Authors: Abigail Mornement; Rachael Dack; Rebecca Clark
Affiliation: Department of Biosciences, Durham University, UK
Keywords: c. nutrition; m. microbiome
Unintentional weight loss is a common characteristic of ageing and frailty. While this may be partially explained by dietary changes and the metabolic cost of immune activation and inflammation that occur with age, other factors must contribute.
Nutrient absorption is a key role of the intestine which has not been studied in the context of ageing. Given the myriad changes occurring with age in the intestine, from increased bacterial load, to dysplasia and loss of intestinal barrier integrity, we feel that nutrient absorption is a likely contributing factor to this unintentional weight loss.
We have developed an assay to assess changes in the nutrient absorption/excretion profile in response to variables such as age or microbiota composition. Through this, we have found that more nutrients are egested with age, indicating a reduced absorptive capacity which may contribute to the unintentional weight loss observed with ageing and frailty. We are investigating changes in transporter expression with age as a possible mechanism. Additionally, by comparing the profile from axenic and conventionally reared flies, our assay confirms that the microbiota is a large source of protein and suggests that the microbiota further reduces the absorptive capacity of Drosophila. Thus potentially implicating the microbiome in age-related weight loss.