Media release

From: Springer Nature

Human microbiome statements lack evidence

Human microbiome literature contains inaccuracies that lack a solid evidence base, argue Alan Walker and Lesley Hoyles in a Perspective article in Nature Microbiology. They highlight persistent or emerging myths and misconceptions about the human microbiome and outline their factual inaccuracies.

There has been an explosion of research and public interest in the human gut microbiota, especially on the links between these complex microbial communities and health and disease. This increase in interest has also led to hype and has entrenched some misconceptions. Statements on this topic can be repeated so they become considered facts, without strong supporting evidence and with ambiguity regarding the original source.

Alan Walker and Lesley Hoyles call attention to 12 illustrative examples of myths or misconceptions prevalent in the human microbiome literature. The myths include the idea that the research field is new, when the first research into human-associated microorganisms actually occurred hundreds of years ago, and also include the belief that Joshua Lederberg coined the term ‘microbiome’. The authors highlight the oft-repeated statement that “the microbiota outnumbers human cells by 10:1”, which others have shown to have originated from a 'back of the envelope' calculation in the 1970s, when in fact the ratio is closer to 1:1. They note other beliefs that have potentially more serious implications for future research, including the unsupported idea that we are unable to grow most of our gut microorganisms in the lab, and uncritical repetition of preliminary microbiota-disease associations that have not been subsequently replicated in follow up studies.

The authors argue that raising awareness of myths and misconceptions, even if relatively minor, is important to avoid unproductive research projects, to encourage critical thinking and to preserve public confidence in microbiome science.