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

Apr 1st 2020
Ambrogio Lorenzetti, Effects of Good Government fresco, Palazzo Pubblico, Siena.
Mar 29th 2020
EXTRACT: "The coronavirus crisis has forced us to look at our behaviour in a way that we’re not used to. We are being asked to act in the collective good rather than our individual preservation and interest. Even for those of us with the best of intentions, this is not so easy."
Mar 23rd 2020
EXTRACT: "In March 2020, my sister Nancy and I did something that, as scholars, we had never done before: we wrote about ourselves, comparing our own experiences receiving cancer care on either side of the Atlantic. As we recently reported in the BMJ, much of our experience is similar. As twins, we both have the same form of cancer. Both of us received excellent treatment in well-established university teaching hospitals. Both of us are now in remission. But there is a glaring difference. Nancy lives in the US, covered under a good private healthcare scheme. I live in the UK, covered by the NHS."
Mar 21st 2020
EXTRACT: "In philosophy, individualism is closely linked with the concept of freedom. As soon as restrictive measures were imposed in Italy, many people felt that their freedom was threatened and started to assert their individuality in various ways. Some disagreed with the necessity of cancelling group gatherings and organised unofficial ones themselves. Others continued to go out and live as they always did. We often assume that freedom is to do as we choose, and that is contrasted with being told what to do. As long as I am doing what the government tells me, I am not free. I am going out, not because I want to, but because that shows I am free. But there is another route to freedom..........."
Mar 12th 2020
EXTRACT: "Repeated stress is a major trigger for persistent inflammation in the body. Chronic inflammation can lead to a range of health problems, including diabetes and heart disease. The brain is normally protected from circulating molecules by a blood-brain barrier. But under repeated stress, this barrier becomes leaky and circulating inflammatory proteins can get into the brain. The brain’s hippocampus is a critical brain region for learning and memory, and is particularly vulnerable to such insults. Studies in humans have shown that inflammation can adversely affect brain systems linked to motivation and mental agility. There is also evidence of chronic stress effects on hormones in the brain, including cortisol and corticotropin releasing factor (CRF). High, prolonged levels of cortisol have been associated with mood disorders as well as shrinkage of the hippocampus. It can also cause many physical problems, including irregular menstrual cycles."
Mar 12th 2020
EXTRACT: "It’s important to do things that make you happy or content as you are doing them – and doing them for yourself. Research has found that picking recovery activities you find personally satisfying and meaningful is more likely to help you feel recovered by the next morning."
Feb 22nd 2020
EXTRACTS: "A recent study of nearly 3,000 physicists found that a scientist’s most highly cited publication had an equal probability of being published at any point within the sequence of papers the scientist published.........Creativity is not the prerogative of the young, but can occur at any stage in the life cycle...........there is not a single kind of creativity, but that in virtually every intellectual discipline there are two different types of creativity, each associated with a distinct pattern of discovery over the life cycle. The bold leaps of fearless and iconoclastic young conceptual innovators are one important form of creativity. Archetypal conceptual innovators include Einstein, Picasso.......very different type of creativity, in which important new discoveries emerge gradually and incrementally from the extended explorations of older experimental innovators.......The single year from with Paul Cézanne’s work is most frequently illustrated in textbooks of art history is 1906 – the last year of his life, when he was 67."
Feb 22nd 2020
EXTRACT: "As our global population is projected to live longer than ever before, it’s important that we find ways of helping people live healthier for longer. Exercise and diet are often cited as the best ways of maintaining good health well into our twilight years. But recently, research has also started to look at the role our gut – specifically our microbiome – plays in how we age."
Feb 16th 2020
EXTRACT: "In an increasingly polarised political landscape, we see differing political views challenged, not through debate and discussion, but through tribal behaviour. We often consider the groups that we belong to as worthy of empathy, respect and tolerance – but not others. What’s more, recent research has identified that we reward our leaders for being naysayers – negating, refuting or criticising others – rather than empowering them."
Feb 14th 2020
EXTRACT: "All of which is to say that the Communist Manifesto is not a historical relic of a bygone era, an era of which many would like to think we have washed our hands. As long as workers’ rights are trampled on, and children are pressed into wretched servitude; as long as real wages stagnate, so that economic inequality continues to grow, allowing wealth to be ever more concentrated in the hands of the few – then the Communist Manifesto will continue to resonate and we will hear the clarion call of workers of the world to unite, “for they have nothing to lose but their chains. They have a world to win.” "
Feb 4th 2020
EXTRACTS: "In my many visits to Michael’s studio I have had the opportunity to observe his process up close and over time.............."Armageddon Yacht (2019)". The name is derived from a term that US sailors use for an aircraft carrier. Power and violence are recurring themes in Anderson’s work – and no less here. With irony and wit he questions our contemporary assumptions and illusions about power. The central image of three models sipping martinis on a yacht presents us with an idealized vision of Western luxury and decadence, privilege and wealth."
