Bacteria are very very rarely bad or good

A reader messaged me this

hello I do not want to bother, I have a question in the laboratories of my country, in the microbiota tests they put veillonella as virulent, but in a recent publication of microbiome prescription I saw that it could be a solution, why do the laboratories attribute virulence to it?

My Answer

That is equivalent to saying “Italians are criminals”. Why would someone say that? “Some Italians belong to the Mafia”

Veillonella is a genus of gram-negative, anaerobic bacteria that are commonly found in the human oral cavity, gastrointestinal tract, and respiratory tract. While some strains of Veillonella can cause infections, particularly in individuals with compromised immune systems, the majority of strains are considered to be non-virulent or opportunistic pathogens. Some studies have suggested that Veillonella may play a role in certain disease states, such as periodontal disease, but more research is needed to fully understand the potential pathogenic mechanisms of this genus.


For a lab to creditably state that, the lab would need to identify the specific strain. Veillonella is a genus, composed of many species, each species is composed of many strains. In terms of our Italian allergy, Italians come from many regions of Italy (species), within each regions are many families (strains). There may be some of these families that tend to being Mafia, others may tend to be priests (and eventually Popes).


My attitude is that Yin and yang is a better way of viewing bacteria. Bacteria are out of balance. Too many poor people results in high crime rates (out of desperation), Too many rich people results in low class mobility (the only people that get ahead are their friends, “old school ties”). The “right balance” for a well functioning society varies by country — for example, Iceland versus Haiti. Similarly, your DNA and diet influences what the right balance should be.

This family’s favorite and most effective probiotic is Mutaflor, an Escherichia coli probiotic. All E.Coli is not bad, trying to eliminate all E.Coli is likely a very dumb choice.