Recently, knowledge about the importance of human interaction with microorganisms is questioning the lifestyle of many societies while recognizing the importance of biodiversity in every way.
We had the pleasure of talking to Dr. Clelia Peano, a researcher of the Institute of Genetic and Biomedical Research CNR and Head of Genomic Unit at Humanitas Clinical Center in Milan, Italy. Clelia is part of a group of researchers studying the intestinal microbiome with an aim to understand the functions of microorganisms and their impacts on human health.
It is worth mentioning that the importance of the microbiome is recently recognized by the scientific community. Only since the year 2000, the interactions of microorganisms with their host (animals (humans), plants, soil, water) are known to be relevant to the sustainability, balance and overall health of all constituents within the ecosystem.
But now, let’s allow Clelia to explain it to us:
What is the microbiome?
The microbiome is composed of all microorganisms (e.g. bacteria, fungi, etc.) that colonize an environment. It constitutes an ecosystem.
What is the human microbiome and why is it important?
The human microbiome refers to all microorganisms (e.g. bacteria, fungi) that live within our body.
Inside the human body, the skin and the intestine are the organs that are colonized by the largest diversity of bacterial species (more than one thousand species), followed by the oral and pharyngeal tract (more than six hundred spices).
The microbiome is important because our body is dominated by bacteria. As a matter of fact, the bacterial cells colonizing our body are 10 times more abundant than are our human cells.
Inside the intestine, microorganisms exert very important functions such as extracting energy from food, producing vitamins and regulating the immune system, glucose level and metabolism.
How does the microbiome control these body functions?
The microbiome produces metabolites that can contribute to maintain a systemic state of equilibrium or, in some cases, can cause diseases.
The alteration of the correct balance between the microbiome and the immune system is known as dysbiosis, and it can be correlated with the occurrence of diseases such as asthma, diabetes, obesity, liver disease, depression, heart disease, colon cancer and inflammatory bowel disease.
What is the difference between a healthy microbiota and a sick microbiome?
An important difference is related to the relative abundance between different kinds of bacteria. For example, a sick or dysbiotic microbiome has a higher ratio between femicutes/bacteroidetes, and can lead to a systemic inflammation, while a healthy microbiome exhibits a higher bacteroidetes/fermicutes ratio that may be correlated with the maintenance of low levels of inflammation.
What factors influence the microbiome composition?
First of all, the microbiome is an ecosystem that responds and continuously adapts to the organism that hosts it; in this case to our body and lifestyle.
The factors that influence the microbiome composition are:
food: a diet poor in fiber, high amounts of processed foods and high levels of sugars, predisposes to gut microbiome dysbiosis;
lifestyle: poor physical activity and excessive/use of drugs can compromise the balance of our microbiome. For example, excessive use of opioids can slow down the digestive process, antipsychotics can have a direct antibacterial effect, gastroprotectors can cause gastric cancer;
genetic predisposition: our genes play an important role in shaping our intestinal microbiome, this was demonstrated in a study in which from the analysis of 416 pairs of twins, it was observed that identical twins (homozygotes) have a microbiome more similar to each other than different twins (heterozygous).
Two stories to better understand how the intestinal microbiome evolves and transforms, adapting itself over the course of human lives:
1. Comparison between the intestinal microbiome of Hazda and Italians:
We compared the microbiome of two very different populations: the Hazda, and the Italians.
The Hadza are a nomadic population living in Africa (Tanzania). They are the last Human hunters and gatherers living on Earth. They have a lifestyle similar to that of the people who lived in the Paleolithic era which occurred more than 10,000 years ago. They have never experienced either agriculture or farming.
Italians, on the other hand, are a settle/civilized population living in Europe. They have a western lifestyle and live in urbanized environments.
The Hadza microbiome is dominated by bacteria that serve to degrade fibers while the microbiome of Italians is specialized in the degradation of carbohydrates. Since the diets of these two peoples have a very different composition, the diet of the Hadza is much more diversified and involves the consumption of large quantities of fiber and protein, while the diet of Italians is made up of more than 50% of carbohydrates.
