Microbiome-Gut-Brain Axis: Probiotics and Their Association With Depression

Abstract

To assess the association of probiotics with depression, a large population-based cross-sectional study was conducted. National Health and Nutrition Examination Survey adult participants from 2005 through 2012 were included. Exposure was defined as having consumed any probiotic food or supplement on any of the interview days. Subjects were classified as depressed if Patient Health Questionnaire scores were ≥10. Of the 18,019 subjects included, 14.11% consumed probiotics. Unadjusted analysis suggested that subjects who consumed probiotics had lower odds of depression (OR=0.58, 95% CI=0.45-0.75). After adjustment for characteristics associated with depression and probiotic exposure, the effect was attenuated (OR=0.82, 95% CI=0.61-1.1) and no longer significant. Use of probiotics is not associated with lower rates of depression in this national sample.

The Maternal Gut Microbiome During Pregnancy

“…The discovery of two-way signaling between the gut and brain has led to this system being coined, the “Brain-Gut Axis” (Foster & McVey Neufeld, 2013; Gareau, 2014). In a healthy individual, the autonomic nervous system (ANS), the enteric nervous system (ENS), the hypothalamic-pituitary-adrenal (HPA) axis, and the immune system work in synchrony bidirectionally between brain and gut (Cepeda, Katz, & Blacketer, 2016; Foster & McVey Neufeld, 2013). When there is a disruption of any of the components of this system, disease may manifest (Foster & McVey Neufeld, 2013; Gareau, 2014).…”

“…When there is a disruption of any of the components of this system, disease may manifest (Foster & McVey Neufeld, 2013; Gareau, 2014). The bidirectional nature of the brain-gut axis, magnified by gut inflammation, can impact the central nervous system, body weight, immune status and behavior (Cepeda et al, 2016) (see Figure 1). …”

Exploring the microbiome in health and disease

“…Alterations in the gut microbiome are also associated with neuropsychiatric disorders, such as schizophrenia, bipolar disorder, autism, major depressive disorder, chronic fatigue syndrome, anxiety, and stress, [316][317][318][319] as well as neurodegenerative diseases (Parkinson's disease (PD), AD, dementia, and stroke). 313 …”

“…In contrast, similar administration of a combination of L. rhamnosus and B. animalis in patients diagnosed with schizophrenia saw no difference in the psychiatric symptom severity between the placebo and probiotics groups. 311 Contradictory results have emerged from depressed patients who consumed probiotics; while in some studies the use of probiotics seemed not to be associated with lower rates of depression, 318 in other studies the probiotic treatment produced a reduction in network-level neural reactivity to negative emotions, anxiolytic activity, suppression of psychological stress, and reduction of the negative thoughts associated with low mood. 343 …”

Astrofood, Priorities and Pandemics: Reflections of an Ultra-Processed Breakfast Program and Contemporary Dysbiotic Drift

“…The mechanisms by which microbes can influence brain development, cognition and behavior include, but are not limited to: direct and indirect microbial interactions with the immune system, enhancement of nutrient bioavailability and neurotransmitter precursors, maintenance of the gastrointestinal lining, reduction of oxidative stress, direct gut microbe-to-brain communication via the vagus nerve which connects the intestinal tract to the emotional centers of the brain, and transformation of dietary phytochemicals into bioactive compounds which subsequently influence mood [21,128]. But as we will explore in more detail below concerning the cost of diets, the application of probiotics and specialized fermented products are expensive and unlikely to represent a primary solution to the nutritional drivers of NCDs [129]. In other words, Astrofood wouldn't have been complete if it had a probiotic in its cream-like filling.…”