Gaining superpowers through modified gut microbiology sounds like the backstory for an unlikely Marvel character, but that’s what the U.S. Office of Naval Research aims to do with a program dubbed Gut Microbiology for Warfighter Resilience. Researchers are engineering microbes not just to make warfighters tougher, but also less fearful and “with the intent of … conferring new capabilities.”
There is solid science behind this seemingly far-out program. Resilience is sometimes seen as a matter of character, but the reality is more complex. Microbiology plays a part and may help troops handle the stresses of a combat deployment, among other things.
“Does the gut microbiome play a role in host response to physical and psychosocial stressors, and if so, can we envision ways to manipulate the microbiome to minimize negative responses?” was program lead Dr. Linda Chrisey’s provocative opening question to the Tri-Service Conference.
The gut microbiome is the population of trillions of commensal bacteria, fungi and viruses, performing vital work in keeping us healthy. As any traveler knows, you disrupt your gut flora at your peril. But the gut microbiome does much more than keep your digestion working: recent research shows it influences not just the immune system but also the brain and things like perception of pain.
‘Guts’ and ‘intestinal fortitude’ are as synonyms for courage and determination. The association between bravery and bowels is an obvious one. What is less obvious is what researchers call the gut-microbiota-brain axis: your guts affect your brains just as much as the other way around. Disrupt a mouse’s gut biota and it shows more anxiety. The gut microbiome influences emotional behavior, anxiety, memory and cognitive function. So a tougher biome could mean more resilient troops.
Military deployment brings sudden changes in environment, disrupted sleep patterns, long shifts, “sporadic nutrition” – missed meals and hasty snacks — and, not infrequently, anticipatory anxiety about what lies ahead. All these stressors affect gut microbiota, which in turn affect the brain in a feedback loop.
Chrisey gave a tentative affirmative answer to her opening question of whether the biome influences resilience, suggesting that stress factors might be reduced by manipulating gut microbiota with prebiotic or probiotic foodstuffs.
While probiotics to counter deployment stress is novel enough (military-strength yogurt drink, anyone?) the program is also looking at “the host/microbiome interactions that relate to sensory systems such as auditory and olfactory systems.” In other words, tweaking gut bacteria to sharpen your hearing or sense of smell.
Surprisingly, this is also just following on recently established science. For example, it has been shown that your sense of smell is influenced by your biome, and this can make the different between so-called “super smellers” and “hyposmic” individuals with an impaired sense of smell.
The program description also mentions modifications to stave off hypothermia in extreme cold, and adjust the body clock which otherwise makes us sluggish when it is time to sleep. Cold-proof, 24-hour warfighters would certainly be more capable.
Perhaps most significantly, researchers are also homing in on brain function. The link with anxiety, which might nudge someone along the axis between fear and bravery, has already been mentioned. Whether the biome also influences cognitive ability is also an open question. Gut microbiota may be a significant contributor to Alzheimer’s and other forms of neural degeneration. Does this mean you make people sharper, quicker-thinking and clearer-headed by tweaking their biome in a positive way? It’s an intriguing possibility. ONR-funded research published earlier this year showed a link between the microbiome and memory in mice, suggesting there are avenues to be explored.
The U.S. Air Force has long used ‘Go pills’ and ‘No go pills’ to help aircrew handle fatigue and disruption to their daily rhythms – often with some controversy. The new approach could be safer and more effective while having less chance of side effects and a greater range of applications, though obviously thorough testing is essential.
DARPA is already developing an implant called ADAPTER containing special bacteria to release antibiotics into the gut on demand. This type of hardware, coupled with the new medical science that the Navy is seeking to harness, could provide fine-tuned control of the microbiome. Strange as it seems, gut microbiology may turn out to be the secret weapon of the supersoldiers of the future.
