Evidence for the impact of intestinal flora on metabolic processes is increasing. The balance of intestinal flora may be altered following antibiotic use, perhaps for prolonged periods. Antibiotic use is increasing, and by some accounts, rates of Autism Spectrum Disorders is also increasing. Perhaps factors secreted by intestinal bacteria can influence fetal brain development. One way to look at this might be to prospectively culture the stool of a cohort of women planning to get pregnant, and correlating biome parameters with occurrence of ASD. Another might be to mine the data of large health care organizations looking for pre-conception maternal antibiotic use and correlate with ASD in offspring. Is anyone looking at these possibilities?
Current research suggests that brain changes in autism begin prenatally, therefore the flora present pre-conception would have a larger impact on brain development than the flora acquired after birth. A mother who had a typically developing child, then had a course of antibiotics for, say, a bladder infection, might have a very different microbiome when gestating a subsequent child.
Thank you for this. I had not realized until now the new work identifying the amniotic fluid and placental microbiome, which is replacing the old paradigm of the sterile fetus. I am continually in awe of the intricate collaboration which is the ecology of our body, saddened by the way we so casually clear-cut it with antibiotics, and hopeful as we begin to understand more. The question now becomes more complex: could antibiotic use affect the maternal, placental or amniotic fluid microbiome, leading to the elaboration by these microorganisms of factors that might adversely affect fetal brain development?
The issue is, indeed, exceedingly complex. Many factors, in addition to antibiotics, can affect the microbiome, including stress, diet, external environment, and illness. It is undeniable that antibiotics will significantly affect the microbiome, but illness, also affects fetal development. Given the impact of group B strep on neonatal outcome, for example, or of sexually transmitted diseases such as gonorrhea or chlamidia, I might hesitate to too quickly condemn antibiotic use in pregnancy. In addition, although the microbiome may, indeed, affect epigenetics, exactly how, and through which components of the biome would need to be elucidated.
See http://www.sciencedirect.com/science/article/pii/S1438422114000587 for an example of one study that looks at a different stage of life, i.e., SIDS in infancy, and it is apparent that we are in the infancy of understanding these complex environmental interactions, and certainly not at a stage to do active intervention.
I agree with you, Dr. Babcock. We are just at the very beginning of the exploration. The metaphor of antibiotic use as a form of clear-cutting was a philosophical lament, not a recommendation. On the other hand, given that, for example, fecal transplants have succeeded in treating c. dif. colitis, caused by, and often worsened by, antibiotic use, I see hope for a possible expansion of our worldview. Perhaps if we do find a relation between the biome and autism, or any clinical problem, our therapeutic choices may be broadened beyond simply antibiotics vs no antibiotics, in the same way that our assessment of forests is beginning to go beyond the measure of board-feet.
Yes, it is a very challenging area of research, as is the area of modifyin epigenetic changes that may impact disease. Who knows what the future holds. A decade ago we probably thought it would take decades to unravel the genome, but we are everyday able to analyze larger and larger volumes of data. If we consider the microbiome has vastly more DNA sequences that our own genome, it will be a challenge to identify and isolate potential targets and potential mechanisms by which these targets affect disease processes or human development. But there is no reason to presume the task is beyond our abiities to address. And we have to start somewhere.
Yes, I agree with you, Dr. Babcock. I believe in fact that our survival as a species depends on our ability to live harmoniously with life forms both within and around us, and learning more about all of our genomes will have an important role in this process. We live in an exciting time.
I'm glad you brought up the point that many of these (who knows, maybe most of these) microbiome component organisms are commensal or symbiotic. An interesting question can also be how these organisms can reestablish their place when they are disrubted or displaced.
I think this question is right on point. I think that in biological systems reciprocity evolves in parallel with diversity, whether the system is large, like a forest or coral reef, or smaller, like a person’s body.
In biological systems this reciprocity would be called health, in social systems, trust. I think that a great many of our biological and social problems can be traced to a loss of diversity and resulting gaps in systems of reciprocity. The use of probiotics, fecal transplants, and fermented foods represent early, exploratory steps to reestablishing diversity.
- Badges
- Science topic
- Similar topics
- Geoscience
- Asia
- India