The Relationship between Gut Microbiome and Cognition in Older Australians

Abstract

Ageing is associated with changes in biological processes, including reductions in cognitive functions and gut microbiome diversity. However, not much is known about the relationship between cognition and the microbiome with increasing age. Therefore, we examined the relationship between the gut microbiome and cognition in 69 healthy participants aged 60–75 years. The gut microbiome was analysed with the 16S rRNA sequencing method. The cognitive assessment included the Cognitive Drug Research computerised assessment battery, which produced five cognitive factors corresponding to ‘Quality of Episodic Secondary Memory’, ‘Quality of Working Memory’, ‘Continuity of Attention, ‘Speed of Memory’ and ‘Power of Concentration’. Multiple linear regression showed that the bacterial family Carnobacteriaceae explained 9% of the variance in predicting Quality of Episodic Secondary Memory. Alcaligenaceae and Clostridiaceae explained 15% of the variance in predicting Quality of Working Memory; Bacteroidaceae, Barnesiellaceae, Rikenellaceae and Gemellaceae explained 11% of the variance in Power of Concentration. The present study provides specific evidence of a relationship between specific families of bacteria and different domains of cognition.

The Interplay between Gut Microbiota and Cognitive Functioning in the Healthy Aging Population: A Systematic Review

“…Haimov et al [ 32 ] included insomniacs from a community center, but they were not part of any clinical population. In the other three articles, participants were derived from existing cohorts recruited for other study purposes, such as the TwinsUK British twin cohort [ 35 ], the Australian Research Council Longevity Intervention (ARCLI) [ 33 ], and an unspecified longitudinal study conducted in the southeastern United States [ 31 ]. Canipe et al [ 31 ] and Komanduri et al [ 33 ] reported that their participants underwent assessments for medical conditions.…”

Liuwei Dihuang Decoction Alleviates Cognitive Dysfunction in Mice With D-Galactose-Induced Aging by Regulating Lipid Metabolism and Oxidative Stress via the Microbiota-Gut-Brain Axis

“…Previous studies have confirmed that Lactobacillales can improve the gut microbiota in aging rats (Hor et al, 2019), inhibit oxidative stress , and improve cognitive function in aged mice (Ni et al, 2019). Higher Clostridiaceae abundance correlates with better "attention continuity" (Komanduri et al, 2021). Previous studies have shown that a high abundance of Alistipes can effectively suppress intestinal inflammation and oxidative stress (Wan et al, 2021).…”

Severe cognitive decline in long-term care is related to gut microbiome production of metabolites involved in neurotransmission, immunomodulation, and autophagy

“…Ageing-associated gut microbiome characteristics (Claesson et al, 2011; Meyer et al, 2022) are linked to progressive frailty and cognitive decline (Komanduri et al, 2021; Manderino et al, 2017; Meyer et al, 2022; Verdi et al, 2018). External exposures that disrupt the microbiome, such as antibiotics, can further contribute to altered neurological homeostasis and poorer cognitive outcomes (Desbonnet et al, 2015; Frohlich et al, 2016; Lynn et al, 2021).…”

“…For example, Verdi and colleagues identified significantly lower faecal microbiota diversity to be associated with longer reaction times (in cognitive assessments) in an independently living aged cohort (Verdi et al, 2018). Similarly, Wasser and colleagues reported reduced alpha diversity in those with Huntington's disease (Wasser et al, 2020), while two other studies have reported no significant relationship between CI severity and alpha diversity (Komanduri et al, 2021;Stadlbauer et al, 2020). In our analysis, where age was adjusted for, a contrary effect was observed, consistent with an association between CI and specific microbiome changes that is separate to wider microbial shifts that are typical in later life.…”