Impact of glyphosate on gut microbiota and the brain a cause for concern
Dysbiosis, mood disorders, neurodegenerative diseases, psychomotor disorders... According to a summary published by Polish researchers, the potential effects of glyphosate exposure are far from negligible
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Riddle me this: I’m the most widely used herbicide in the world. I’m considered a probable carcinogen by the WHO. Yet I’ve just been re-approved in Europe for ten years. Who am I?
Answer: Glyphosate.
If you knew the answer, congratulations! However, these three pieces of information are only scratching the surface for
(sidenote:
Glyphosate
Glyphosate is the active compound in Roundup, a “broad-spectrum” weedkiller introduced by Monsanto in 1974. It kills all weeds by blocking the EPSPS enzyme, which is involved in the synthesis of certain amino acids essential to their growth. Extremely effective, easy to use, and inexpensive, glyphosate is the most widely used pesticide in the world. It is considered a probable human carcinogen by the International Agency for Research on Cancer (IARC) and is also thought to be an endocrine disruptor (although this remains controversial). Since 2000, when its patent expired, it has been used in a large number of agricultural herbicides. In several countries, including France, the Netherlands, and Belgium, it is banned for private use and in public spaces.
Source: Muséum d’Histoire Naturelle and Inrae
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, a compound now found everywhere, whether in water, the air, or the food we eat, particularly cereals and legumes. 1
According to a review of studies into the consequences of exposure to glyphosate and the herbicides that contain it, the compound’s effects on the microbiota and brain are “devastating.” 2
Gut bacteria severely disturbed
For example, several studies on animals show that even at low doses, glyphosate increases gut pathogenic bacteria, reduces beneficial bacteria, and strongly impacts the abundance of two major bacterial groups, Firmicutes and Bacteroidetes.
We know that maintaining an adequate Firmicutes-to-Bacteroidetes ratio is a key factor in microbiota balance, and that a variation in this ratio is a marker of (sidenote: Dysbiosis Generally defined as an alteration in the composition and function of the microbiota caused by a combination of environmental and individual-specific factors. Levy M, Kolodziejczyk AA, Thaiss CA, et al. Dysbiosis and the immune system. Nat Rev Immunol. 2017;17(4):219-232. ) , an imbalance involved in various disorders and diseases.
Glyphosate is also thought to strongly destabilize the gut-brain axis, which is known to influence our behavior, memory, and emotions, as well as our immunity and hormones. A number of studies suggest that, in both rodents and humans, exposure to this herbicide disrupts the gut bacteria involved in the gut-brain axis, particularly those that play a beneficial role against certain mood disorders.
Impact on the entire nervous system
But that’s not all. Glyphosate may also have a significant impact on the blood-brain barrier (the membrane that protects the brain) and could alter the formation and survival of neurons, as well as the transmission of nerve impulses. This could have significant consequences for:
- mental health: anxiety, depression, suicidal thoughts, etc.;
- cognitive and social abilities: memory impairment, abnormal social or exploratory behavior, etc.;
- locomotion: paralysis, psychomotor disorders, etc.;
- the risk of neurodegenerative diseases: Parkinson, Alzheimer or Huntington’s disease, multiple sclerosis, etc.
Neurological disorders
While this summary raises more questions than it answers, it underlines the fact that further work is required to accurately assess the health risks of exposure to glyphosate. Since glyphosate is currently still widely used in many countries, this represents a global public health issue.
