Abstract
Experiments involving food restriction are common practice in metabolic research. Under fasted conditions, mice supplement their diet with cage bedding. We aimed at identifying metabolic and microbiota-related parameters affected by the bedding type. We exposed mice housed with wooden, cellulose, or corncob cage beddings to ad libitum feeding, caloric restriction (CR), or over-night (ON) fasting. Additionally, two subgroups of the ON fast group were kept without any bedding or on a metal grid preventing coprophagy. Mice under CR supplemented their diet substantially with bedding; however, the amount varied depending on the kind of bedding. Bedding-related changes in body weight loss, fat loss, cecum size, stomach weight, fecal output, blood ghrelin levels as well as a response to glucose oral tolerance test were recorded. As fiber is fermented by the gut bacteria, the type of bedding affects gut bacteria and fecal metabolites composition of CR mice. CR wood and cellulose groups showed distinct cecal metabolite and microbiome profiles when compared to the CR corncob group. While all ad libitum fed animal groups share similar profiles. We show that restriction-related additional intake of bedding-derived fiber modulates multiple physiological parameters. Therefore, the previous rodent studies on CR, report the combined effect of CR and increased fiber consumption.
Highlights
Experiments involving food restriction are common practice in metabolic research
With similar starting bodyweight (Supplementary Fig. S1), overnight-fasted mice from ON-W, ON-C, ON-CC, ON-NB groups lost 13–14% body weight (Fig. 1b) while ON-G mice lost 16% body weight suggesting the impact of coprophagy and/or cage bedding consumption on body weight
caloric restriction (CR) mice had less epididymal white adipose tissue (Supplementary Fig. S1) and subcutaneous white adipose tissue (Supplementary Fig. S1) than control groups, there was no impact of the bedding type
Summary
Experiments involving food restriction are common practice in metabolic research. Under fasted conditions, mice supplement their diet with cage bedding. We exposed mice housed with wooden, cellulose, or corncob cage beddings to ad libitum feeding, caloric restriction (CR), or over-night (ON) fasting. In animal as well as in human studies CR has been shown to increase lifespan and health-span It prevents the development of various diseases including age-related, neurological, and metabolic diseases as well as cancer[3,4]. Bedding consumption is important in the context of the rapidly developing field of gut microbiota Dietary fibers, including those present in cage bedding, may undergo complete or partial fermentation by the gut m icrobes[15], leading to the production of short-chain fatty acids (SCFA) and stimulating the growth of certain bacterial species[16]. We aim at studying the variability in research outcomes introduced by cage beddings as well as bringing awareness to the reproducibility of the studies involving fasting and CR by stressing the importance of bedding
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
