Microbes within the colon located in the top left corner separated from colon cells (bottom right corner) by a layer of mucus (diagonal green across the image). Credit: Kristen Earle, Gabriel Billings, KC Huang, Justin Sonnenburg
This weekend I followed up with Erica Sonnenburg, PhD, senior research scientist at Stanford University School of Medicine in the Department of Microbiology and Immunology, (also author of The Good Gut). Erica presented at a salon, Understanding the Microbiome, in April 2017, which is available on our Youtube channel. I was curious to learn more about the microbiome.
How do fermented foods survive passage through the acidic environment of the stomach?
While many microbes are killed by the acidic environment of the stomach, many actually make it through alive, by being buried in other food that's being digested or other means. However, the acidic environment of the stomach is not fool-proof which is how pathogenic bacteria get through to cause food poisoning. Since we are born largely without microbes in the gut, many of these microbes originally colonize us by passing through the stomach.
If one has a bowel prep, how does that affect the microbiome?
A bowel prep does affect the microbiota quite profoundly, but it looks like the community is able to recover after about 2 weeks, so it does exhibit some incredible resilience.
If one were to alter their diet after a bowel prep, would their microbiota change forever?
That's tough to answer since it hasn't been tried, but my guess is that it would still mostly go back to where it started. It seems like long-term dietary change is key, so if they changed their diet permanently it would ultimately change but it's not clear that the bowel prep would have even been important in that case.
How does a fecal transplant ultimately affect one's microbiome? Does the transplanted person acquire the microbiome of the donor?
A fecal transplant can also affect the microbiota profoundly. Amazingly, the microbiota of the person after receiving the fecal transplant has about 1/3 of the microbes from their original microbiota, 1/3 of the microbes from the donor microbiota, and 1/3 of the microbes from somewhere else. It is not clear where the "somewhere else" microbes are coming from.
Erica Sonnenburg, PhD
Erica Sonnenburg, PhD, is a senior research scientist at the Stanford University School of Medicine in the Department of Microbiology and Immunology where she studies the role of diet on the human intestinal microbiota. She has published her ground breaking scientific findings related to the microbiota in prestigious journals such as The Proceedings of the National Academy of Sciences, Cell, and, Nature.
She is the co-author, along with Justin Sonnenburg, of the book The Good Gut: Taking Control of Your Weight, Your Mood, and Your Long-Term Health.
Erica has two school-aged daughters. In her free time she enjoys gardening and cooking for her family and their trillions of microbes!