I found a new article[i] yesterday on the mycobiome (yeast). To sum it up – we know next-to-nothing about what comprises a healthy one. 🙂
There were a few very interesting items in it that deserve mention:
- I already knew that there were differences in the bacterial microbiome between babies fed formula versus breast-fed, in large part because of the prebiotic elements (the oligosaccharides) and immune proteins found in breast milk Breast-fed babies have more beneficial bacteria including Bifidobacteria and Lactobacill Interestingly, in vitro studies show that these prebiotics also impact the virulence of yeast infections, preventing Candida (C.albicans) from invading intestinal epithelial cells. This has yet to be studied in actual humans yet, however.
- Antibiotics do not only affect the bacterial microbiome, but the mycobiome as well. One longitudinal study over the first 3 years of life showed that antibiotics cause an immediate change in the bacteria of the intestine, and while they do not directly affect the fungi, their use results in “…increased rates of fungal colonization, fungal overgrowth and changes in fungal community…” (Any woman who has developed a vaginal yeast infection after a course of antibiotics is only too familiar with this phenomenon.) It was the proposed mechanisms of action that I found interesting, including the fact that bacteria actually produce anti-fungal molecules. Killing them off then allows more fungi to grow.
- And vice versa: “…fungi affect bacterial colonization is also true,” as studies in which animals are colonized with candida show an altered bacterial repopulation.
- Thus, just like we know the macrobiome (helminths) and microbiome have a bi-directional relationship, so does the bacterial microbiome and the mycobiome. (It’s probably safe to assume then that since the presence of helminths positively affects the bacterial microbiome, their presence would also help keep fungal overgrowth in check. I do wonder if there’s not also a direct relationship…but that research is probably decades away.)
- The fecal mycobiomes of obese versus lean children and adults differ. Administration of Saccromyces boulardii (a probiotic yeast) has been shown to reduce obesity in humans and animals.
- It looks like the fungi of the intestines play a role in the development or prevention of allergy. I wonder then if this isn’t part of the reason that antibiotics given in the first two years of life is highly associated with allergies later on.
- There is a clear fungal signature in pediatric patients who develop inflammatory bowel disease. Whether or not this is a cause or effect of the diseases is not yet known.
Considering how all these biomes work together as a whole, I have to believe that improving the quality of the bacterial microbiome and supplementing a macrobiome would lead to an improved mycobiome.
In the autism community, antifungals are often used for years at a time. While a minority of children are positively affected, it is still a large number, and there was always some question about why they worked. Reading this, I have to believe that it’s not just the direct effect of potentially reducing yeast overgrowth in these immune compromised children but also, the indirect effect on the bacterial microbiome, which we know for certain is a part of the disorder.
[i] Ward, TL, Knights, D, Gale, CA. Infant fungal communities: current knowledge and research opportunities. BMC Medicine. 2017:15:30.