Leucine-Restricted Diet Ameliorates Obesity-Linked Cognitive Deficits: Involvement of the Microbiota–Gut–Brain Axis
Danna Wang, Luyao Wang, Liuyang Han, Boyang Wang, Renjie Shi, Ye Jin, Bing Xia, Zhenting Zhao, Beita Zhao, Xuebo Liu
Abstract
Leucine restriction (LR) improves insulin resistance and promotes white adipose tissue browning. However, the effect of LR on obesity-associated cognitive impairment remains unclear. The present study found that an 8-week LR dramatically improved high-fat diet (HFD)-induced cognitive decline by preventing synaptic dysfunction, increasing the expressions of neurotrophic factors, and inhibiting neuroinflammation in memory-related brain regions. Moreover, LR notably reshaped the structure of gut microbiota, which was manifested by downregulating the Firmicutes/Bacteroidetes ratio, reducing the relative abundance of inflammation-related bacteria including Acetatifactor, Helicobacter, Mucispirillum, and Oscillibacter but increasing short-chain fatty acid (SCFA)-producing bacterial genera including Alistipes, Allobaculum, Odoribacter, and Olsenella . Notably, HFD-caused SCFA reduction, gut barrier damage, and LPS leakage were recovered by LR. Our findings suggested that LR could serve as an effective approach to attenuate obesity-induced cognitive deficits, which may be achieved by balancing gut microbiota homeostasis and enhancing SCFA production.