How microplastics affect gut health

Human stomach
How do microplastics affect the microbiome? (Getty Images)

How, and why, do microplastics alter the microbiome?

Microplastics, small particles of plastic less than five millimetres long, are, unfortunately, a significant part of many food and beverages.

They have been found in water bottles, seafood, table salt, fruits and vegetables such as apples and carrots, and even beer. Ingestion through food and beverage is one of the main ways, along with inhalation, that humans consume microplastics.

They can also cause negative health effects, and have in the past been linked to abdominal pain, nausea, and vomiting. Some research has even linked them to the spread of antimicrobial resistant bacteria.

A new review explores the research around how microplastics can also impact the gut.

Can microplastics harm gut health?

Gut health is one of the most prominent trends within the food industry at the moment. A wide range of products offer gut health benefits and a growing body of research suggests managing the gut is the key to many health outcomes.

The presence of microplastics could alter our gut health. According to the review, when microplastics accumulate in the gastrointestinal tract (where they can remain for a long time due to their resistance to digestion) this can lead to dysbiosis, an imbalance between beneficial and harmful (pathogenic) gut bacteria.

This imbalance has been linked to a range of health conditions, including weakened immunity, impaired gut function, and an increased risk of gastrointestinal disorders.

Gut dysbiosis may lead to inflammatory responses and increase gut permeability, leading to the condition often known as ‘leaky gut’. This can lead to the leakage of pathogens into circulation, potentially resulting in autoimmunity (where the body’s immune system attacks the body’s own tissues). Microplastics also exacerbate this through microabrasions in the gut lining. They may also carry chemicals such as heavy metals and persistent organic pollutants (POPs) which can further damage the gut lining.

Microplastics can disrupt the gut-heart axis and the gut-kidney access, important parts of heart and kidney health.

The presence of microplastics can also result in systemic inflammation, which in turn can lead to diabetes, obesity, and cardiovascular and autoimmune diseases. Inflammatory responses can disrupt insulin signalling pathways.

Microplastics have even been known to affect the gut-brain axis, leading to neurological and even psychological disorders. For example, it can lead to anxiety, depression, and cognitive decline. Dysbiosis can lead to a reduction in the production of short-chain fatty acids, which according to the review are crucial to brain health.

The microbiome is also, according to the review, central to energy homeostasis and nutrient metabolism, meaning that microplastics have the potential to lead to imbalances in energy storage and expenditure.

How can policy makers respond?

The researchers suggest that in order to combat the dangers that microplastics pose, governments and industry must collaborate.

For example, they must regulate plastic production and disposal more effectively, improve waste management, and develop alternatives to plastic such as biodegradable materials.

Microplastic levels in the air, water and food must be monitored, water must be filtered and air quality must be improved.

Sourced From: Frontiers

‘Microplastics and human health: unveiling the gut microbiome disruption and chronic disease risks’

Published on: 25 November 2024

DOI: 10.3389/fcimb.2024.1492759

Authors: S S Bora, R Gogoi, M Ranjan Sharma et al.