In the Hadza microbiome, there are no Bifidobacteria, which are present in the microbiome of all other human beings. Their microbiome is different from that of all other peoples: Africans, Europeans and Americans.
The Italian Microbiome is rich in bacteria that perform functions to metabolize drugs, antibiotics and pollutants. These functions are totally absent in the Hadza microbiome.
Genes for antibiotic resistance in the Hadza intestine are derived from soil bacteria, which are antibiotic producers, and give an advantage to them.
Genes for antibiotic resistance in the intestines of Italians derive from the excessive use of these drugs and are a disadvantage for us.
2.Comparison between the intestinal microbiome of newborns and centenarians:
To understand how the microbiome develops and transforms itself over the course of our life, we compared the microbiome of individuals of very different ages: newborns and centenarians.
The microbiome of infants is dominated by Bifidobacteria, which are essential for the digestion of oligosaccharides (sugars polymers) contained in breast milk and for the correct development of the immune system.
The interruption of breastfeeding allows the complete maturation of the intestinal microbiome of the newborn.
The species and bacterial strains found in the microbiome of newborns derive from the mother’s microbiome. The mother is the main source.
The microbiome is essential for the correct development of the immune system in newborns.
The intestinal microbiome of centenarians and ultra-centenarians is different from the microbiome that colonizes human bodies during the rest of life.
In Centenarians and ultra-centenarians, the microbiome is essential for maintaining the state of health and balance within the immune system. Their microbiome is characterized by the presence of the bacterial genus Christensenellaceae.
What are the advantages of the clinical study of the intestinal microbiome?
The study of the intestinal microbiome can be fundamental for prevention, early diagnosis and therapy and can help to successfully integrate drug therapies while utilizing a personalized diet.
What awaits us in the future?
Once reliable markers associated with the intestinal microbiome dysbiosis in relation to the onset of pathologies is established and validated, it will be possible to integrate microbiome analysis (from fecal samples) with other non-invasive analysis (urine, blood and saliva samples) to combine different clinical parameters and thus obtain a complete diagnosis that can allow us to identify personalized therapies that include the correct and personalized prescription of drugs and diet.
In addition, information about genes and metabolites can help doctors to provide a more effective, comprehensive and personalized health care plan for each individual in the future.
Our lifestyle (nutrition, exercise, drug intake) affects our health. The quality of the food we eat, the quantity and the diversity in our diet influences the balance of our microbiome and, consequently, our health.
Biodiversity and integration: Biodiversity is always positive both in the environment and within our gut. Let’s respect and improve biodiversity by all means!
Another important point to consider is that the excessive use of antibiotics (in humans, animals and plants) not only affects the microbiome but also causes resistance. Antibiotic resistance is a major problem today! To get an idea, watch this video that illustrates the problem and, for more information, check out the World Health Organization webpage dedicated to this topic. We will develop more on this topic in future posts. Stay tuned!
As Hippocrates, the father of medicine, already stated ca. 460 BC, …”Let food be thy medicine and thy medicine your food”… ourhealth is directly related to the food we consume!
This raises up the question, what shall we eat to be healthy?
The WHO (World Health Organization of the United Nations) emphasizes the importance of eating fruits, vegetables and legumes, and to restrict consumption of free sugars, trans-fats and salt.1
Importantly, it points out that diets evolve over time, being influenced by social and economic aspects including cultural traditions, individual beliefs and preferences, food prices and environmental factors.1 Therefore, an ideal diet can only be established inside the local contexts, meaning that there is a huge diversity of diets.
In recent years, the awareness
regarding a sustainable way of eating has increased.
For FAO (Food and Agriculture Organization of the United Nations)…”sustainable diets are diets with low environmental impact which contribute to food and nutrition security and to healthy life for present and future generations. Sustainable diets are protective and respectful of biodiversity and ecosystems, culturally acceptable, accessible, economically fair and affordable; nutritionally adequate, safe and healthy; while optimizing natural and human resources.”…2
So, sustainable diets are
healthy diets for which the economic, social and environmental aspects are
taken in consideration, right?
