The Effects of Severe Food Restriction and Post-Recovery on the Gut Microbiome

Intestinal bacteria live in a complex environment and play an essential role in nutrition and energy expenditure1. With approximately 100 trillion gut microbes representing as many as 5,000 species2, the human gut microbiome plays a crucial role in human health and is strongly controlled by dietary factors. Food restriction, commonly found in people with eating disorders such as Anorexia Nervosa, is characterized by a persistent and intense reduction in calorie intake3–5. Chronic restrictive eating is known to cause abnormalities in the body, including in the cardiovascular system6. Post-recovery, these abnormalities can leave a lasting impact on the body7. In addition, severe food restriction (SFR) adversely affects the composition of the gut microbiome8. These changes are linked to the activation of the Renin-Angiotensin-Aldosterone System,9 increasing the risk for cardiovascular disease. Loss of microbial diversity in the gut could adversely affect nutrient absorption and utilization,10,11 resulting in weight gain difficulties and possible long-term health consequences. Using a severe food restriction model,12 we aim to examine the change in microbial species diversity of female F344 rats' gut microbiome. Rats in the experimental group undergo 40% of their normal rat diet for two weeks, while the control group receives their normal diet. After two weeks of caloric restriction, rats proceed with 3 weeks of refeeding. This 5 week cycle is repeated consecutively two more times. In both groups, fecal samples are collected. DNA is extracted and applied to 16S rRNA sequencing analysis to identify bacterial taxa and assess biodiversity changes. Phylogenetic analysis of 16S rRNA sequences after two weeks of caloric restriction indicates changes in Lactobacillus and Bacteroides populations. The results of our study emphasize the importance of diet and calorie intake in maintaining a stable microbiome, which contributes to the maintenance of well-being.<p></p>