The Glory of Gut Flora: These Amazonian Peoples Have Ten Times Our Biodiversity

The Yanomami tribe has had almost no contact with other civilizations for over 11, 000 years.  In 2008, they were accidentally spotted through a clearing in the Venezuelan Amazon.  They've stayed mostly isolated, for very good reasons, but have allowed local researchers to come and take samples of soil and bodily fluids.  It's as good a shot as any at pinning down a picture of the original human gut. 

From the CBC: The Yanomami of the Venezuelan Amazon.  People aren't totally sure where the t-shirts came from. 

From the CBC: The Yanomami of the Venezuelan Amazon.  People aren't totally sure where the t-shirts came from. 

In medicine, we consider the lining of the mouth, down through the esophagus, stomach, small bowel, colon, rectum and anus to be totally continuous with the external environment. 

What happens in my gut is a reflection of the mini-suite of local bugs that surround me in the air, water, soil and food.  

It is ok to geek out about this.  This is very cool stuff. 

The modern gut is pretty spic-and-span.  We brush and floss.  The Yanomami don't.  We don't really eat food with dirt on it anymore, unless you have a veggie box delivery or shop at a Farmer's Market.  The Yanomami are their own farmer's market.  We scrub and sterilize everything.  The Yanomami don't. And we get antibiotics, even when we don't need'em. The Yanomami don't.  But if contact continues, they might be in trouble.  

It's safe to say that our gut microbiome isn't really the same as that of our grandparents, or the many generations before.  But, is that a good thing?  Rates of hypersensitivity, autoimmune and inflammatory conditions are much higher than ever before and it's possible that some of that is because we didn't know about a number of conditions as little as 25 years ago.  But it also seems like we just have new diseases around that probably reflect a combination of our environment, our genes and the interaction of our genes with the environment. 

As for the Yanomami, one of the research team members spoke with The Current's Anna Maria Tremonti in April about the key findings.  The Yanomami gut bacterial universe is twice as diverse as yours or mine.  Even more, some of the gut bacteria demonstrate antibacterial resistance.  To explain that idea, imagine that a Yanomami person has regular bacteria hanging out in their gut.  Over time, the bacteria gets insulted by their diet or a change in the environment.  In order to survive, it has to mutate so that, in the future, it can survive the next insult.  It becomes a superbug.  The researchers suspect that these superbug mutations come from the soil because the soil flora had the same genes for antibacterial resistance. 

 Over in North America, the research on gut flora is reaching a total fever pitch.  The Journal of the American Medical Association just released a run down of the lab science so far behind the idea that our gut flora affects our mood in a direct, measurable way.  Using mice, researchers introduced various strains of bacteria and monitored mice for anxious behaviours and the results, which started piling in in 2004, have been quite spectacular.  Humans are up next for trials. 

JAMA May 5, 2015, Vol 313, No. 17 Unraveling the Influence of Gut Microbes on the Mind

JAMA May 5, 2015, Vol 313, No. 17 Unraveling the Influence of Gut Microbes on the Mind

What I know for sure is that the way antibiotics make it from the natural world to the pharmacies is getting more and more complicated.  And also that treating super-infections in very sick people in hospitals is more and more a game of risk that few are excited to play. 

The way I've been taught to prescribe antibiotics over the past three years is going to change.  Patients have to start changing their minds about wanting an antibiotic "just to be on the safe side" because antibiotics are not benign. 

The most logical next question? Probiotics!

Our Monday Muster this week will look at what we know about probiotics and how the landscape may be shifting given what we know about the gut-brain connection.