Characterization of the gut microbiota among Veterans with unique military-related exposures and high prevalence of chronic health conditions: A United States-Veteran Microbiome Project (US-VMP) study

Abstract

The gut microbiome is impacted by environmental exposures and has been implicated in many physical and mental health conditions, including anxiety disorders, affective disorders, and trauma- and stressor-related disorders such as posttraumatic stress disorder (PTSD). United States (US) military Veterans are a unique population in that their military-related exposures can have consequences for both physical and mental health, but the gut microbiome of this population has been understudied. In this publication, we describe exposures, health conditions, and medication use of Veterans in the US Veteran Microbiome Project (US-VMP) and examine the associations between these characteristics and the gut microbiota. This cohort included 331 US Veterans seeking healthcare with the Veterans Health Administration who were 83% male with an average (±SD) age of 47.6 ​± ​13.4 years. The cohort displayed a high prevalence of PTSD (49.8%) and history of traumatic brain injuries (76.1%), and high current use of prescription medications (74.9%) to treat various acute and chronic conditions. We observed significant associations between the gut microbiota composition and gastroenteritis, peripheral vascular disease (PVD), bipolar disorders, symptoms of severe depression based on the Beck Depression Inventory, stimulant and opioid use disorders, beta-blockers, serotonin and norepinephrine reuptake inhibitor antidepressants, diabetes medications, and proton pump inhibitors. Many of the Veteran characteristics examined were associated with altered relative abundances of specific taxa. We found that PVD and cardiovascular disease were associated with lower microbiota diversity in the gut (i.e., α-diversity), while supplemental vitamin use was associated with higher α-diversity. Our study contributes novel insights as to whether the unique exposures of Veterans in this cohort correlate with gut microbiota characteristics and, in line with previous findings with other population-level studies of the microbiome, confirms associations between numerous health conditions and medications with the gut microbiome.

The impact of electroacupuncture on anxiety-like behavior and gut microbiome in a mouse model of chronic restraint stress

“…Anxiety disorders represent the most prevalent category of mental illnesses, encompassing conditions such as generalized anxiety disorder (GAD), separation anxiety, selective mutism, specific phobias, social anxiety disorder (SAD), panic disorder, and agoraphobia ( Penninx et al, 2021 ). The link between dysbacteriosis (microbial imbalances) and anxiety disorders, spanning the spectrum of anxiety conditions ( Stanislawski et al, 2021 ) including specific subtypes like GAD ( Chen et al, 2019 ) and SAD ( Butler et al, 2023 ), has been extensively studied. Additionally, preclinical research has delved into the influence of gut microbiota on behaviors related to anxiety ( Neufeld et al, 2011 ).…”

Meeting report of the sixth annual tri-service microbiome consortium symposium

“…The session closed with a discussion of discerning alterations in gut, oral, and skin microbiomes associated with chronic physical and psychological health conditions and medication use, as part of the United States-Veteran Microbiome Project [10][11][12]. The goal is to better understand the relationship between human microbiota, health conditions in veterans, and effectiveness of medications.…”

Twenty Important Research Questions in Microbial Exposure and Social Equity

“…Veteran Microbiome Project has begun research into the skin, gut, and oral microbiome of an unstably housed population. Initial results showed that the frequency of homelessness was associated with gut microbial composition ( 9 ), thereby prompting future work focused on potential relationships between unstable housing, the microbiome, and physical and mental health.…”