Global Microbiome: Core and Unique Signatures Across Diverse Populations.

Firmicutes, Bacteroidetes, and Proteobacteria constitute core phyla across all geographic regions analyzed.

• Analysis included 10,878 samples across North America, Europe, Africa, Asia, and Oceania
• 27 countries were represented in the dataset
• 16S rRNA gut microbiome sequencing data was used for all samples
• These three phyla were consistently identified regardless of geographic region

Lachnospiraceae was identified as a core family present across geographic regions, with differing predominance of other top families comprising unique regional microbiome signatures.

• Different regions showed distinct predominant families alongside the shared core family Lachnospiraceae
• Regional uniqueness was observed across North America, Europe, Africa, Asia, and Oceania
• Countries also differed in their relative abundances of Bifidobacterium, Faecalibacterium, Lactobacillus, and Bacteroides

Proteobacteria and Actinobacteria were the most abundant phyla in the youngest age group (neonate to age 17, AG01).

• Three age groups were analyzed: AG01 (neonate to age 17), AG02 (ages 18 to 64), and AG03 (age 65 and above)
• Proteobacteria and Actinobacteria predominance was specific to AG01 compared to older age groups
• This pattern was assessed across multiple continents

Actinobacteria abundance declined with increasing age across all continents.

• The decline in Actinobacteria was observed consistently across all continental regions studied
• The trend spanned all three age groups: AG01 (neonate–17), AG02 (18–64), and AG03 (65+)
• This represents one of the most consistent age-related microbiome patterns identified in the meta-analysis

The relative abundance of Bacteroidetes increased between the youngest age group (AG01) and the adult age group (AG02).

• AG01 comprised neonates through age 17; AG02 comprised ages 18 to 64
• This increase in Bacteroidetes was observed as part of age-related microbiome compositional shifts
• The pattern complements the finding of Proteobacteria and Actinobacteria predominance in AG01

Enrichment of asthma-associated Enterobacteriaceae in the youngest age group (AG01) was highest in North America, followed by Europe and then Asia.

• Enterobacteriaceae enrichment in AG01 was specifically noted in the context of asthma association
• A clear geographic gradient was observed: North America > Europe > Asia for this enrichment in AG01
• This finding was discussed in the context of clinical health trends including asthma prevalence

The meta-analysis systematically integrated heterogeneous gut microbiome studies using a standardized approach to enable cross-geographic and cross-age comparisons.

• Prior analyses were described as 'heterogeneous in methodology, precluding broader conclusions'
• The dataset spanned 27 countries and 5 continental regions: North America, Europe, Africa, Asia, and Oceania
• A total of 10,878 samples were included
• 16S rRNA sequencing data was used as the common methodological basis