As an artist, when I hear the word FIBER, I first think of weaving, rugs, quilting, or clothing, which are often thought of as the homemaking arts. While these are often done by women, men also find some claim to fame also. The late artist Christo and Jean-Claude’s “The Gates,” in New York’s Central Park, is an example his visionary use of fabric to wrap buildings and to define natural spaces.
Likewise when we talk about diets, some keep close to the utilitarian needs of the body and food, while others stretch an idea to its most fanciful extreme. This leads us to ask: “What’s a Real Live Paleo People’s Diet?”
The food plan we know today as Paleo focuses on “foods our hunter-gather ancestors would have eaten, with an emphasis on meat.” It eschews grains, sugars, and modern vegetable oils in favor of high-quality meat, fish, eggs, and vegetables. Some folks want you to believe it’s an “All The Bacon You Can Eat Diet,” but they missed the message on high quality. Perhaps they they heard “high quantity “ instead.
We modern people don’t have access to the same foods as those who live in nature all the time and get all their food by foraging or hunting. Our modern chickens are raised in concentrated animal feeding operations, in crowded buildings, and fed a scientific diet meant to fatten them up in the shortest possible time. This is why modern chickens are almost all white meat, since the birds rarely use their muscles any more. Our grains are designed for maximum yield and insect resistance. Many of our crops are also resistant to weed killers. Of course, we can buy organic products, but their costs are higher due to the greater labor used to bring in a crop equal to those using chemicals.
We also live in communities, rather than in small groups, so we have access to supermarkets, restaurants, and fast food joints. The more processed our food, the fewer and less diverse our gut biome will be. For instance, if all we eat is biscuits and gravy or burgers and fries at our local window of death, our lives are going to be shorter and less healthy. We know this by studying stool samples. Yep, there are scientists who look at poop. They’ve discovered evidence that our intestinal microbes are profoundly influenced by the foods we eat — or don’t: The gut ecosystems of members of a small group of hunter-gatherers inhabiting Tanzania’s Rift Valley show a strong cyclicality consistent with the population’s seasonally changing diet. The average diet of a western person produces a much less diverse gut biome, primarily due to our low intake of fiber.
seasonal variation in gut-microbe diversity
Researchers at the Stanford University School of Medicine were the first to look at seasonal variations in the gut-microbial composition, or microbiota, of the Hadza, one of the world’s few remaining traditional hunter-gatherer populations. The research confirms that the Hadza microbiota is more diverse than, and substantially different from, that of industrialized countries’ urban-dwelling denizens.
The study was also the first to show that the microbiota of the Hadza population varied seasonally, and that this variation corresponded to their seasonally fluctuating dietary intake.
For more than 15 million years, human beings have co-evolved with thousands of microbial species that take up residence in the lowermost part of the intestine. They earn their keep by helping us:
1. digest food components we’re unable to break down by ourselves, chiefly dietary fiber;
2. manufacturing vitamins and other health-enhancing molecules;
3. training our immune system and fostering the maturation of cells in our gut; and
4. guarding our intestinal turf against the intrusion of all-too-eager competing microbial species, including pathogens.
The advent of agriculture about 10,000 to 15,000 years ago has radically altered our diet. In the past century alone, the typical person’s lifestyle has undergone further vast alterations: labor-saving devices’ encourages a sedentary existence, the introduction of antibiotics and cesarean section births, and the gradual supplanting of fiber-filled whole grains, fruits and vegetables by increasingly processed and fiber-free foods.
These environmental changes have brought corresponding shifts in our microbial exposures, and in our intestines’ ability to serve as hospitable hosts for these symbionts, which are organisms living cooperatively within one another. But it’s been hard to apportion the relative contributions of technological and societal innovations to the loss of microbial diversity in modern populations. The Hadza study adds evidence that our diet is a major factor in our gut biome population and constitution.
The Hadza number just over 1,000 people, but only fewer than 200 of whom adhere to the traditional hunter-gatherer lifestyle, which includes a diet composed mainly of five items: meat, berries, baobab (a fruit), tubers and honey. While Western diets are pretty much the same throughout the year, the Hadza lifestyle doesn’t include refrigerators and supermarkets. So the population’s diet fluctuates according to the season, of which there are two in the Rift Valley: dry—when meat, baobab and tuber consumption play a relatively larger role; and wet—during which berries, tubers, honey and baobabs prevail. (Tubers and baobab are available year-around.)
“The 100 to 200 Hadza sticking to this routine will possibly lose it in a decade or two, maybe sooner. Some are using cell phones now,” says Justin Sonnenburg, a microbiologist at Stanford University. “We wanted to take advantage of this rapidly closing window to explore our vanishing microbiota.”
