Supplementary materials to Beneficial Microbes: <b>Ageing and the gut-brain axis: lessons from the </b><b><i>Drosophila</i></b><b> model</b>

<p dir="ltr">The steady decline of physiological function and increased vulnerability to age-related disorders are two features of the complicated biological process of ageing. As a key organ for nutrient absorption, metabolism, and immunological regulation, the gut plays a major part in the ageing process. <i>Drosophila</i> <i>melanogaster</i>, a well-established model organism, has emerged as a significant tool for exploring the intricate rapport between the gut and ageing. Through the use of <i>Drosophila</i> models, the physiological and molecular elements of the gut-brain axis have been thoroughly explored. These models have also provided insights into the mechanisms by which gut health impacts ageing and age-related illnesses. <i>Drosophila</i>'s gut microbiota experience dysbiosis with age which has been linked to age-related diseases. To prevent this and promote healthy ageing in <i>Drosophila</i>, gut microbiota modification methods, such as dietary restriction in tandem with time-restricted feeding, administration of pro-, pre- and synbiotics, as well as pharmaceutical interventions have been generated with positive impacts. The article also covers the drawbacks and difficulties of investigating the gut via the <i>Drosophila</i>. Thus, with an emphasis on the lessons discovered from <i>Drosophila</i> research, this review provides an extensive description of the current studies on the role of the gut-brain axis in ageing and health.</p>