key pathways on top of NAD. So, looking at single and combination nutrients that target both those two pathways, that’s where it starts to get interesting.”

He added that he felt it was important to target younger generations for future interventions to prevent these irreversible age-related diseases in later life.