Jul 5th 2017

I spent three days as a hunter-gatherer to see if it would improve my gut health

by Tim Spector and Jeff Leach

Tim Spector, in the picture above right, is Professor of Genetic Epidemiology, King's College London Jeff Leach is Visiting Research Fellow, King's College London
File 20170629 29069 1yxvqga Jeff Leach, Author provided

Mounting evidence suggests that the richer and more diverse the community of microbes in your gut the lower your risk of disease. Diet is key to maintaining diversity and was strikingly demonstrated when an undergrad student went on a McDonald’s diet for ten days and after just four days experienced a significant drop in the number of beneficial microbes.

Similar results have been demonstrated in a number of larger human and animal studies.

Your gut microbiome is a vast community of trillions of bacteria that has a major influence on your metabolism, immune system and mood. These bacteria and fungi inhabit every nook and cranny of your gastrointestinal tract, with most of this 1kg to 2kg “microbe organ” sited in your colon (the main bit of your large intestine).

We tend to see the biggest diet-related shifts in microbes in people who are unhealthy with a low-diversity unstable microbiome. What we didn’t know is whether a healthy stable gut microbiome could be improved in just a few days. The chance to test this in an unusual way came when my colleague Jeff Leach invited me on a field trip to Tanzania, where he has been living and working among the Hadza, one of the last remaining hunter-gatherer groups in all of Africa.

Hadza hunters. Jeff Leach, Author provided

My microbiome is pretty healthy nowadays and, among the first hundred samples we tested as part of the MapMyGut project, I had the best gut diversity – our best overall measure of gut health, reflecting the number and richness of different species. High diversity is associated with a low risk of obesity and many diseases. The Hadza have a diversity that is one of the richest on the planet.

The research plan was devised by Jeff who suggested I should have an intensive three days of eating like a hunter gatherer during my stay at his research camp. I would measure my gut microbes before heading to Tanzania, during my stay with the Hadza, and after my return to the UK. I was also not allowed to wash or use alcohol swabs and I was expected to hunt and forage with the Hadza as much as possible – including coming in contact with the odd Hadza baby and baboon poo lying about.

To help us record the trip I was accompanied by Dan Saladino, the intrepid presenter and producer of BBC Radio 4’s The Food Programme, who was preparing a Hadza microbe special.

After a long tiring flight to Mount Kilimanjaro Airport in Tanzania, we stayed overnight in Arusha, a city in the north of the country. Before setting off the next morning, I produced my baseline poo sample.

After an eight-hour journey in a Land Rover over bumpy tracks, we arrived. Jeff beckoned us to the top of a huge rock to witness the most amazing sunset over Lake Eyasi. Here, within a stones throw of the famous fossil site of Olduvai Gorge and with the stunning plains of the Serengeti in the distance, Jeff explained that we were never going to be closer to home as a member of the genus Homo, than where we were standing at that moment.

The million-year-old diet

The Hadza seek out the same animals and plants that humans have hunted and gathered for millions of years. Importantly, the human-microbe tango that played out here for aeons probably shaped aspects of our immune system and made us who we are today. The significance of being in Hadza-land was not lost on me.

Unlike the Hadza, who sleep around the fire or in grass huts, I was given a tent and told to zip it up tight as there were scorpions and snakes about. I had to be careful where I stepped if I needed a nocturnal pee. After an interesting but restless night’s sleep, a large pile of baobab pods had been collected for my breakfast.

The baobab fruit is the staple of the Hadza diet, packed with vitamins, fat in the seeds, and, of course, significant amounts of fibre. We were surrounded by baobab trees stretching in the distance as far as I could see. Baobab fruit have a hard coconut-like shell that cracks easily to reveal a chalky flesh around a large, fat-rich seed. The high levels of vitamin C provided an unexpected citrus tang.

The Hadza mixed the chalky bits with water and whisked it vigorously for two to three minutes with a stick until it was a thick, milky porridge that was filtered – somewhat – into a mug for my breakfast. It was surprisingly pleasant and refreshing. As I wasn’t sure what else I would be eating on my first day, I drank two mugs and suddenly felt very full.

My next snacks were the wild berries on many of the trees surrounding the camp – the commonest were small Kongorobi berries. These refreshing and slightly sweet berries have 20 times the fibre and polyphenols compared with cultivated berries – powerful fuel for my gut microbiome. I had a late lunch of a few high-fibre tubers dug up with a sharp stick by the female foragers and tossed on the fire. These were more effort to eat - like tough, earthy celery. I didn’t go for seconds or feel hungry, probably because of my high-fibre breakfast. No one seemed concerned about dinner.

Hadza women lightly roasting starch and fibre-rich //ekwa tubers. Jeff Leach, Author provided

A few hours later we were asked to join a hunting party to track down porcupine – a rare delicacy. Even Jeff hadn’t tasted this creature in his four years of field work.

Two 20kg nocturnal porcupines had been tracked to their tunnel system in a termite mound. After several hours of digging and tunnelling – carefully avoiding the razor-sharp spines – two porcupines were eventually speared and thrown to the surface. A fire was lit. The spines, skin and valuable organs were expertly dissected and the heart, lung and liver cooked and eaten straight away.

