A Gut Feeling-Judging Information on the Human Gut Microbiome

Oct. 14, 2016

What’s your gut feeling on microbiome research?  It seems like nearly every day a new connection between the human gut microbiome and a feature of our health is learned. While the advancements are exciting we need to balance enthusiasm with patience to avoid the spread of misconceptions.

Wild garden of the gut bacteriaFigure 1. The Wild Garden of the Gut-a piece of Agar Art created with bacteria found in the gut (E. coli, Citrobacter, and Klebsiella) by Dr Nicola Fawcett. Source.

Two weeks ago, I mentioned my visit to the Santa Barbara Fermentation Festival where locals not only shared delicious brews and recipes for other fermented foods, they discussed the human gut microbiome and its relation to our health and the foods we eat.  What this experience demonstrated is that many people are curious to know more about their microbiomes and that researchers need to engage this inquisitive public to ensure correct information is disseminated.  Events like the Fermentation Festival are a great opportunity to do this as attendees are eager to learn and ready to engage with experts willing to share their time and expertise.  Moreover, it is critical to take advantage of these opportunities to help curb the flow of misinformation regarding what is actually known about the human gut microbiome.  It doesn’t take much searching online to find wild claims by advertisers of products and self-proclaimed experts alike, promising the holy grail of a gut microflora that will cure whatever ails you.  If only such a thing were possible!  The problem with these misconceptions is that they can lead to dangerous practices such as the abandonment of data-supported treatments in favor of unverified approaches and use of potentially dangerous home remedies.

At the festival, the main points of public interest fell into one of three main categories: probiotics, leaky gut, and the influence of the gut microbiome on diseases.  For probiotics, participants wanted to know which on the market were most effective.  Although one of the speakers pointed out that any probiotic taken would have to be capable of surviving the harsh conditions of the stomach and thriving in the intestines before conferring any benefit to the host, potential conflicts of interest and the importance of supporting evidence from peer-reviewed literature were not discussed.  Many of the presenting experts were also exhibitors selling microbiome-related products, and references to published studies were entirely lacking.  While relationships have been indicated through various studies, research has not pointed definitively at specific microbes that should be consumed for improved health.  Given the complexity of the gut microbiome and the diversity across humans, the only safe bet is to say that we’re a long way off from a therapy or treatment-ready understanding of the gut microbiome.

Figure 2-Gut FeelingFigure 2. Festival-goers at the Santa Barbara Fermentation Festival listening panelists talk about the human gut microbiome. Photo Credit: Steven Goins.

Discussions of “leaky” gut syndrome and the potential connection with the gut microbiome to a wide range of diseases also took front stage at the Fermentation Festival talks.  If you’re not familiar with the term leaky gut - a.k.a. intestinal barrier dysfunction or disruption - it describes the phenomenon of the typically tight connections between intestinal cells weakening to the point of permitting microbes and large molecules out of the intestinal tract and into the surrounding tissue and blood vessels, where they cause damage and disease.  While this phenomenon does occur, it has been readily ascribed to conditions without sufficient evidence.  Here, it isn’t simply of a matter of pointing individuals towards literature; a range of publications can be found that warrant a further discussion on research quality.  The same can be said of diseases now attributed to “unhealthy” microbiomes, thanks to the tendencies to confuse correlation with causation and to interpret anecdotal stories as hard scientific evidence.  It can be difficult to manage the numerous claims of news and journal articles alike, balancing them against what has likely become a mantra for serious microbiome researchers:  “it’s simply too soon to tell, more work needs to be done.”  While we are likely to uncover more about the relationships between the gut microbiome and diseases in our continued efforts to unravel the mysteries of our gut microflora, we must be patient (and counsel that in others).

Human figure showing arteries and viscera Persian 18th C Wellcome L0031822Figure 3. Human figure showing arteries and viscera, Persian, 18th C. Source.

But what do we do in the meantime to manage the information thrown at us?  And how do we manage the curiosity of the public at large, which is eager for answers, and not eager for complex explanations?  As noted above, it’s critical to take action and engage with those who want to learn more about the human microbiomes, and this means being aware of the misconceptions held.  However, not all of us are experts on the human microbiome and it simply isn’t possible to be aware of all the current literature published on it.  But don’t fret, go with your gut!  Walk yourself and the interested souls around you through the basic questions you ask yourself all the time without realizing.  Who is saying this?—Are there any potential conflicts of interest such as ties to a company that stands to make a profit off the claims?  What backs up this claim?—Peer reviewed research in a well-respected journal or anecdotes on a website?  If the anecdotes are true the data will back them up, so there is no reason to fear the scientific literature.  What does the evidence really say?—Causation or simply correlation?  (Here’s a great reference to handle that conversation.)  And finally, is this too good (or simple) to be true?  We like our answers short and to the point, but the diversity of microbiomes combined with the uniqueness of humans means that little of what we learn will be all-encompassing.  This complexity isn’t a bad thing though.  We discussed last week that there is the potential for personalized medicine up ahead with microbiome research.  An exciting prospect!  And to help us along the way, there is also the American Gut Project, a means through which the curious citizen may contribute part of themselves directly to microbiome research and help scientists gain a better picture of the relationship between host and microbiome.  Bringing the public into the research process not only helps with the gathering of data, it helps to break down the perceived barrier between citizen and scientist and build trust, a much needed element when communicating about science.  And suggesting someone send a fecal sample through the mail is bound to turn into an amusing conversation for all involved, even if that “person” is actually a bear.

Further Reading

American Society for Microbiology. (2013) FAQ Human Microbiome.

Wang J. & Jia H. (2016) Metagenome-wide Association Studies: Fine-mining the Microbiome. Nature Reviews Microbiology, 14, 508-522.


Author: Janet Goins

Janet Goins
Dr. Janet Goins is Assistant Director of UCLA's Undergraduate Research Center. She provides undergraduate students with research experiences that prepare them for future success in STEM-related careers. Previously, her research focused on the ecological impacts of algal host-virus interactions, the evolution of and molecular steps involved in host cell pathogen defense, and the biological factors that influence harmful algal blooms.