Jan 23rd 2020
EXTRACT: " For the first time in over two decades a painting by Marc Chagall will be going up for auction in Israel. Tiroche Auction House will be hosting the Israeli & International Art auction on January 25th – featuring paintings by a number of Israeli masters, including Reuben Rubin, and Yosl Bergner. The highlight of the evening however is Chagall’s Jacob’s Ladder (1970-1974), a theme to which the artist would return at least a dozen times in paintings and drawings."
Jan 16th 2020
EXTRACT: "Between 1940 and 1942 Charlotte Salomon, a young German-Jewish artist, created a sequence of 784 paintings while hiding from the Nazi authorities. She gave the sequence a single title: Leben? oder Theater? (Life? or Theatre?). Viewed in the 21st century, Salomon’s artwork could be considered a precursor to the contemporary graphic novel, creating a complex web of narratives through words and images."
Jan 9th 2020
EXTRACT: "It’s simply not possible to do justice to the value of Iran’s cultural heritage – it’s a rich and noble history that has had a fundamental impact on the world through art, architecture, poetry, in science and technology, medicine, philosophy and engineering. The Iranian people are intensely aware – and rightly proud of – their Persian heritage. The archaeological legacy left by the civilisations of ancient and medieval Iran extend from the Mediterranean Sea to India and ranges across four millennia from the Bronze age (3rd millennium BC) to the glorious age of classical Islam and the magnificent medieval cities of Isfahan and Shiraz that thrived in the 9th-12th centuries AD, and beyond."
Jan 9th 2020
EXTRACT: "Lautrec had a genius for representing people. He would rarely paint any other subject. When he looked at a person who caught his interest, not only their appearance, but seemingly also their personality would magically flow from his hand, fixing a moment of their life, and his, on a piece of cardboard or canvas."
Jan 7th 2020
EXTRACT: "In 2010, Great Britain generated 75% of its electricity from coal and natural gas. But by the end of the decade*, these fossil fuels accounted for just 40%, with coal generation collapsing from the decade’s peak of 41% in 2012 to under 2% in 2019. The near disappearance of coal power – the second most prevalent source in 2010 – underpinned a remarkable transformation of Britain’s electricity generation over the last decade, meaning Britain now has the cleanest electrical supply it has ever had. Second place now belongs to wind power, which supplied almost 21% of the country’s electrical demand in 2019, up from 3% in 2010. As at the start of the decade, natural gas provided the largest share of Britain’s electricity in 2019 at 38%, compared with 47% in 2010."
Jan 5th 2020
EXTRACT: "Owing to these positive developments, many were lulled into thinking that modern advanced economies can run on autopilot. And yet economists knew that market capitalism does not automatically self-correct for adverse distributional trends (both secular and transitional), especially extreme ones. Public policies and government services and investments have a critical role to play. But in many places, these have been either non-existent or insufficient. The result has been a durable pattern of unequal opportunity that is contributing to the polarization of many societies. This deepening divide has a negative spillover effect on politics, governance, and policymaking, and now appears to be hampering our ability to address major issues, including the sustainability challenge."
Jan 2nd 2020
In September 2018, Ian Buruma was forced out as editor of The New York Review of Books, following an outcry over the magazine’s publication of a controversial essay about #MeToo. A year later, in a conversation with Svenska Dagbladet US correspondent Malin Ekman, he reflects on lost assignments, literature, cancel culture, threats to freedom of speech, and the state of liberal democracy.
Dec 31st 2019
EXTRACT: "I have long been troubled by the way so many believing Christians in the West have either been ignorant of or turned their backs on the plight of Palestinians, both Christian and Muslim. Right​-wing Evangelicals, under the sway of heretical theology, are so blinded by their obsession with Israel that they can't see Israel's victims. Other Western Christians simply just don't know or about the people of Palestine. I find this state of affairs to always distressing, but especially so at Christmas time, since the Christmas story we celebrate not only took place in that land, it continues to define the lives of the Palestinians who live in places like Bethlehem and Nazareth. "
Dec 19th 2019
EXTRACT: "Although there have long been farmers and merchants who specialised in growing and selling seeds, it wasn’t until the 20th century that people started talking about seed production as an industrial process. Thanks to changes in farming, science and government regulations, most of the “elite” seed that is bought and sold around the world today is mass produced and mass marketed — by just four transnational corporations."