Hadza hunter walking back to camp with a dispatched porcupine flung over his shoulder. Jeff Leach, Author provided

The rest of the fatty carcass was taken back to camp for communal eating. It tasted much like suckling pig. We had a similar menu the next two days, with the main dishes including hyrax – a strange furry guinea-pig-like hoofed animal, weighing about 4kg – a relative of the elephant, of all creatures.

Harvested high from a baobab tree, our dessert was the best golden orange honey I could ever imagine – with the bonus of honeycomb full of fat and protein from the larvae. The combination of fat and sugars made our dessert the most energy-dense food found anywhere in nature and may have competed with fire in terms of its evolutionary importance.

In Hadza-land nothing is wasted or killed unnecessarily, but they eat an amazing variety of plant and animal species (around 600, most of which are birds) compared with us in the West. My other lasting impression was how little time they spent getting food. It appeared as though it took just a few hours a day – as simple as going round a large supermarket. Any direction you walked there was food – above, on and below ground.

Massive increase in microbiome diversity

Twenty-four hours later Dan and I were back in London, him with his precious audio tapes and me with my cherished poo samples. After producing a few more, I sent them to the lab for testing.

The results showed clear differences between my starting sample and after three days of my forager diet. The good news was my gut microbal diversity increased a stunning 20%, including some totally novel African microbes, such as those of the phylum Synergistetes.

The bad news was, after a few days, my gut microbes had virtually returned to where they were before the trip. But we had learnt something important. However good your diet and gut health, it is not nearly as good as our ancestors’. Everyone should make the effort to improve their gut health by re-wilding their diet and lifestyle. Being more adventurous in your normal cuisine plus reconnecting with nature and its associated microbial life, may be what we all need.


This article was originally published on The Conversation. Read the original article.

