Effects of lactotripeptide ingestion and physical activity intervention on the fatigue status of middle-aged and older adults: a randomized controlled trial

This randomized controlled trial aimed to investigate the effects of eight weeks of lactotripeptide (LTP) ingestion, physical activity (PA) intervention, and combined intervention on the fatigue status of middle-aged and older adults. A total of 78 middle-aged and older adults (63 ± 8 years of age) were randomly assigned to four groups: placebo, LTP, placebo with PA intervention (placebo + PA), and LTP with PA intervention (LTP + PA). All participants ingested the placebo or LTP tablets daily (three tablets/day). The placebo + PA and LTP + PA groups participated in a weekly supervised exercise class and were instructed to increase their moderate- to vigorous-intensity PA at home. The visual analog scale, Brief Fatigue Inventory, Profile of Mood States second edition (POMS2), and Beck Depression Inventory second edition (BDI-II) were administered before and after the intervention. No significant interactions or main effects were observed between LTP ingestion and PA intervention on any of the fatigue scales. The main-effect analyses revealed that the PA intervention improved the total mood disturbance score of the POMS2 (F = 5.22, P = 0.03) and BDI-II score (F = 4.81, P = 0.03). After the post hoc paired comparisons, the total mood disturbance and BDI-II scores improved more with the combined intervention than with the PA intervention alone (percentage difference between the effect of combined intervention and PA intervention alone was 3.7% for total mood disturbance score and 13.7% for BDI-II score). The present study suggests that eight weeks of LTP ingestion and PA intervention did not have a significant effect on fatigue status. However, the PA intervention improved mood status and depressive symptoms, and these effects were enhanced by LTP ingestion.

Long-distance translocation of CLAVATA3/ESR-related 2 peptide and its positive effect on roots sucrose status

In vascular plants, roots anchor themselves into the soil and take up water and nutrients to provide them to the shoots. Therefore, continuous growth and development of the roots are important for plant life. To achieve this, photosynthesizing leaves must be able to supply sufficient photoassimilates to the roots. However, the mechanisms by which plants maintain carbon levels in roots remain elusive. Here, we focused on the Arabidopsis (Arabidopsis thaliana) CLAVATA3/ESR-related 2 (CLE2) peptide, which was detected in Arabidopsis xylem exudate, and its homologs. CLE2 and CLE3 genes responded to carbon-deficient conditions. Loss- and gain-of-function mutant analyses showed that CLE genes positively affected root sucrose level. Mutations in the CLE genes resulted in a high shoot/root ratio under sucrose-free conditions. Grafting experiments demonstrated the systemic effect of CLE peptide genes. These findings provide insights into the molecular basis for the relationship between roots and leaves in maintenance of the root sucrose levels and growth.