Gut microbiota and parasite dynamics in an Amazonian community undergoing urbanization in Colombia.

Bacterial families associated with non-processed diets were reduced in urban compared to rural Leticia.

• Lachnospiraceae, Spirochaetaceae, and Succinivibrionaceae were identified as families with lower abundance in the urban environment.
• These families are described as 'linked to non-processed diets.'
• The urban population is predominantly non-indigenous while the rural area is mostly indigenous, resulting in 'notable lifestyle differences between the two settings.'
• The study setting was Leticia, in the southern Colombian Amazon, comparing geographically proximate urban and rural communities.

Prevotellaceae showed significantly higher abundance in urban Leticia despite typically being associated with non-processed food consumption.

• Prevotellaceae is described as 'typically associated with non-processed food consumption' yet showed higher abundance in the urban environment.
• This finding was described as statistically significant.
• This pattern represents a notable exception to the general trend of non-processed diet-associated bacteria being lower in urban settings.

Soil-transmitted helminth (STH) infections were primarily detected in rural Leticia, while intestinal protozoa were ubiquitous in both rural and urban areas.

• STH infections were geographically concentrated in the rural setting.
• Intestinal protozoa showed a different distribution pattern, being present in both urban and rural environments.
• Both STHs and protozoa were analyzed alongside gut bacterial microbiota composition.
• The study investigated both intestinal protozoa and soil-transmitted helminths as part of the parasite dynamics analysis.

Both intestinal protozoa and soil-transmitted helminths were associated with higher gut bacterial richness and diversity.

• The association held for both parasite types examined: intestinal protozoa and STHs.
• The relationship was observed for both alpha diversity metrics of richness and diversity.
• This finding suggests that parasite presence correlates with a more diverse gut microbiome.

Microbial metabolic prediction analysis indicated differences in pathways related to unsaturated fatty acid production and aerobic respiration between rural and urban bacterial microbiomes.

• The analysis used microbial metabolic prediction methodology.
• Two specific pathway categories differed: unsaturated fatty acid production and aerobic respiration.
• The authors interpret these differences as suggesting 'a tendency toward changes in the urban microbiota that may lead to increased susceptibility to non-communicable chronic diseases.'

The study identified a reduction in gut bacterial diversity in the urban Amazon population consistent with urbanization-driven microbiota changes reported elsewhere.

• The broader context notes that urbanization drives microbiota changes through 'shifts toward processed diets, increased antibiotic usage, and improved sanitation practices.'
• The authors note this phenomenon 'has been largely overlooked in the Colombian Amazon, despite rapid urbanization in the region.'
• Changes in diversity and composition of gut microbiota in urban populations have been linked to non-communicable chronic diseases 'such as autoimmune conditions, diabetes, and cancer.'