Altered gut microbiota in older adults with mild cognitive impairment: a case-control study

Kang-Chen Fan; Chen-Ching Lin; Yi-Chien Liu; Yi-Ping Chao; Yen-Jun Lai; Yen-Ling Chiu; Yi-Fang Chuang

doi:10.3389/fnagi.2023.1162057

Altered gut microbiota in older adults with mild cognitive impairment: a case-control study

Front Aging Neurosci. 2023 May 25:15:1162057. doi: 10.3389/fnagi.2023.1162057. eCollection 2023.

Authors

Kang-Chen Fan¹, Chen-Ching Lin², Yi-Chien Liu³, Yi-Ping Chao^{4

5}, Yen-Jun Lai⁶, Yen-Ling Chiu^{7

8

9}, Yi-Fang Chuang^{1

10

11}

Affiliations

¹ School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan.
² Institute of Biomedical Informatics, National Yang Ming Chiao Tung University, Taipei, Taiwan.
³ Department of Neurology, Cardinal Tien Hospital, New Taipei, Taiwan.
⁴ Department of Computer Science and Information Engineering, Chang Gung University, Taoyuan, Taiwan.
⁵ Department of Otolaryngology-Head and Neck Surgery, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan.
⁶ Division of Medical Imaging, Department of Radiology, Far Eastern Memorial Hospital, New Taipei, Taiwan.
⁷ Department of Medical Research, Far Eastern Memorial Hospital, Taipei, Taiwan.
⁸ Graduate Program in Biomedical Informatics and Graduate Institute of Medicine, Yuan Ze University, Taoyuan, Taiwan.
⁹ Graduate Institute of Clinical Medicine, National Taiwan University, Taipei, Taiwan.
¹⁰ Institute of Public Health, National Yang Ming Chiao Tung University, Taipei, Taiwan.
¹¹ Department of Psychiatry, Far Eastern Memorial Hospital, New Taipei, Taiwan.

Abstract

Introduction: The microbiota-gut-brain axis is implicated in Alzheimer's disease. Gut microbiota alterations in mild cognitive impairment (MCI) are inconsistent and remain to be understood. This study aims to investigate the gut microbial composition associated with MCI, cognitive functions, and structural brain differences.

Methods: A nested case-control study was conducted in a community-based prospective cohort where detailed cognitive functions and structural brain images were collected. Thirty-one individuals with MCI were matched to sixty-five cognitively normal controls by age strata, gender, and urban/rural area. Fecal samples were examined using 16S ribosomal RNA (rRNA) V3-V4 sequencing. Compositional differences between the two groups were identified and correlated with the cognitive functions and volumes/thickness of brain structures.

Results: There was no significant difference in alpha and beta diversity between MCIs and cognitively normal older adults. However, the abundance of the genus Ruminococcus, Butyricimonas, and Oxalobacter decreased in MCI patients, while an increased abundance of nine other genera, such as Flavonifractor, were found in MCIs. Altered genera discriminated MCI patients well from controls (AUC = 84.0%) and were associated with attention and executive function.

Conclusion: This study provides insights into the role of gut microbiota in the neurodegenerative process.

Keywords: 16S ribosomal RNA; cognitive functions; gut microbiota; mild cognitive impairment; structural brain imaging.