A nice way of looking at the relationship between the nutritional value of food and its environmental impact is the double food and environmental pyramid model developed by the Barilla Center of Food and Nutrition and adapted to the Italian Mediterranean diet. For example, animal products that have a high environmental impact (bottom of the environmental pyramid) are recommended to be consumed in low amounts (top of the food pyramid) and fruits and vegetables that have a low environmental impact (top of the environmental pyramid) are recommended to be consume in high amounts (bottom of the food pyramid).
Of course, all of this has to considered
within the local context. If you live in north Canada as Inuit do, you might
not be able to eat lots of fresh fruits and vegetables and you probably get
high quantities of animal products, and that is ok! In fact, for centuries, we
all have adapted to our local conditions by eating mostly local food.
And very importantly, we shall
not all eat the same to be healthy. For example, indigenous people inside the
amazon don’t need wheat as a source of carbohydrates as they have manioc, they don’t
need olive oil as they have other sources of healthy fats (e.g. sacha ichi, Brazilian
nut, macambo), they don’t need salmon as they have paiche. Wouldn’t you agree?
And we are not saying we should eat strictly local food but, if we prefer it on regular basis, we support the local economy, preserve local traditions and protect local environments.
A very interesting article presented in the National Geographic magazine shows the evolution of diets and how similar or diverse these are in different countries. Really worth seeing.
According to FAO, diets that are
healthy and sustainable have the following characteristics:2
diverse (a wide variety of food)
balance between energy intake and
energy needs (or eat what the body needs)
based on minimally processesed tubers
and whole grains; legumes; fruits and vegetables – particularly those “robust”
(or less prone to spoilage) and those which require less of rapid and more
energy-intensive transport. Meat, if eaten, in moderate quantities – and all
animal parts consumed
eat in moderation: dairy products
or alternatives (e.g. fortified milk substitutes and other food rich in calcium
unsalted seeds and nuts
small quantities of fishand aquatic products sourced from
very limited consumption of food high in fat, sugar or salt and low in micronutrients (e.g. crisps,
confectionery, sugary drinks)
oils and fats with a beneficial
omega 3-6 ratio such as rapeseed, olive oil, avocado oil (and others)
tap water in preference to
In fact, these characteristics can be adapted to all
diets, don’t you think?
But let’s wait a second, before industrialization and globalization,
weren’t these characteristics followed by most cultures? It might be wise to look back and retake some food habits practiced by
A practical example of a healthy and sustainable dish
has recently been presented in the study of the EAT-Lancet Commission.3 Worth seeing!
Why is diversity so important?
The diversity of diets is not only key for protecting the
loss of biodiversity (i.e. genetic, species and ecosystem diversity4) and environment degradation but to preserve human food cultural knowledge
Keep in mind that diversified varieties, cultivars, and breeds of the same food have different nutritional content.4
Since the beginning of agriculture (ca. 12000 years
ago), we have faced a dramatic loss of plant and animal species used by humans as
food. For example in Thailand, from the 16,000 varieties of rice traditionally
cultured, today, only 37 are being cultivated.4
Not all of us should be eating the same things. Local traditions need to be
preserved for our health and for the health of our planet!
Recently, a scientific study has quantified the mass
of life on earth (biomass) and has shown that within the animal kingdom (2% of
the entire biomass), there are many more humans than wild animals and that
there is around 40% more livestock than humans.5 This is crazy!
Accrording to FAO, countries, communities and cultures maintaining their traditional food systems not only conserve their local food specialties with the corresponding diversity of crops and animal breeds but are also less likely to suffer diet-related-diseases.4
A great scientific work safeguarding agricultural and
tree diversity to achieve a sustainable global food and nutrition security is
being performed by Biodiversity
International. One recent publication has shown that a great
diversity of cultivated vegetable species (1097) still exist around the world –
some of which could have the potential for a widespread diffusion, and many others
could fulfil important roles in nutrition at the local context.6
Also, a nice photographic social study performed by Peter Menzel and Faith D’Aluisio is presented in several books that
can be viewed online. They show photos and information about food habits and traditions of
people around the world. Really worth looking!
