Speculations About Artificial Womb Technology
Ideas about how humans and other animals interact with the microbial world are undergoing some big revisions. Multiple lines of evidence reveal an organism’s microbiome does far more than promote food digestion, but is an essential – and extensive – symbiosis. Investigators are now tracing the multifaceted interactions between host and microbial flora that affect development, organ structure and perhaps behavior (1). The internal and external surfaces of animals are unique, environmentally sensitive ecosystems. One of the more radical ideas to come forth recently is that humans might acquire billions of bacterial viruses (bacteriophages) from food and water daily (2). This interplay has unknown consequences for both the resident bacterial flora and the host.
Are We Ever Sterile?
The bacterial flora of humans changes with chronological age and responds to environmental inputs. A general belief that the womb was normally sterile led to the assumption that the colonization processes only began with passage through the birth canal. New findings suggest that the charter members of our microbial teams might take their places during gestation as bacteria are passed from mother to the developing child (3).
The hypothesis human microbial communities are founded before birth is controversial because the direct experimental evidence is equivocal (3). Does the existence of germ-free (gnotobiotic) animals rule out the gestational establishment model? It does complicate the idea, but this objection may conflate two rather distinct situations. Observations suggest the interplay between microbial ecosystems and host could be much more dynamic than suspected previously (2). Further, transient bacteremia – bacteria in the blood – is common in persons of normal health; temporary surges of microbes in the circulatory system follow activities such as tooth brushing. Could transient invasions play a role in fetal development or the training/priming of the forming immune system? We know some pathogens are adept invaders and able to persist within host cells for decades. Could communities be established in utero by hardy pioneer microbes that are difficult to culture or present in low numbers?
The Hygiene Hypothesis
Another idea that has gained currency recently is that our modern era quest toward cleanliness and wide use of antibiotics has backfired. Taking sanitation of our surroundings and ourselves too far has impeded our innate defenses by antagonizing the normal microbial communities needed to train and maintain our immune systems (4). The results may have been upsurges in autoimmune diseases like asthma, food poisoning susceptibility and perhaps obesity (4). The hygiene hypothesis is an economical way to account for the rise of allergies and degenerative diseases. However, it is important to recognize many factors have changed over the last decades including diet, life styles and exposures to chemicals such as antibiotics. That makes it hard to decide which is(are) a preeminent or even a significant influence on overall health status.
Meet You at the Crossroads – Reproductive Cloning, Mammophants and Artificial Wombs
The announcement the reproductive cloning of nonhuman primates has been achieved reminds us that this basic strategy has succeeded with a number of animal species (5). Scientists are speculating that a confluence of advances might turn fanciful dreams like resurrection cloning of extinct species such as the woolly mammoth into reality (6). Developments in artificial womb technology – ectogenesis – may be a key facet in furthering such work and more (6, 7).
We are rapidly approaching a point where the traditional norms and strictures of biomedical research with embryos and ectogenesis technology will be splintered (The Rules No Longer Apply ). How well will efforts like resurrection cloning mammophants, the term coined to describe these strange hybrid beasts with no natural progenitor kin, succeed (6)? In one sense, if it all works, it will be eerily reminiscent of the Frankenstein tale written by Mary Shelley two centuries ago. But, could it be that artificial wombs will just plain turn out to be too sterile? Might those who would breathe new life into extinct creatures through ectogenesis technology fall victim to an unforeseen issue? Perhaps the uterine hygiene hypothesis will be confirmed if and when the unleashed beasts from artificial wombs have immune dysfunction or other developmental issues. Instead of being an ingenious solution to tundra melting the first resurrected mammophants might be the animal equivalents of hot house flowers that just do not do well in nature.
It will be interesting to see how our technological dreams play out in the real world.
(1) Sarah C. P. Williams. Gnotobiotics. Proceedings of the National Academy of Sciences of the United States of America. 111(5):1661.
(2) Giorgia Guglielmi. Does a Sea of Viruses Inside Our Body Keep Us Healthy? Science, 21 November 2017. http://www.sciencemag.org/news/2017/11/does-sea-viruses-inside-our-body-help-keep-us-healthy
(3) Cassandra Willyard. Could Baby’s First Bacteria Take Root Before Birth? Nature, 17 January 2018. https://www.nature.com/articles/d41586-018-00664-8
(4) Kate Murphy. Invite Some Germs to Dinner. The New York Times, 9 May 2015. https://www.nytimes.com/2015/05/10/sunday-review/invite-some-germs-to-dinner.html
(5) Gina Kolata. Yes, They’ve Cloned Monkeys in China. That Doesn’t Mean You’re Next. The New York Times, 24 January 2018. https://nyti.ms/2FbC6KY
(6) Hannah Devlin. Woolly Mammoth on Verge of Resurrection, Scientists Reveal. The Guardian, 16 February 2017. https://www.theguardian.com/science/2017/feb/16/woolly-mammoth-resurrection-scientists
(7) David Warmflash. Artificial Wombs: The Coming Era of Motherless Births? Genetic Literacy Project, 12 June 2015. https://geneticliteracyproject.org/2015/06/12/artificial-wombs-the-coming-era-of-motherless-births/