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Published on: June 2, 2022
Microbiota-induced inflammation mediates the impacts of a Western diet on hippocampal-dependent memory
Eden Crain1, Dulce M Minaya1, Claire B de La Serre2
1Department of Nutritional Sciences, University of Georgia, Athens, GA, USA.
Abstract:
Obesity is associated with impaired hippocampal-dependent memory, but the mechanisms driving this pathology are not fully understood. Western diets (WD) contribute to obesity, and previous reviews have described a role for WD in impaired hippocampal-dependent memory. However, there is need for a more detailed description of the pathways by which WD may impair memory. The short vs long-term effect of specific dietary components on brain structure and functions as well as the precise mechanism and molecular pathways involved are still not fully understood. This review focuses on the mechanisms and effects of gut microbiota-driven neuroinflammation. WD leads to changes and imbalance in bacterial taxa abundances that are deleterious to the host health (gut dysbiosis) and studies in rodent models show these changes are sufficient to impair hippocampal-dependent memory. Here, we discuss a variety of proposed mechanisms linking microbiota composition to hippocampal function, with a focus on neuroinflammation. Gut microbiota impacts gastrointestinal barrier function, leading to increased circulating proinflammatory bacterial products, increased blood-brain barrier permeability, and neuroinflammation.
Insights
Western diets (WD) disrupt gut bacteria, leading to gut dysbiosis and neuroinflammation, which impairs memory. This review details how diet-induced gut changes affect brain function and memory.
Area of Science:
- Neuroscience
- Microbiology
- Nutrition Science
Background:
- Obesity is linked to impaired hippocampal memory function.
- Western diets (WD) contribute to obesity and are implicated in memory deficits.
- Mechanisms linking WD, gut microbiota, and memory impairment require detailed elucidation.
Purpose of the Study:
- To review the mechanisms by which WD-induced gut dysbiosis leads to neuroinflammation and impairs hippocampal-dependent memory.
- To explore the role of gut microbiota in mediating the effects of WD on brain function.
Main Methods:
- Literature review focusing on studies investigating the impact of WD on gut microbiota composition and neuroinflammation.
- Analysis of proposed molecular pathways linking gut dysbiosis to hippocampal dysfunction.
- Examination of rodent model studies demonstrating the causal link between gut microbiota changes and memory impairment.
Main Results:
- WD induce gut dysbiosis, altering bacterial taxa abundances.
- Gut dysbiosis negatively impacts gastrointestinal barrier function.
- Increased circulating pro-inflammatory bacterial products and blood-brain barrier permeability contribute to neuroinflammation and memory deficits.
Conclusions:
- Gut microbiota dysbiosis driven by WD is a key mechanism underlying hippocampal memory impairment.
- Neuroinflammation, triggered by gut-derived inflammatory mediators, plays a critical role in this process.
- Further research into specific dietary components and molecular pathways is needed to fully understand and potentially mitigate these effects.
