Effect of dietary protein content shift on aging in elderly rats by comprehensive quantitative score and metabolomics analysis

Abstract

In the protein nutrition strategy of middle-aged and elderly people, some believe that low protein is good for health, while others believe high protein is good for health. Facing the contradictory situation, the following hypothesis is proposed. There is a process of change from lower to higher ratio of protein nutritional requirements that are good for health in the human body after about 50 years of age, and the age at which the switch occurs is around 65 years of age. Hence, in this study, 50, 25-month-old male rats were randomly divided into five groups: Control (basal diet), LP (low-protein diet with a 30% decrease in protein content compared to the basal diet), HP (high-protein diet with a 30% increase in protein content compared to the basal diet), Model 1 (switched from LP to HP feed at week 4), and Model 2 (switched from LP to HP feed at week 7). After a total of 10 weeks intervention, the liver and serum samples were examined for aging-related indicators, and a newly comprehensive quantitative score was generated using principal component analysis (PCA). The effects of the five protein nutritional modalities were quantified in descending order: Model 1 > HP > LP > Control > Model 2. Furthermore, the differential metabolites in serum and feces were determined by orthogonal partial least squares discriminant analysis, and 15 differential metabolites, significantly associated with protein intake, were identified by Spearman’s correlation analysis (p < 0.05). Among the fecal metabolites, 10 were positively correlated and 3 were negatively correlated. In the serum, tyrosine and lactate levels were positively correlated, and acetate levels were negatively correlated. MetaboAnalyst analysis identified that the metabolic pathways influenced by protein intake were mainly related to amino acid and carbohydrate metabolism. The results of metabolomic analysis elucidate the mechanisms underlying the preceding effects to some degree. These efforts not only contribute to a unified protein nutrition strategy but also positively impact the building of a wiser approach to protein nutrition, thereby helping middle-aged and older populations achieve healthy aging.

Longevity-Associated Core Gut Microbiota Mining and Effect of Mediated Probiotic Combinations on Aging Mice: Case Study of a Long-Lived Population in Guangxi, China

“…The probiotic properties of the screened Lactobacillus fermentum and Bacteroides fragilis were ranked using principal component analysis concerning a comprehensive quantification method in the literature [ 27 ]. The three leading indicators chosen for this study were gastrointestinal tolerance, self-cohesion, and hydrophobicity.…”

A protein restricted diet induces a stable increased fat storage phenotype in flies

“…The interaction of these amino acids with other amino acids and/or metabolites may compromise multiple organ and/or whole organism molecular and physiological homeostatic functions, leading to disease and reduced lifespan [16] . Suggested mechanisms of action for the remedial and beneficial effects of PRD include; stimulated hydrogen sulfate (neurotransmitter) production [23] , increased carbohydrate metabolism and accelerated tri-carboxylic acid cycle (TCA) activity [24] , increased mitochondrial biogenesis and antioxidant activity [25] , [26] , increased cellular proteostasis and autophagy [7] , [27] , [28] , reduced signaling of growth hormone/insulin like growth factor-1 (GH/IGF-1) pathway [29] , reduced signaling of amino acid sensitive mechanistic target of rapamycin complex 1 (mTORC1) pathway [30] , [31] , [32] , [33] and increased activation of fibroblast growth factor 21 (FGF21) hormone [34] , [35] .…”