Measuring phenotypic flexibility by transcriptome time-course analyses during challenge tests before and after energy...

Area of Science:

• Nutritional science
• Genomics
• Metabolic research

Background:

• Dietary interventions significantly impact health.
• Transcriptomics offers detailed insights into diet effects.
• Dynamic gene expression changes during metabolic tests are not fully understood.

Purpose of the Study:

• To investigate if transcriptome time-course analyses during challenge tests provide more information on dietary effects than static measurements.
• To assess the impact of a 12-week 20% energy restriction (ER) diet on gene expression.
• To compare the effectiveness of oral glucose tolerance tests (OGTT) and mixed-meal tests (MMT) in capturing dietary-induced changes.

Main Methods:

• Seventy-two healthy, overweight adults (50-65 years) underwent 12 weeks of 20% ER or control diet.
• Whole-genome gene expression in peripheral blood mononuclear cells was analyzed.
• Measurements were taken during fasting, OGTT (30, 60, 120 min), and MMT (60, 120, 240, 360 min) before and after the intervention.

Main Results:

• ER led to faster, more pronounced down-regulation of oxidative phosphorylation, cell adhesion, and DNA replication genes during OGTT compared to controls.
• MMT showed less consistent effects on gene expression.
• Transcriptome time-course analysis during OGTT revealed dynamic cellular adaptations.

Conclusions:

• Oral glucose tolerance tests combined with transcriptomics are effective in measuring dynamic cellular adaptation to dietary interventions.
• Dynamic transcriptome analyses during challenge tests offer superior insights into diet effects compared to static fasting measurements.
• Energy restriction induces significant, measurable changes in gene expression patterns.