Comprehensive modulatory effects of whole grain consumption on immune-mediated inflammation in middle-aged and elderly community residents: A real-world randomized controlled trial
Cheng Li, Yaru Li, Nan Wang, Zhiwen Ge, Jia Wang, Bingjie Ding, Yanxia Bi, Yuxia Wang, Yisi Wang, Zebin Peng, Xinli Yang, Congcong Wang, Zhongxin Hong
Abstract
Whole grain consumption is widely recognized as a vital component of a balanced diet. Dietary fiber has been well-documented to play a crucial role in these health benefits attributed to whole grain intake. However, population-based evidence directly linking whole grain consumption to anti-inflammatory effects, especially in the context of immune-mediated inflammation, remains limited. We hypothesized that whole grain consumption promotes health by modulating immune-mediated inflammation. This study was designed as a real-world, population-based randomized controlled trial. We compared the effects of whole grain versus refined grain consumption on immune-mediated inflammation through staple food substitution, while participants maintained their usual dietary practices. The results demonstrated that whole grain consumption significantly reduced circulating levels of pro-inflammatory cytokines IL-22 and IL-23 compared to refined grain consumption. These reductions were associated with optimized short-chain fatty acid profiles and changes in CD4 + T cell subset distributions. The findings suggest that the anti-inflammatory effects of whole grain consumption in middle-aged and elderly populations are mediated by targeting specific CD4 + T cell subsets, in addition to modulating both upstream short-chain fatty acid composition and downstream expression of the pro-inflammatory cytokines IL-22 and IL-23. • In this investigation, we employed a method of substituting staple foods to examine the impact of varying grain consumption on immune-mediated inflammation and its associated metabolic endpoints. • Whole grains exhibit a comprehensive anti-inflammatory effect mediated by immune-induced inflammatory responses, involving T cell subsets, upstream short-chain fatty acids, and downstream inflammatory cytokines. • Whole grains may exert anti-inflammatory effects by reducing the circulating levels of IL-22 and IL-23. This effect may be linked to improvements in short-chain fatty acid composition and the distribution of CD4+T cells.