Natures wonders: Mothers passing microbiomes (Introduction)

by David Turell , Wednesday, July 26, 2023, 19:05 (276 days ago) @ David Turell

Present in all species, but method different in one:

https://www.sciencedaily.com/releases/2023/07/230724122702.htm

"Caecilians are an elusive type of amphibian that primarily live underground and look like a cross between a worm and a snake. One of the few things that is known about caecilians is their unique method for feeding their young. Mothers produce a special layer of fatty skin tissue, which juvenile caecilians tear off with baby teeth that evolved specifically for that purpose.

"A new study shows that skin-feeding does more than provide nutrients for young caecilians. It also helps the mother pass microbes from her skin and gut down to her young, inoculating them to jump-start a healthy microbiome. This is the first direct evidence that parental care in an amphibian plays a role in passing microbes from one generation to the next.

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"Across the animal kingdom, there are many different strategies for parental care. Human mothers give their babies breastmilk, emperor penguins regurgitate food for their chicks, and female koalas feed their young a special form of feces.

"Among amphibians, caecilians are unique for feeding their young at all. Previous efforts to understand amphibian microbiomes focused on frogs and salamanders, the more well-known orders of the Amphibia class. Those studies, however, came back inconclusive largely because there are few frog and salamander species that care for their young after they're born or hatched -- most simply lay eggs and leave them to develop on their own.

"Not so with caecilians.

"When you find the eggs, you always find the mother," said Marcel Talla Kouete, first author of the study and a doctoral candidate in the University of Florida School of Natural Resources and Environment. "I've never seen a juvenile without an attending mother."

"Kouete said this is why he became fascinated by caecilians as he began working on them. Since this parenting behavior first came to light in 2006, scientists have noticed that even once skin-feeding ends, mother and babies stay together, with the former coiling her body around the latter. Kouete wondered whether the behavior served another function in addition to providing nutrients, reasoning that there was likely some transfer of the microbes from the surface of the mother's skin, similar to bacterial transmission in other animals.

"In humans, microbes move onto the skin as babies pass through the mother's birth canal and into the body via breastmilk. These microbes help keep the human body alive and well, forming a microscopic community known as the microbiome, and perform essential tasks like breaking down complex carbohydrates, training the immune system and producing vitamins. A growing body of research seeks to better understand the relationship between disease and microbiome health.

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"Samples taken from the surrounding soil, water and leaves showed that the immediate environment was the least important source for juvenile microbiomes."

Comment: a new way to offer a microbiome. This article shows that almost all bacteria are here for good purposes. It answers theodicy complaints about terrible bacteria which are good unless entering the wrong places.