Diet and muscle function during ageing

Mitochondrial dysfunction, changes in the non-contractile structure within muscle and alteration in protein synthesis efficiency result in age related muscle mass loss. Current work with Southampton University (Prof. Paul Little) has assembled a biobank of over 1000 patients who have been identified as being at risk of malnutrition via primary care. The application of metabolomic profiling to this population, would enable a researcher to understand the mechanistic relationship between decline nutritional status and loss of physical functional capacity. A second bio-bank of samples have been collected from clinical patients who are at risk of post-operative complications due to poor nutritional status and sarcopenia. The work already carried out by Aberystwyth University (Dr Thomas Wilson) and Cardiff University (Dr Jonathan Hewitt) has shown that urine sampling is feasible in patients undergoing surgical treatment for colorectal cancer. The use of metabolomics technology to objectively stratify a patient’s risk status, prior to surgery would be a key deliverable of this new metabolomics platform. These studies would benefit greatly from use of a dietary exposure biomarker panel based on LC-MS/MS to produce objective information on eating behaviour and a high-throughput metabolomics platform to stratify populations appropriately and to filter out signals associated with unreported behaviours such as pharmaceutical intake to help counteract the main drivers of confounding variability in our study populations and older individuals. 

Similarly, dietary exposure to protein-rich foods is difficult to estimate with increasing consumption of processed foods in the UK and protein under-consumption is emerging as a significant risk in an aging population. As part of the UK Metabolic Phenotyping Consortium (MAP/UK), the Diet and Health Research Group are focusing on analytical methodology to specifically measure protein intake, amino acid utilisation and endogenous catabolism of dietary protein. These methods would allow for high throughput screening of at-risk individuals, prior to any phenotypic presentation of muscle loss and impaired physical function.