The Gut Brain Axis: Beyond Sleep

 

Are the bacteria in your gut controlling your brain? Research findings suggest a strong link between the microbiome and brain functioning classified as the “Gut-Brain Axis" (or GBA). The gut microbiome naturally plays a regulatory role in the digestion of various food content. Vitaterna et. al. documented the intriguing relationship between the gut microbiome and circadian rhythm regulation in the paper, “A Prebiotic Diet Alters the Fecal Microbiome and Improves Sleep in Response to Sleep Disruption in Rats”. Their research team posited that shifts in rat diet, specifically an increase in the levels of prebiotics (such as Galactooligosaccharides (GOS) and polydextrose (PDX), can lead to changes in sleeping patterns. Probiotic shifts in diet correlate with positive sleep results such as increased sleep recovery and more time spent in NREM sleep. Their research provides clear evidence of the effects of the Gut-Brain Axis on sleep.

While Vitaterna et. al. isolated this specific relationship between the gut microbiome and the brain, recent studies have appeared analyzing the effect of the GBA on behavior. Articles investigate how the gut microbiome may also play a more complex role in mood regulation. Limbana et. al. (2018) analyzed this phenomenon in-depth in their paper, “Gut Microbiome and Depression: How Microbes Affect the Way We Think”. Limbana’s research team conducted a literature review to find specific articles discussing the relationship between the microbiome and the development of depression. Their literature review showed an often-implicated correlational relationship between a decrease in microbiome diversity and an increase in rates of depression. However, the causality of the relationship is unknown as we are still unsure if changes in the gut lead to depression or if depression results in microbiome shifts. 

Research has also shown a link between inflammation of the GI tract and the development of depression. Gut inflammation is linked with high-fat dieting. When participants consume a Mediterranean diet (typically a more rounded diet), research often shows a decrease in depression rates when compared to a Western Diet (a diet with a higher fat content). Ultimately, the paper concludes that more research needs to be done in the burgeoning field to highlight potential relationships between cognitive changes and the gut microbiome.

Both papers contribute to our understanding of how our microbiome affects our mental processing in individual ways. The article by Vitaterna et. al uses lab work to analyze the relationship between changes in circadian rhythm associated with the microbiome. The study from Limbana et. al. conducts a literature review to analyze the relationship between mood and microbiome diversity. However, both of these articles represent how the field of microbiology is becoming ever more intertwined with Behavioral Neuroscience. 

Works Cited

Bowers, Samuel J., Keith C. Summa, Robert S. Thompson, Antonio Gonzalez, Fernando 

Vargas, Christopher Olker, Peng Jiang, et. al. “A Prebiotic Diet Alters the Fecal Microbiome and Improves Sleep in Response to Sleep Disruption in Rats.” Frontiers in Neuroscience (2022) Frontiers | A Prebiotic Diet Alters the Fecal Microbiome and Improves Sleep in Response to Sleep Disruption in Rats (frontiersin.org)

Limbana T, Khan F, Eskander N. Gut Microbiome and Depression: How Microbes Affect the 

The Way We Think. Cureus. 2020 Aug 23;12(8):e9966. doi: 10.7759/cureus.9966. PMID: 32983670; PMCID: PMC7510518. Gut Microbiome and Depression: How Microbes Affect the Way We Think - PMC (nih.gov)