Time-restricted feeding restores obesity-induced alteration in adipose tissue immune cell phenotype

Authors: LEE, YOUNGYOON - Chungbuk National University; KIM, YELIM - Chungbuk National University; LEE, MINAM - Chungbuk National University; WU, DAYONG - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; PAE, MUNKYONG - Chungbuk National University

Submitted to: Nutrients
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/23/2021
Publication Date: 10/25/2021
Citation: Lee, Y., Kim, Y., Lee, M., Wu, D., Pae, M. 2021. Time-restricted feeding restores obesity-induced alteration in adipose tissue immune cell phenotype. Nutrients. 13(11):3780. https://doi.org/10.3390/nu13113780.
DOI: https://doi.org/10.3390/nu13113780

Interpretive Summary: The metabolic benefits of time-restricted feeding (TRF) are documented in various studies. However, the effects of TRF on immune cells are relatively unknown. Since obesity has been shown to alter immune function, this study investigated the therapeutic effects of TRF on high-fat, diet-induced obese mice. Supported by The National Research Foundation of Korea (NRF) grant funded by the Korea government and the U.S. Department of Agriculture, researchers evaluated whether TRF affects immune cell populations and inflammatory markers in fat tissue, as well as, changes in body weight, fat mass, and glucose tolerance. This study showed that TRF intervention reduced HFD-induced weight gain, decreased insulin resistance and improved glucose tolerance. This suggests that TRF restores the obesity-induced alteration in immune cell composition, which may in part contribute to health benefits. Specifically, TRF may significantly help in fighting against systemic insulin resistance and glucose intolerance, and possibly also other related metabolic disorders.

Technical Abstract: Studies suggest that time-restricted feeding (TRF) may prevent obesity and its commodities. At present, little is known about how TRF impacts immune cells, and whether such an effect is linked to altered metabolic parameters under condition of a high-fat diet (HFD)-induced obesity. To address these issues, we conducted a study in which we determined whether TRF has therapeutic efficacy against weight gain, adiposity, as well as associated immune cell disturbance found in obese mice. Six week-old male C57BL/6 mice were fed a low-fat diet (LFD) or HFD ad libitum for six weeks, after which time a subgroup of HFD mice was switched to the 10 h TRF paradigm (HFD-TRF) for additional eight weeks. We found that TRF intervention reduced HFD-induced weight gain. Even with comparable fat mass and mean adipocyte area, the HFD-TRF group had lower mRNA levels of proinflammatory cytokine Tnf-alpha and chemokine Ccl8, along with reduced numbers of adipose tissue macrophages (ATM), CD11c+ ATM, and CD8+ T cell compared to the HFD group, while maintaining CD8+ to CD4+ ratio at levels similar to those in the LFD group. Furthermore, TRF intervention was effective in improving glucose tolerance and reducing HOMA-IR. Taken together, our findings suggest that TRF restores the obesity-induced alteration in immune cell composition, and this effect may in part contribute to health benefits (including insulin sensitivity) of practicing TRF.