Gut microbes that digest cellulose are declining, especially in industrialised nations

Subject: Science and tech

Section: Health

Context:

A recent study, published in the journal Science, highlights the link between the increasing consumption of processed food and the decline in gut bacteria capable of digesting plant cellulose, particularly in industrialized countries.
The research revealed three new species of cellulose-digesting bacteria in the human gut, previously abundant in rural populations, ancient human societies, and great apes, but now diminished due to dietary changes.

Key Findings:

The study identified three new gut bacteria species – Candidatus Ruminococcus primaciens, Ruminococcus hominiciens, and Ruminococcus ruminiciens – which can digest cellulose, a crucial component of plant fibre.
The decline of these bacteria affects energy balance and various health aspects since these microbes transform indigestible plant compounds into short-chain fatty acids, supplying energy to the host.
Previously thought absent in humans, cellulose-digesting microbes were first confirmed in 2003. The newly discovered species are less common in industrialized nations compared to their prevalence in ancient and rural populations.
Researchers analyzed samples from 75 animal species, including wild and domesticated animals and various human cohorts, using known strains Ruminococcus champanellensis and Ruminococcus flavefaciens as references to identify related species.
The study found significant differences in the prevalence of cellulose-degrading bacteria across populations, correlating these differences with dietary fiber intake. Rural and ancient populations, with higher fiber diets, showed greater prevalence compared to those in industrialized countries, where processed food consumption is higher.

Significance of the study findings:

This research underscores the profound impact of dietary choices on gut microbiota and, consequently, on human health.
The decline of cellulose-digesting bacteria in people from industrialized countries, due to lower dietary fiber intake, suggests a shift away from diets that support a diverse and healthy gut microbiome.

Source: DTE