Last night, I headed down to the scintillating Symphony Space on Manhattan's Upper West Side, for the latest Secret Science Club North lecture. Last night's lecture marked the third appearance of microbiologist and medical doctor Martin J. Blaser, Director of the Human Microbiome Program at the NYU School of Medicine and author of the book Missing Microbes: How the Overuse of Antibiotics Is Fueling Our Modern Plagues.
The first lecture by Dr Blaser that I attended concerned the human microbiome, with a focus on the role that the bacterium H. pylori plays in the gastrointestinal tract. The second lecture was a more generalized overview of the role of the microbiome on health, touching on such topics as the possible role played by antibiotic overuse/misuse in the world's growing obesity epidemic- it corresponded with the initial release of Dr Blaser's book.
Last night's lecture could be characterized to a 'greatest hits' compilation- it was a broad overview of the subject of the human microbiome and the role that antibiotics play in the relationship between us and our bacterial symbionts. Much of the talk revolved around the findings of the graduate students in Dr Blaser's lab.
The human gut is home to over one hundred trillion bacteria, most of which are harmless or even beneficial to us. Recently, the overuse of antibiotics, much of which can be attributed to the use of sub-therapeutic levels of antibiotics to promote growth of farm animals, has adversely effected our internal biome, resulting in lower internal biodiversity among residents of the developed world. Dr Blaser displayed an array of gorgeous graphics to illustrate the relative biodiversity among the Venezuelan Yanomami, residents of Malawi, and residents of the developed world, with the Yanomami, who currently have little contact with outsiders, having a very high degree of internal biodiversity.
Dr Blaser noted that most of a newborn's microbiome is inherited from its mother, largely through vaginal birth, but also through close contact as breast-feeding, kissing, and in the case of some cultures, pre-mastication of food by mom. Babies born through C-sections tend to have less-developed gut bacteria than those born vaginally. By the age of three, an individual's gut microbiome is similar to that of an adult of the same cultural group.
Much of the lecture was involved with discussions of the role of antibiotic use in weight gain and possibly the onset of type 2 diabetes. While most of the experiments with mice involved sub-therapeutic levels administered over time, other studies mimicked the way in which people generally use antibiotics- pulses of high antibiotic use given to combat infection. Dr Blaser likened this to giving the mice antibiotics the same way parents would give antibiotics to a child with an ear infection. The 'pulsed' use of antibiotics early in life resulted in similar outcomes as the use of sub-therapeutic levels of antibiotics.
Dr Blaser made sure to note that the development of antibiotics was a civilization-altering occurrence, and that the use of antibiotics has hugely benefited humanity. The study of the relationship between individuals and their bacterial symbionts is a relatively new field, and Dr Blaser and his team are on the cutting edge of it. Dr Blaser jokingly told an anecdote about he and his staff sending stool samples off to have genetic testing of the microbiota performed, and not knowing exactly how to interpret the results. Our internal symbionts have evolved with us over the course of millions of years, but our relationship is just beginning to be parsed out.
Dr Blaser devoted a significant portion of his lecture to the work of his colleges and students, presenting their achievements in succession with a palpable sense of pride. For a talk about germs and poop, there was a genuine sense of joy about the topic.
Dr Blaser devoted a considerable amount of time to a Q&A session- he knows that there is an intense public interest in his research and its health implications. There were a lot of questions about probiotics and ways in which to 'reboot' (perhaps re-butt) one's internal biota after a course of antibiotics. The topic of fecal transplants came up, with one wag in the audience (of whom I am jealous) referring to them as trans-poo-sions. One bastard in the audience asked if anyone had done research concerning the effect of antibiotic use on the onset of menarche, but Dr Blaser noted that lower ages for the onset of puberty predated the development of antibiotics by about a century, and should be attributed to overall improvements in nutrition.
All told, the lecture was wonderful- entertaining as well as informative. Dr Blaser has a remarkable knack for making his subject matter accessible for the layperson, something crucial when it comes to a topic as intimate as one's relationship with one's one trillion closest friends. Kudos to the good doctor, Margaret and Dorian, and the staff of Symphony Space... once again, the SSC has knocked it out of the park.
Here's a video of Dr Blaser lecturing on this topic at the American Society for Microbiology:
Crack open a beverage and soak in that Secret Science Club ambiance.