Genetics influence Microbiome

The Microbiome is currently a very big topic and more and more connections between the microbes that colonize us and our well-being are being discovered. When we talk about the microbiome, we usually forget that the microbiome is only part of a very complex interplay. The composition of our microbiome is influenced by nutrition, lifestyle, early maternal transmission, immune status and genetics of each individual.

We are already very happy that the awareness to the microbes that live with us has found its way into research and slowly into general consciousness. Long enough we have maltreated these important fellow occupants with medication and hygiene.

However, it often seems that the microbiome alone is responsible for everything and that it can be manipulated at will in our favor.

A recent >>> study shows that it is not so easy after all. According to this study, genetics in connection with our microbiome plays a greater role than assumed and also has an influence on which microbes settle on us. In this study, the research group investigated the extent to which environmental circumstances influence the development of the microbiome in newborn mice. This includes vaginal inoculation with bacteria by the mother during birth.

Experiments with mice show no differences

In the experiments genetically different mice were crossed to generate genetically identical offspring. The microbes of the genetically different parents differed by about 20%, those of the offspring with identical genes differed by only 3%. One female and one male mouse of two different genetic origins were crossed with the other genetic part (illustrative: ♀A♂B and ♀B♂A -pairs). Thus, two groups of offspring emerged, which were genetically identical to each other, but had different mothers. Although the offspring were only kept together with the mother, their microbiome did not adapt to that of the mother.

It has to be said, however, that the data only refer to a small part of the bacterial composition of the respective microbiome, since all microbiomes were very similar to each other. In addition, despite the high microbial similarity of the offspring to each other, a small but negligible influence of the respective mother was seen. A larger study might show a more significant influence of the mother.

It's all in the station wagon

However, the conclusion of this study is that the genetic predisposition has a strong influence on the composition of our microbiome. The structure of the intestinal mucosa, different metabolisms (e.g. bile acid secretion), antimicrobial peptides or the tolerance of the immune system can control the microbial colonization of our body.

No permanent change of the microbiome possible?

These findings are not new, but are strengthened by this study. This explains why a microbiome cannot simply be permanently changed. Although it always adapts to the circumstances to a certain extent, it quickly returns to its original state as soon as the influences change again. Probiotics only have an effect as long as the probiotics are taken. A change in diet can change the balance of the microbiota, but it only remains in this state as long as the change in diet persists.

So it is, at least partially, in our hands which bacteria we give the upper hand to. However, the basis of our microbial colonization lies in our genes.