Does Soil Contribute to the Human Gut Microbiome? Yes.
You are what you eat and, as you may or may not be aware right now, your gut microbiome is a major factor in your health and welness. It disgest our food, creates resilence and strength in our bodies as well as fights disease making compounds. It is connected with everything we do and need from our malabsorption issues, our immune system harmony and our breath.
The human gut microbiome is more diverse than soil microbiome, but there is less diversity in the human gut than in soil. People in urban areas have more differentiated individual microbiomes.
Soil is consumed as a supplement to a nutrient-poor diet, and soil microbiota has been used as a detoxifying agent in the production of foods for humans.
The human microbiome is a field of biomedical research that has become a major field of biomedical research. The human microbiome is subject to a constant influx of microbial colonizers.
Human activities may affect soil microbes and the human microbiome. Therefore, the potential relationship between the soil microbiome and the human microbiome is explored.
Soils are a natural microbial gene reservoir on earth and may affect the human intestinal microbiome.
Since 2010, the Earth Microbiome Project has focused on studying the microbial life on Earth. You can watch short animations showing your the life in the soil food web.
On a per gram basis, human gut has the most diverse populations of any environment. However, soils are a factor of 10 less diverse than the human gut, as 80% of soil cells are dormant.
Human-associated intestinal microbial communities are more similar to one another than to those of other mammalian species; this is a result of an ongoing coevolution between the microbial communities and their hosts.
Mammalian microbiomes have diverged over 75 million years due to the loss of bacterial species. Humans and other primates are omnivores, whose diets include fruit, and apes and bonobos are herbivores.
The microbiota of the human gut derived from the ancestors, from the mother, and from the maternal body sites after birth, and from the ancestors through vertical transmission, including the maternal gut.
GI microbiota can regulate host genes, thereby regulating energy expenditure and storage. It is suggested that dietary intake has stronger influence on gut microbial composition than host genetics.
Contact with soil plays a role in both short-term as well as long-term changes of the microbiome.
Despite the fact that modern hygiene, antibiotics, and modern agricultural practices have contributed tremendously to a major reduction in human disease burdens and mortality, the loss of contact with outdoor-associated natural beneficial microbiota indirectly affects the human gut microbiome and may have negative consequences on human health.
Mice that are exposed to soil microbes have a more diverse gut microbiome than mice that are exposed to sterile soil, and the latter is unaffected by sterile soil.
Mammals, especially horses, have less diverse gut microbiomes compared to undomesticated species, and this holds true for zoo animals. Soil has the strongest influence on baboons’ gut microbiota.
The close link between soil biodiversity and gut microbiota in baboons is important in the global megatrend of biodiversity loss. This link deserves critical scrutiny given the effects of changes in human lifestyle.
Human feces are recycled today as animal manure, which is beneficial for the soil microbiota.
Intensifying urbanization, industrialization and agriculture practices are reducing soil biodiversity, reducing contact with the natural environment and decreasing gut microbiota richness.
Rural societies show a higher diversity of bacterial species in the gut, while urban communities show lower diversity.
Martnez and colleagues [54] proposed that in rural populations, the gut microbiome is likely to be less varied than in urban populations. This may be explained by low microbial dispersal in urban populations.
Modern hygiene measures reduce pathogen transmission, which reduces the number of species in Western populations.
The prevention of fecal contamination of water resources poses a significant risk to human health. Several techniques exist to reduce the risk of infection with intestinal pathogens.
Soil has many ecological functions, one of which is to provide clean drinking water through the infiltration capacity of soil structures. This is enhanced by soil biodiversity.
Urban citizens lose contact with soil, animal feces and soil. Infants who are born vaginally and explore the environment with their mouths gain a higher proportion of fecal microbiota from their mothers.
The urban environment is a habitat for pathogens. Communalists and pathogens can stimulate the immune system.
Biodiverse areas are associated with improved health, including urban re-wilding that improves contact with a diverse set of environmental microbiota.
Urban environments and lifestyle changes in humans cause interruptions in the microbiological cycle that are necessary for a healthy intestinal microbiome.
Our diet has changed because food is more processed and sterilized, and we eat more energy-rich food, and this results in the loss of biodiversity in our intestines.
The intake of medication drives the gut microbiome of Western populations; the increase of antibiotics and meat consumption, as well as the horizontal transfer of antibiotic resistant genes, have led to antibiotic resistance and environmental problems.
The most influential factors on the composition of the fecal microbiome are stool consistency and oral medication.
