On Sunday, January 28th, the MSNH met at the American Museum of Natural History with Ph.D. candidate Melissa Ingala to hear more about what is “Inside You.” Ms. Ingala guided us, with great expertise and enthusiasm, through the exhibit of the same name. First, we learned that we are not alone – in fact, there are many more bacterial than human cells in and on each human body (in the human gut alone, there are about 100 Trillion bacteria!). While bacteria grow especially well on moist areas like your armpits, the left and the right hands do not have the same population of microbes. Not surprisingly, we share the same bacteria with co-inhabiting humans, but are also more likely to share them with our co-inhabiting canines, but not felines for yet to be understood reasons. “Of course not,” a cat owner whispered to me, with little surprise: “Cats share little with their owners.”
As bacteria and other microbes are found on most surfaces, scientists were able to show what most NYC citizens expected anyway: the subway system is full of interesting microbes, many of them which have not even been identified. No worries, we are safe – if anything, a subway ride might boost your immune system.
Microbes do not only vary among people, but they also vary among different populations. It appears that specific diets, like a diet high in seaweed as in Japanese, or like Sweet Potatoes as some tribes in Papua New Guinea, allow these people to turn these otherwise nutrient-poor food items into delicious, nutrient-rich morsels. Populations that are known to have a wide variety of food and rarely take antibiotics like the Yanomarni of the Amazonian Rainforest in Venezuela have an extremely diverse gut microbiome. Meanwhile, Europeans and Americans, possibly due to the overly sterile approaches towards life, paired with a reduced diversity in food, have the least diverse gut microbiome so far tested. Time to mix up your diet!
Melissa then talked about her research which focuses on true food specialists: vampire bats and fruit bats. These two groups have a very narrow range diet, none of which is known to provide enough macronutrients like protein. Melissa suspects that either their gut bacteria are creating the lacking macronutrients from scratch, or that at least the fruit bats consume a nibble of something else here and there to compensate for the lack of nutrients. Hopefully we will know more about it soon!
After that, Melissa led us into the world of health. This sparked a lot of questions. Some bacteria living in and on us are protecting us from other, more harmful bacteria and fungi like Athlete’s foot that would enter our system otherwise. The rise of inflammatory diseases might have been caused at least partially by the reduced diversity of our microbiome. Even diseases like obesity, depression, and anxiety might be affected by our bacteria, or may in turn affect them. But no worries – treatment is on the way! Fecal transplants (yes, it is exactly what you think it is) have been shown to reduce weight in otherwise obese mice (they received fecal samples from lean mice). Similarly, bacteria found in fermented foods like yogurt and sauerkraut might reduce anxiety in the same rodent. It appears that new medicines may require us to be less squeamish.
Thank you, Melissa for showing us the latest in this intriguing world, we hope to hear more about your research on bats and can’t wait to have you back again.
To view more photos from this event, visit our gallery. All photo credit goes to Glenn Doherty.
Melissa Ingala is a Ph.D. candidate in comparative biology at the Richard Gilder Graduate School at the American Museum of History. She is a New Jersey native who holds a masters degree in ecology and systematics from Fordham University. Her research interests concern the functional importance of the gut microbiome in wildlife hosts, and the roles microbes have played in the ecology and evolution of those hosts. She works closely with the Mammalogy and Genomics departments at the American Museum of Natural History, and has conducted field expeditions in the rainforests of Belize with AMNH curator Nancy Simmons.
Additional Resources recommended by Melissa Ingala
How Gut Bacteria Tell Their Hosts What to Eat from Scientific American