Why are we losing traditional food heritage?
industrial development, population increase and urbanization have changed
patterns of food production and consumption affecting deeply ecosystems and
For different reasons, the global market requires high
yields of some foods to be commercialized around the globe at a low price. This
need has pushed agriculture towards intensive farming and the cultivation of big
areas of monocultures and livestock. The abundance of these “cheap” global foods
(cheaper than locally produced foods) has simplified diets and damaged the
ecosystem (intensive-use fertilizers, pesticides, antibiotics, deforestation,
etc.). We will talk more about this topic, so stay tuned!
Also, to understand
our current food system better, have a look at the YouTube video created by Denis van Waerebeke (available in English with subtitles in many languages) which explains
the global players, dynamics, problems and inequalities affecting food
production and what can we do to be part of the solution. Worth watching!
The simplification of diets, the decline in
consumption of local nutritional food and the little time/interest we invest in
our food (cultivation, selection, preparation) are related to the increase incidence
of chronic diseases (nutritionally-poor and energy-rich).
Poor dietary habits and unhealthy diets are the cause of many nutrition
Interestingly, before all the scientific and
nutritional awareness about food (mostly on individual nutrients), culture
mediated the relationship between people and nature, and therefore, people’s
relationship with food as well. Industry, wanting to sell more, has undermined
the authority of traditional ways of nourishment, impacting how we eat and
causing serious harm to human health.
Food as a Public Health Problem
Today, 815 million people are undernourished7 while 1.9 billion are overweight, and from this 650
million obese.8 About half the global population is inadequately nourished (hunger,
micronutrient deficiencies and overweight/obesity).9
If we think
about it, these pandemic nutrition problems are a direct consequence of food waste
(link to post 3). Not only does our current food system waste 1.3 billion
tonnes per year10, but we waste food when we eat more that we need.
To waste food means not consuming it and overconsumption!
But let’s think about for a minute, our current food
system seems to be designed to waste, we need to change this! We need to
produce respecting our planet (including technological advancements) and the
people working to preserve it (e.g. agroecological farmers, sustainable
fishers). It sounds reasonable, don’t you think?
Changes might not be done in the twinkling of an eye,
but if we start at home (paying attention to what we buy, from who we buy, at
what price, buying seasonally, locally and only what we are going to eat and support
the work of farmers producing taking care of the ecosystem (at home or abroad)
and politicians willing to take actions in their favor) and talk about it, soon
we will be more until we become the majority. .Then, the industry that wants to
sell will sell what we want.
Things can change if we really want them to change. We,
as individuals, can make the difference, we are already doing it!
But to change, we need to get informed and understand how things work and
what is good for our health which is not disconnected from what is good for our
society and our planet.
A healthy diet is a diet that must satisfy energy
needs (proteins, fats, carbohydrates) and essential nutrients (vitamins and
minerals) through food, to attain and maintain optimal health and physiological
Importantly, our bodies need energy (energy
requirement) for a series of functions that are essential for life or basal
metabolism (e.g. heart beating, respiration, brain activity, cell function and
replacement; synthesis, secretion and metabolism of enzymes and hormones, or
everything that our smart bodies do on their own), to process food and to perform
physical activity. Additionally, at some stages of our lives we need more energy, to
allow growth and development during childhood, deposition of tissue during
pregnancy and the secretion of milk during lactation.11
So, every day and depending on our body needs (age,
gender, body size, body composition, metabolism and physical activity), we need
to achieve an energy balance. This happens when the dietary energy intake (what
we eat) is equal to the total energy expenditure (what the body consumes).11
Malnutrition occurs when, at long term, the energy balance is not
reached (either too much or too little)
and/or there is a deficiency of nutrients.
Sources of energy
Fats and carbohydrates are the main sources of dietary
energy, though proteins also provide important amounts of energy, especially
when total dietary energy intake is limited.11
Current energy recommendations for a healthy diet
suggest a distribution of proteins, fats, and carbohydrates are in the range of
15, 29 and 55 percent daily (conversion factor of 4, 9 and 4 kilocalories per
gram (kcal/g) for proteins, fats and carbohydrates).12 Meaning that, if an adult consumes 2000 kcal/day as commonly recommended, the
energy intake should be divided in 300 kcal coming from proteins, 580 kcal from
fats and 1100 kcal from carbohydrates (or 75 g, 64 g and 275 g) daily.
