We are pleased to share the latest article in our FSHN Research Journeys series, which follows graduate students’ research in the Food Science and Human Nutrition program at The University of Florida. In this article, second-year food science master’s degree student Chris Costello describes his research into the impacts of prophylactic supplementation on gastrointestinal illness during military deployments. Read on to learn about the leading causes of morbidity during deployments, the potential of prebiotics and probiotics to prevent illnesses, and Chris’s journey to preventative medicine.

Chris: Suppose you are deployed to Location X for an extended period with limited resources and rations provided by potentially questionable sources. You have noticed (and personally experienced) frequent yet unpredictable bouts of gastrointestinal distress throughout the camp, often draining your limited medical resources and leading to mission degradation. Could some sort of prophylactic measure be taken to reduce this burden? Could probiotics or prebiotics be the answer?

Operational impacts associated with gastrointestinal illness

There is an adage in military circles that the scariest part of most deployments is the salad bar. Non-Battle-Injury (NBI) or Disease and Non-Battle-Injury (DNBI) are the leading causes of morbidity during military deployments, covering everything from malarial infections to musculoskeletal injuries to gastrointestinal illness.

Military personnel are generally considered a young and healthy representation of the U.S. population. Personnel deployed in support of contingency represent an even healthier subset of this demographic, having undergone an extensive pre-deployment medical clearance program. Despite this, travel-associated gastrointestinal illness is a perpetual issue in military medicine dating back to World War II and remains one of the most common morbidities while deployed.^1,2

A survey of over fifteen thousand US military personnel serving in southwest Asia found that 76.8% and 54.5% of personnel deployed to Iraq and Afghanistan, respectively, experienced diarrhea during their deployment.⁴  While typically associated with food- or water-borne sources, it is thought that gastroenteritis can be exacerbated by persistent deployment-related stressors that disrupt the microbiota, potentially leading to chronic complications.⁴

While this problem is well documented, the solutions are often elusive and marred by operational challenges. Most locations are typically austere and home to pathogens uncommon in many developed nations. The living conditions are often cramped. Sanitation is primitive, and sustenance sources are limited. These issues are frequently compounded by a fragile healthcare infrastructure. Thus, the environment is ripe for rampant spread of infection, often leading military healthcare professionals to take a proactive approach to gastrointestinal illness. This is where I come in.

In my research, I hope to identify strategies to reduce the impact of infectious gastroenteritis through alternative therapeutics such as probiotics or prebiotics.

My journey through preventative medicine

I am currently a U.S. Air Force Public Health Officer, charged with ensuring the health of the force and its beneficiaries through prevention. We are patient-centered, with a priority on reducing morbidity through prevention. The career field is very small, made up almost exclusively of veterinarians or public health professionals, and essentially functions as the health department on a military installation. Our department has a more clinical emphasis—such as travel medicine or occupational health—than our civilian health department counterpart.

Primarily, we work alongside healthcare professionals in the clinical outpatient setting by providing disease surveillance, prevention, and control countermeasures to practitioners and unit commanders. We deploy quite frequently, usually in small teams attached to operational units or as part of a larger medical team. With experiences spanning three continents, I have intimately witnessed the impact DNBI can have on mission effectiveness.

As we progress throughout our careers, we are offered opportunities to further our expertise in preventive medicine, ranging from epidemiology to food science to medical entomology. Dr. Renée Goodrich-Schneider was extremely helpful throughout the application process and was ultimately a big reason I chose to attend the University of Florida.

My post-graduate assignment will be to the Public Health Branch, Air Force Medical Readiness Agency at the Defense Health Headquarters in Falls Church, Virginia. Our mission, vision, and directorate overview can be found here. As a non-thesis student, I will examine the feasibility of preventative methods through a narrative review of the existing research, with the potential for future development conducted through the Department of Defense.

Prevention may be the only answer in an austere environment

Several countermeasures exist to prevent illness during military operations, more commonly referred to as Force Health Protection, which primarily hinges on two factors: location and local healthcare infrastructure. Most deployments include varying medical capabilities ranging from basic outpatient services to robust damage control resuscitation, but most (if not all) will include a small cadre of preventive medicine personnel. We continually gather medical intelligence/surveillance, perform risk assessments, and provide prophylactic recommendations.

However, there are limits to our prevention strategies, and I intend to reduce these limits. During my master’s degree studies, I will conduct a narrative review of the existing literature to identify mitigation strategies associated with gastrointestinal illness while deployed. This review will include the prophylactic supplementation of probiotics, prebiotics, or synbiotics (a formulated combination of prebiotics and probiotics) to reduce the incidence of gastrointestinal illness. Additionally, I will expand on these concepts to include the emerging fields of gut microbiota analysis and postbiotics.

Despite limitations, the future of prophylactic supplementation is bright

While probiotics and prebiotics products have seemingly exploded in the last decade with a host of purported health benefits, a disconnect from documented efficacy in vitro and in animal models can occur when compared to clinical data. Additionally, the dynamics, culturing difficulties, and share size make the gut microbiota challenging to study, adding another layer of complexity when interpreting the results from clinical trials.

Stress, sleep deprivation, and dietary changes are inevitable extrinsic factors present in every operational deployment and may confound results. Finally, probiotics often require stable environmental controls during transit; however, transportation challenges are compounded during military deployments, which are often located in remote locations with lengthy, convoluted supply chains.

Overall, I believe the future is bright in this area, and results will have direct applications to military operations and the civilian sector. While any improvements to operational readiness would likely be welcomed by military commanders, the benefits of any intervention should outweigh the costs, and this is exactly what I intend to analyze.

Chris is a Major in the U.S. Air Force attending the University of Florida on a 24-month fellowship sponsored through the Air Force Institute of Technology in Wright-Patterson Air Force Base, Ohio. He is pursuing his master’s degree in food science under the guidance of Dr. Renée Goodrich-Schneider. He was born and raised in Waterbury, Connecticut, and joined the U.S. Air Force as an Emergency Medical Technician at the age of 18. He received his undergraduate degree in biological sciences from the University of California, Davis, and his Master of Public Health from Touro University, California. He is happily married with one daughter and loves playing and watching sports, exercising, and all things UConn.    

References

1. Riddle, M. S., Savarino S. J., & Sanders, J. W., (2015) Gastrointestinal Infections in Deployed Forces in the Middle East Theater: An Historical 60 Year Perspective. American Journal of Tropical Medicine and Hygiene 93(5). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4703254/
2. Murray C. K., & Horvath L. L., (2006) An approach to prevention of infectious diseases during military deployments. Clinical Infectious Disease 3(44). https://pubmed.ncbi.nlm.nih.gov/17205453/
3. Riddle, M. S., Martin G. J., Murray, C. K., et al. (2017) Management of Acute Diarrheal Illness During Deployment: A Deployment Health Guideline and Expert Panel Report. Military Medicine. S2(34-52). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5657341/
4. Kent K.G., (2021) Prevalence of gastrointestinal disease in US Military Veterans under outpatient care at the Veterans Health Administration. SAGE Open Medicine 8(9). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8504213/

Looking for more posts exploring graduate research projects in the FSHN Department at the University of Florida?

Dive into the Research Journeys of other graduate students below.

M.S. Food Science
M.S. Nutritional Sciences
Ph.D. Food Science
Ph.D. Nutritional Sciences

3