The study of Martinez et al. [54] supports the hypothesis that a diet rich in plant derived carbohydrates and fibers is more relevant for shaping the human gut microbiome than antibiotics.
The gut microbiome of hunters in Tanzania showed a low proportion of Bifidobacteria compared to the gut microbiome of Western civilization due to dietary habits of dairy and meat consumption.
Microbiomes of non-Westernized populations resemble the microbiomes of vegetarians and vegans, and show higher proportions of glutamate synthase gene than the microbiome of US citizens.
In a Danish study, specific types of food were identified as relevant for shaping the gut microbiome, including fruit, bread, and alcohol consumption. The human intestinal microbiome can be directly affected by the diet.
Human food production processes include several post-harvesting operations before consumption (Figure 1), but soil biodiversity can help to reduce these operations. This is because symbiotic microbes increase the nutritional quality of crops, and the plants also produce secondary plant metabolites.
Fresh fruit eaten unprocessed is beneficial for human health because of the secondary metabolite production.
Large scale farms use agrochemicals to optimize yields, and this reduces the variety of foods for humans. Organic vegetables are higher in biodiversity than conventionally grown vegetables.
The human gut microbiome is negatively affected by antibiotic medication.
Soil is highly diverse and soil microbes vary by region. In particular, soil microbes are highly diverse by region.
There is little overlap between soil and gut microbes at lower taxonomic levels, but there are fundamental differences between the two habitats. Soil is a medium limited in carbon and energy, whereas human fecal samples were dominated by Bacteriodetes and Firmicutes phyla.
Plant rhizospheres and the human gut microbiome have many phylogenetic similarities and many functional similarities. Both systems provide protection against pathogens and modulate the immune system and both are open systems with large surface areas overpopulated with microbes.
We need to understand the major drivers of rhizosphere biodiversity: soil type, moisture, age, plant genotype, and root hairs and exudates. Extensive tillage of soils and hydroponics are the most important drivers for rhizosphere biodiversity.
Biofilms are found in many environments, including the GI tract of humans and the soil rhizosphere.
The gut microbiota and the root microbiota are important for the health and performance of the host.
Micronutrient deficiency in humans, arising from nutrient-depleted soils, has direct and indirect effects on soil ecosystems.
Urbanization and mechanization of agriculture have drastically increased worldwide, but the use of antibiotics and hormones has reduced soil biodiversity.
Similar to the human gut microbiome, the soil rhizosphere also interacts with the human gut.
Recent research indicates that the human microbiome is shaped by the modern lifestyle/environment. Soil (rhizosphere) microbes clearly influence the quality and storage of our food.
Recent findings suggest the consumption of mostly unprocessed organic products and the consumption of wild relatives of crop varieties with high yields may have benefits for human health.
Rich soil microbiomes would increase plant nutrient uptake and may improve plant yields. They may also help to improve plant resistance and resilience to biotic stressors.
The soil contributes to the human gut microbiota. A reduction in soil contact in recent decades leads to the depletion of the human gut microbiota, which in turn affects human health.
Abstract
Soil and the human gut contain approximately the same number of active microorganisms, while human gut microbiome diversity is only 10% that of soil biodiversity and has decreased dramatically with the modern lifestyle. We tracked relationships between the soil microbiome and the human intestinal microbiome. We propose a novel environmental microbiome hypothesis, which implies that a close linkage between the soil microbiome and the human intestinal microbiome has evolved during evolution and is still developing. From hunter-gatherers to an urbanized society, the human gut has lost alpha diversity. Interestingly, beta diversity has increased, meaning that people in urban areas have more differentiated individual microbiomes. On top of little contact with soil and feces, hygienic measures, antibiotics and a low fiber diet of processed food have led to a loss of beneficial microbes. At the same time, loss of soil biodiversity is observed in many rural areas. The increasing use of agrochemicals, low plant biodiversity and rigorous soil management practices have a negative effect on the biodiversity of crop epiphytes and endophytes. These developments concur with an increase in lifestyle diseases related to the human intestinal microbiome. We point out the interference with the microbial cycle of urban human environments versus pre-industrial rural environments. In order to correct these interferences, it may be useful to adopt a different perspective and to consider the human intestinal microbiome as well as the soil/root microbiome as ‘superorganisms’ which, by close contact, replenish each other with inoculants, genes and growth-sustaining molecules.
Read full article here.
References
Blum WEH, Zechmeister-Boltenstern S, Keiblinger KM. Does Soil Contribute to the Human Gut Microbiome? Microorganisms. 2019; 7(9):287. https://doi.org/10.3390/microorganisms7090287
