The Microbiome: An interview with Dr. Jack Gilbert

Dr. Gilbert is a Principal Investigator (Environmental Microbiologist) at Argonne National Laboratory and a Fellow at the Marine Biological Laboratory, both affiliated with the University of Chicago in Chicago, Illinois, where he also holds the position of Assistant Professor. His research interests include include the temporal and biogeographic structure of microbial communities, the taxonomic diversity of marine microbial communities, and the metabolic dynamics of microbial communities. He is leading the Microbiome segment of research for The Longest Swim.

The bodies of extreme endurance athletes like ultra-marathon runners (or trans-Pacific swimmers!) undergo many changes during and after competition. Since digestion is not a priority during strenuous exercise, blood can be shunted away from the gastrointestinal tract; however this can cause problems like abdominal cramps and diarrhea when athletes have to fuel up along the way. This kind of distress can alter the body’s natural bacterial flora, also called the microbiome. To measure the changes to Ben’s microbiome the crew will take periodic samples from all over his body, including the surface of his skin to see how his body interacts with the marine bacteria it encounters.

What does your research focus on?

Our research focuses on the microbiome and how it will sustain Ben Lecomte over the course of his swim across the Pacific Ocean. Given his timeline, he needs to swim on average about 25 miles per day. If you look at exertion rates, this is equivalent to running an ultra-marathon every day considering swimming exerts four times the effort as running. If you take into account his age and fitness level, Ben needs to consume about 10K calories per day, which is physically unattainable. The question becomes how will his body adapt over the course of the journey, and how will microorganisms that regulate inflammation, metabolism, and even behavior respond to such drastic changes.

What kind of changes does the human microbiome undergo during or after strenuous exercise?

First and foremost, I expect Ben’s microbiome to be completely shifted by the end of his journey. I’m expecting bacteria that was once dominant to be in very low abundance by the end, and vice versa for low abundance organisms due to continued distress and disturbances placed on the body. I’m also expecting extremely high levels of inflammation simply due to increasing caloric deficits and stress due to physical activity. Lastly, I’m expecting his primary energy source to be his fat storage, muscle mass and even bone density. I believe his microflora will need to make some serious adaptations.

And what about the marine bacteria Ben will encounter- have those interactions ever been studied like this before?

Because we are well aware that human microbiome is strongly shaped by its environment. I’m expecting the microflora found in the ocean to be heavily represented on Ben’s skin and in his gut. Now the role it takes on isn’t very clear considering no one has spent this much time in the water. We can look at studies involving swimmers and get an idea, but it has never been this extreme.

Will what you learn from The Longest Swim help athletes here on land?

We will get a better sense of what governs inflammation and metabolism, which is cornerstone in sports. Being big, fast, and strong is only one component to athlete success, but maintaining these outputs become more vital than the former. Ben Lecomte’s journey is going to provide a lot of insights not only in physical activity maintenance of physical activity as well.

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