The investigators collected 350 stool samples from 188 separate Hadza individuals over a roughly one-year period encompassing a bit more than one full seasonal cycle. A thorough analysis of the samples’ microbial contents revealed that the gut microbiota varied seasonally, in harmony with the Hadza dietary intake. In particular, a subset of microbial species’ populations diminished in the wet season, when honey accounted for a significant portion of caloric intake, and rebounded in the dry season, when consumption of fiber-rich tubers peaked.
The further away people’s diets are from a Western diet, the greater the variety of microbes they tend to have in their guts. And that includes bacteria that are missing from American guts.
“So whether it’s people in Africa, Papua New Guinea or South America, communities that live a traditional lifestyle have common gut microbes — ones that we all lack in the industrialized world,” Sonnenburg said.
In a way, the Western diet — low in fiber and high in refined sugars — is basically wiping out species of bacteria from our intestines. That’s the conclusion Sonnenburg and his team reached after analyzing the Hadza microbiome at one stage of the yearlong study.
But when they checked several months later, they uncovered a surprising twist: The composition of the microbiome fluctuated over time, depending on the season and what people were eating. And at one point, the composition started to look surprisingly similar to that of Westerners’ microbiome.
During the dry season, Hadza eat a lot more meat, as most Westerners do. When their diet changed, their microbiome shifted as well. Some of the bacterial species that had been prevalent disappeared to undetectable levels, similar to what’s been observed in Westerners’ guts.
But then in wet season — when Hadza eat more berries and honey — these missing microbes returned, although the researchers aren’t really sure what’s in these foods that bring the microbes back.
“We’re beginning to realize that people who eat more dietary fiber are actually feeding their gut microbiome,” Sonnenburg says.
Hadza consume a huge amount of fiber because throughout the year, they eat fiber-rich tubers and fruit from baobab trees. These staples give them about 100 to 150 grams of fiber each day. That’s equivalent to the fiber in 50 bowls of Cheerios — and 10 times more than many Americans eat. “Over the past few years, we’ve come to realize how important this gut community is for our health, and yet we’re eating a low-fiber diet that totally neglects them,” he says. “So we’re essentially starving our microbial selves.”
“I think this finding is really exciting,” says Lawrence David, who studies the microbiome at Duke University. “It suggests the shifts in the microbiome seen in industrialized nations might not be permanent — that they might be reversible by changes in people’s diets.
In closing, while we can’t all move to Tanzania and give up our day jobs, we all could incorporate more whole grains and less processed food. If we make a plan to try one new food each week, we can train our palettes to accept novel tastes and textures. We don’t need to buy 10 pounds of a new food! One pound would do, and we can learn a new recipe. This way we stretch our minds and learn a new trick. I remember learning to appreciate liver on one of these “try something new days.” I held out till I was hungry and then my dinner tasted ever so good! Search the outer aisles and look for foods in their simple state, rather than boxed in a mix.
The average adult person in the USA only gets about 15 grams of fiber daily, despite national health goals to increase intake. The message isn’t getting out. You can use the nutrition information on your package to check for the amount of fiber. For fruits and vegetables, a quick Google search will bring up the answer. I look for at least 3 grams of fiber in any item I purchase. This rules out “white” rice, bread, and most pasta products, but brown rice, whole wheat, and whole whole grain pasta and some bean product pastas can freely substitute for the other. The good news is these fill you up more because of the fiber, so hunger between meals isn’t as much of a problem. They also keep your blood sugar from spiking and crashing, which is another problem many with prediabetes and diabetes have.
Aim for 25 to 30 grams of fiber daily from your food sources. My morning old fashioned oatmeal contains 4 grams of fiber, the nuts add 2 grams, and the tablespoon of cocoa an additional 2 grams for a total of 8 grams of fiber. I’m already a third of the way there, and I’ve even had a chocolate fix! I usually add a 1/3 cup of instant nonfat milk and a pat of butter to my oatmeal with some vanilla and Splenda. If I can’t enjoy life, especially food, I won’t keep to my food plan.
My “hunting and gathering” is mostly done at my local grocery store, but I have four servings of lentil soup I made yesterday in the old crockpot from the rotisserie chicken and a frozen soup veggie package, to which I added garlic and Italian spices, plus an onion. Today it’s pouring down rain and I feel like doing nothing at all, except maybe a little laundry. Or maybe more coffee! I can always get excited for coffee!
Joy and Peace,
Cornie
Hadza Hunter Gathers Seasonal Gut Microbe Diversity Study
King DE, Mainous AG 3rd, Lambourne CA. Trends in dietary fiber intake in the United States, 1999-2008. J Acad Nutr Diet. 2012 May;112(5):642-8. doi: 10.1016/j.jand.2012.01.019. Epub 2012 Apr 25. PMID: 22709768.
https://pubmed.ncbi.nlm.nih.gov/22709768/
Healthy Beans and Legumes
https://www.healthline.com/nutrition/healthiest-beans-legumes
The Standard American Diet
https://www.psychologytoday.com/us/blog/food-junkie/201308/the-american-diet
Cornie's Kitchen 