Browse articles by author

More Essays

Jul 4th 2020
EXTRACT: "--- Nobody is more dangerous than he who imagines himself pure in heart, for his purity, by definition, is unassailable. --- Author James Baldwin’s words, written in the America of the late 1950s."
Jun 29th 2020
EXTRACT: "Numerous studies have shown that children who grow up in more deprived neighbourhoods tend to have worse physical health as adults compared to those raised in more affluent areas. This is the case even when researchers take into account family income and education, and whether or not parents have major illnesses. In order to address this health disparity, researchers need to understand how those living in disadvantaged neighbourhoods end up with worse health outcomes. Our team’s latest study has highlighted one potential way your childhood neighbourhood may influence your health for years to come. It might do so through changing how the activity of your genes is regulated."
Jun 29th 2020
EXTRACT: "Ruth Poniarski is a painter and the author of Journey of the Self: Memoir of an Artist (Warren Publishing, 2020), in which she tells the story of her decade long struggle with mental illness, a “spiraling malady” which led her into a “pattern of psychosis”. I recently had the opportunity to talk with Poniarski about her life and work, and how she eventually overcame her demons."
Jun 27th 2020
EXTRACT: "I know I’m good in a couple of things, really good in a few things, and that’s enough. My confidence is big enough that I can really let people grow next to me, it’s no problem. I need experts around me. It’s really very important that you are empathetic, that you try to understand the people around you, and that you give real support to the people around you."
Jun 27th 2020
An essay about the "the enormously influential 1940 'Head of Christ' painting by evangelical Warner E. Sallman" pictured below.
Jun 17th 2020
EXTRACT: "The diverse, non-human life forms that live in our guts – known as our microbiome – are crucial to our health. A disrupted balance of these contribute to a range of disorders and diseases, including obesity, diabetes, inflammatory bowel disease. It could even affect our mental health..... It’s well known that the microbes living in our guts are altered through diet. For example, including dietary fibre and dairy products in our diets encourages the growth of beneficial bacteria. But mounting evidence suggests that exercise can also modify the types of bacteria that reside within our guts."
Jun 13th 2020
EXTRACT: "Bonhoeffer’s life holds an important lesson for us today, regardless of our religious affiliation or lack thereof. And simply put it is this: you are called upon; you are called on behalf of your neighbor. When you are called to be responsible that is not an obligation which you can decline, discharge or acquit yourself of – it is an infinite responsibility, a “forever commitment” as Charles Blow recently put it. And we all must be prepared to make any sacrifice necessary when we are called."
Jun 11th 2020
EXTRACT: "People differ substantially in how much they’re affected by experiences in their lives. Some people seem to be more affected by daily stress, or the loss of someone close to them. On the other hand, some people seem to get through the same experiences relatively unscathed. Similarly, some people benefit strongly from counselling, or having a support system of close family and friends. Others seem better able to manage on their own. But understanding why some people are more sensitive than others isn’t just a question of how they were raised, and the experiences they’ve been through. In fact, previous research has found that some people in general seem more sensitive to what they experience – and some are generally less sensitive."
Jun 7th 2020
EXTRACT: " The root causes of anthropogenic climate change – which has led to the endangering of countless species across the globe – cannot be adequately grasped in isolation from the technological application of modern science. While Swedish activist Greta Thunberg was certainly justified in calling upon American legislators to “unite behind the science,” neither can we overlook the culpability of science in bringing about the environmental crisis. "
May 23rd 2020
EXTRACT: "The QAnon movement began in 2017 after someone known only as Q posted a series of conspiracy theories about Trump on the internet forum 4chan. QAnon followers believe global elites are seeking to bring down Trump, whom they see as the world’s only hope to defeat the “deep state.” OKM is part of a network of independent congregations (or ekklesia) called Home Congregations Worldwide (HCW). The organization’s spiritual adviser is Mark Taylor, a self-proclaimed “Trump Prophet” and QAnon influencer with a large social media following on Twitter and YouTube."
May 23rd 2020
EXTRACT: "The aim of my research for the Understanding Unbelief programme was to investigate the worldviews of non-believers, since little is known about the diversity of these non-religious beliefs, and what psychological functions they serve. I wanted to explore the idea that while non-believers may not hold religious beliefs, they still hold distinct ontological, epistemological and ethical beliefs about reality, and the idea that these secular beliefs and worldviews provide the non-religious with equivalent sources of meaning, or similar coping mechanisms, as the supernatural beliefs of religious individuals."
May 22nd 2020
EXTRACT: "Psalm 91, for example, reassures believers that God will protect them from “the pestilence that walketh in darkness… A thousand shall fall at thy side, and ten thousand at thy right hand; but it shall not come nigh thee”.............Luther was a devout believer but insisted that religious faith had to be joined with practical, physical defences against sickness. It was a good Christian’s duty to work to keep themselves and others safe, rather than relying solely on the protection of God. "
May 22nd 2020
EXTRACT: "Evidence from this study shows clearly that eating foods rich in flavonoids over your lifetime is significantly linked to reducing Alzheimer’s disease risk. However, their consumption will be even more beneficial alongside other lifestyle changes, such as quitting smoking, managing a healthy weight and exercising."
May 5th 2020
EXTRACT: "It’s possible that the answers to questions like, “how do I live a virtuous life?” or “how do we build a good society?” are not the same as they were a few weeks ago."
May 2nd 2020
EXTRACT: "Strangely, those with strong beliefs tend to be admired. The human mind hates uncertainty, so it is comforting to be told what to think, and to form settled opinions. But it is not rational. As the philosopher Bertrand Russell wrote: “The fundamental cause of the trouble is that in the modern world the stupid are cocksure while the intelligent are full of doubt.”
Apr 21st 2020
Extract: "Humans, Boccaccio seems to be saying, can think of themselves as upstanding and moral – but unawares, they may show indifference to others. We see this in the 10 storytellers themselves: They make a pact to live virtuously in their well-appointed retreats. Yet while they pamper themselves, they indulge in some stories that illustrate brutality, betrayal and exploitation. Boccaccio wanted to challenge his readers, and make them think about their responsibilities to others. “The Decameron” raises the questions: How do the rich relate to the poor during times of widespread suffering? What is the value of a life? In our own pandemic, with millions unemployed due to a virus that has killed thousands, these issues are strikingly relevant.
Apr 20th 2020
Extract: "If we do not seize this crisis as a moment for transformation, then we will have lost the war. If doing so requires reviving notions of collective guilt and responsibility – including the admittedly uncomfortable view that every one of us is infinitely responsible, then so be it; as long we do not morally cop out by blaming some group as the true bearers of sin, guilt, and God’s heavy judgment. A pandemic clarifies the nature of action: that with our every act we answer to each other. In that light, we have a duty to seize this public crisis as an opportunity to reframe our mutual responsibility to one another and the world."
Apr 16th 2020
EXTRACT: "Death is the common experience which can make all members of the human race feel their common bonds and their common humanity."
Apr 7th 2020
EXTRACT: "A crisis such as this one demands that we exercise what the philosopher Immanuel Kant called the ‘public use of reason’ – as opposed to merely the ‘private use of reason’ where, briefly put, the expert, the specialist is tasked with resolving a defined problem. The private use of reason is sufficient when we are dealing with a problem that can be solved by simply applying the appropriate expertise...............The public use of reason asks: how we are defining the problem? Is our definition – our conceptualization of the problem – perhaps part of the problem itself? Is this pandemic solely a problem of public health, or is it also a problem of extreme economic inequality? ..............Since this crisis began, the greatest failure of the administration is not the denial, the lies, the lack of preparedness, but the inability to rally and unify the nation against this common threat, the lack of genuine leadership – Trump’s utter inability to bring the nation together."
Apr 5th 2020
EXTRACT: "Rarely has an architectural experiment aroused such extremes of ire and admiration. One side is convinced the house is a masterpiece. The other expresses brutal condemnation of the entire project (leaky roof, danger of flooding, too-hot, too-cold interiors depending on the American Midwest weather).........Farnsworth encapsulated her personal ambiguity in her comment to a Newsweek interviewer: “This handsome pavilion I own is almost totally unworkable.” She told one journalist, “ … all I got was this glib, false sophistication. The conception of a house as a glass cage suspended in air is ridiculous.”