Additionally, dietary fiber (ca. 2% daily requirement)12 is very important for a healthy diet as it interacts with the gut’s microbiome
maintaining or improving the microbiota. In recent years, the awareness about
the importance of human microbiota (microorganism within our body) has increased.
We will talk more about this topic. Stay tuned!
We need quality and diverse food that provides energy, vitamins and
minerals needed to live in a healthy way!
It’s worth noting that the values recommended for
daily energy requirements are used as a matter of convention and convenience as
they represent an average of energy needs over certain period of time and that
there is a large inter-individual variation.11 So, if we considering
the average energy value for everybody (e.g. 2000 kcal), some people could be
eating either too much or too little.
It is possible to calculate individual energy
requirements12, soon we will perform an exercise to share it with
you, don’t miss it!
The Best Diet
There is misunderstanding about the exact components
of a healthy diet, and many diets considered to be healthy.
The confusion is probably because the scientific
information available is misleading. Many studies have been based only on
individual nutrient (e.g. fats, carbohydrates), others have been sponsored by
companies which comprises the accuracy of the conclusions, and a lot of
knowledge has been spread without really understanding the long-term benefits.
To clarify these misunderstandings, it would help if
scientific studies would focus on nutrients in the context of food, food in the
context of diet and diet in the context of lifestyle.
Common sense about diet is not common yet!
Luckily, it seems like most recognized diets have a
lot in common. This is the outcome of the True Health Initiative, a global community with more than 400 world-renowned health experts. The
initiative evaluates scientific information and spread fundamental evidence and
consensus-based truths about lifestyle as medicine.
What do most recognized diets recommend?
(true food). Not too much. Mostly plants”…
And drink mostly water with it!13
In essence, most diets recommend meals rich in
vegetables, fruits, beans, lentils, nuts, whole grains, seeds with or without
other elements such as dairy, eggs, meat (consumed in small portions), and
prevailing quality over quantity.
Seems easy, right? But, what is true food?
True food refers to food that grows in nature (fruits,
vegetable, grains, seeds, nuts, etc.), minimally
processed (traditionally or innovatively transformed/conserved (e.g. bread,
cheese, yogurt or under vacuum); the less additives the better and even better
if they are all natural), sustainable
(produced on healthy soil using clean water, respecting the environment and
conserving biodiversity), and ethically
produced (towards humans and animals).
The production of true food treats the environment, plants, animals and
people with respect avoiding intensification (that requires the use of
chemical fertilizers, pesticides and antibiotics) and exploitation.
However, this is not the way most food is produced. The cost of this food is cheap for the
consumer but comes at a very high price for the farmers and the environment. It destroys our society, our planet and our
health because at the end, it is all connected!
If we care about consuming true food, we support not
only a healthy way of eating but we also build a community that shares values
of respect towards nature and humans beings.
In post 2 we talked about food as a good and the environmental connotation of its production. But, food is much more, once it is prepared and placed in the table, it connects us, brings emotion and joy to our life and at the same time it nourishes us!
Food is meant to be enjoyed! Pleasure is good for our health.
If we think about it, people having fun tend to be healthier.
Lifestyle as Medicine
Nowadays, there is a general consensus that health
needs to be approach in a holistic way – meaning that food is very important
for health but not less important than physical activity, sleep, happiness, low
levels of stress and good social interactions. Lifestyle as medicine is not
only important for disease prevention but also improves the outcome of many
On this regard and remarking on the importance of
healthy diets have a look to the YouTube video What is the best diet? with Dr. Mike Evans from the Reframe Health Lab. Many nice
videos on his website that are really worth watching!
Many factors influence our health – and a very
important one is what we eat.
It is important to eat in a sustainable manner,
prevailing quality over quantity, thinking of our health and our planet, respecting
all living beings, and safeguarding local food traditions and biodiversity!!
Let’s remember that changes in the food system can
come either from above (e.g. politics-related work, activism) or from below (e.g.
food demand, health literacy, label reading ability).
The industry produces what the consumer wants! So, we,
the consumers, are able to change things if we really want!
We can start caring about what we eat in an active way. Let’s prepare our own food.Let’s start cooking!!