Pesticide exposure puts our organs at risk

Microbiota-gut-brain axis: how is the axis altered by exposure to pesticides?

by Lorenzo Ciotti
Pesticide exposure puts our organs at risk
© Getty Images / Handout

Pesticides are dangerous because of the presence of residues in food due to regulations, perhaps excessive, in trade, which lead to the widespread and preventive use of pesticides. Furthermore, although pesticides are not the only cause responsible for ecological damage, they are certainly one of the most serious. This danger was long ignored until the fears became dramatically evident. Disappearance of animal species, disappearance of fish in rivers and seas near the coasts, reduction of game, especially birds, contamination of water and land up to the polar regions: a profound alteration of the environmental balance.

Furthermore, harmful organisms that develop in the field at the expense of crops, both directly and indirectly, take away from man, it is estimated, about a quarter of global production. However, this estimate does not consider other important organisms that deplete human food sources, such as storehouse insects, phytophagous mites, agricultural nematodes, molluscs, and rodent mammals. Total erosion due to all harmful organisms is around the impressive percentage of 35%. An example, referring to rice, a staple food for over three billion people, highlights losses due to the concomitant action of insects, pathogens and weeds, in Asia it would be around 55% of the total product.

Pesticide© Sean Gallup / Staff Getty Images

The study Pesticide exposure and the microbiota-gut-brain axis, published on the The ISME journal, has studied an interesting retrospective on the issue related to the pesticide effect on human health.

The researchers explain: "The gut microbiota exists within a dynamic ecosystem shaped by various factors that include exposure to xenobiotics such as pesticides. It is widely believed that the gut microbiota plays an essential role in maintaining host health, including a significant influence on the brain and behavior. Given the widespread use of pesticides in modern agricultural practices, it is important to evaluate the long-term side effects that these xenobiotic exposures have on the composition and function of the gut microbiota. Indeed, exposure studies using animal models have shown that pesticides can induce negative impacts on the gut microbiota, physiology, and health of the host.

In parallel, there is a growing body of literature demonstrating that the effects of pesticide exposure can be extended to the manifestation of behavioral impairments in the host. With the growing awareness of the microbiota-gut-brain axis, in this review we evaluate whether pesticide-induced changes in the compositional profiles and functions of the gut microbiota could drive these behavioral alterations. Currently, diversity in pesticide type, exposure dose, and variation in experimental designs hinders direct comparisons of the presented studies. Despite the many insights presented, the mechanistic connection between the gut microbiota and behavioral changes remains insufficiently explored. Future experiments should therefore focus on causal mechanisms to examine the gut microbiota as a mediator of behavioral deficits observed in the host following pesticide exposure."