Diet quality, gut microbiota, and microRNAs associated with mild cognitive impairment in middle-aged and elderly Chinese population

Abstract

Background Diet, the gut microbiota, and microRNAs (miRNAs) have been recognized as factors possibly influencing the pathogenesis of Alzheimer's disease. However, the combined role of diet, the gut microbiota, and miRNAs in mild cognitive impairment (MCI) has not been extensively investigated. Objectives To examine the associations among diet quality, the gut microbiota, miRNAs, and risks of MCI in middle-aged and elderly Chinese population. Methods Participants were drawn from the Effects and Mechanism Investigation of Cholesterol and Oxysterol on Alzheimer's disease (EMCOA) study. We included 2239 participants who completed comprehensive cognitive tests and dietary surveys at baseline and follow-up. Chinese Dietary Guidelines Index 2018 (CDGI-2018), Energy-Adjusted Dietary Inflammatory Index (E-DII) and Healthy Lifestyle Score (HLS) values were calculated based on data from a standard questionnaire. Changes of gut microbiota and serum miRNA expression were detected in 75 MCI and 52 healthy participants. The receiver operating characteristic curve was performed based on a logistic regression model distinguishing patients with MCI from healthy controls. Results Higher CDGI-2018 (RR, 0.75; 95% CI: 0.58–0.98) and HLS (RR, 0.54; 95% CI: 0.34–0.84) values and lower E-DII (RR, 1.46; 95% CI: 1.14–1.87) values were significantly associated with a lower risk of MCI. Lower microbial diversity and abundance of Faecalibacterium, unidentified Ruminococcaceae, and Alistipes were found in MCI participants compared with healthy controls. The abundance of ProteobacteriaandGammaproteobacteria was higher in MCI participants and was correlated with hsa-let-7g-5p, hsa-miR-107, and hsa-miR-186-3p. The predictive signatures of diet quality scores, differential gut microbiota, and serum miRNAs had good performance on distinguishing MCI participants from healthy individuals (AUC = 0.91). Conclusions A better diet quality is associated with a lower risk of MCI, which may be mediated by the microbiota composition and miRNA expression. These findings suggest that diet, the gut microbiota, and miRNAs may serve as a combinatorial biomarker to identify MCI patients and provide new insight for the diagnosis and prevention of MCI. This study was registered at the Chinese Clinical Trial Registry as ChiCTROOC-17011882.

Gut microbiota in patients with Alzheimer’s disease spectrum: a systematic review and meta-analysis

“…Table 1 summarizes the clinical and demographic characteristics of the 11 studies. These studies were performed in China [ 23 – 25 , 27 , 29 , 35 , 45 , 46 ] and U.S. [ 26 , 28 , 47 ], with a total of 378 HC and 427 patients with AD spectrum (AD = 251, MCI = 124, aMCI = 52).…”

“…The principal coordinate analyses based on both Weighted UniFrac distance and Unweighted UniFrac distances were most frequently measured. In terms of Weighted UniFrac distance, three studies revealed significant differences [ 24 , 29 , 46 ], while four studies revealed no significant differences between HC and AD spectrum [ 23 , 25 , 28 , 45 ]. In terms of Unweighted UniFrac distances, two studies revealed significances [ 24 , 29 ] while four studies revealed no significant differences between HC and AD spectrum [ 23 , 25 , 28 , 45 ].…”

“…There were obvious statistical heterogeneities among the included studies, which could be attributed to differences in dietary pattern, geographical background, center settings, and inclusion criteria of AD spectrum including various regimens, medication doses, illness duration, etc. For example, only three studies [ 23 , 46 , 47 ] in our meta-analysis conducted the dietary assessments. Nevertheless, we applied the random-model to estimate the effect sizes to reduce the influences of the heterogeneities on our results.…”

Association between healthy eating index-2015 and various cognitive domains in US adults aged 60 years or older: the National Health and Nutrition Examination Survey (NHANES) 2011–2014

“…Higher adherence to the Dietary Guidelines for Americans, assessed by HEI-2005 or HEI-2010, has been reported to be associated with higher global cognition among Puerto Rican adults living in Boston, and better cognitive performance for White and African Americans from Baltimore, respectively [ 10 , 12 ]. Likewise, in a middle-aged and elderly Chinese population, the Chinese Dietary Guidelines Index-2018 was significantly associated with a lower risk of mild cognitive impairment [ 11 ]. However, our results are inconsistent with the Women’s Health Initiative Memory Study that showed no significant associations between HEI-2010 and cognitive decline in older women [ 16 ].…”

The Potential Role of Gut Microbiota in Alzheimer’s Disease: From Diagnosis to Treatment

“…Indeed, although initially hypothesized for gastrointestinal disorders [ 102 ], gut microbiome-derived biomarkers have also been considered for psychological and neurodegenerative diseases (i.e., bipolar disorder, multiple Sclerosis, and PD), reporting powerful predictivity and differential diagnosis ability [ 103 , 104 , 105 ]. Regarding AD, promising results have recently been obtained, and Table 1 summarizes the main findings [ 72 , 73 , 106 , 107 , 108 , 109 , 110 , 111 , 112 , 113 , 114 , 115 ] ( Table 1 ). Whilst species of Prevotella and Helicobacter have been shown to be significantly different between APP/PS1 transgenic mice and controls, Actinobacteria and TM7 phylum seem to be more accurate in diagnosing AD when using the triple transgenic mouse model [ 106 , 107 , 109 ].…”