Table 4. Pairs of Han subgroups showing significant difference in bacterial quantity.

Sample pair showing significant difference	Bacterial family	Bonferroni-corrected p-value
Jiangsu - Henan	Desulfovibrio genus	0.0060
Heilongjiang - Jiangsu	Desulfovibrio genus	0.0027
Heilongjiang - Henan	Clostridium perfringens group	0.0098
Heilongjiang - Sichuan	Clostridium perfringens group	0.0002
Heilongjiang - Jiangsu	Clostridium perfringens group	0.0000
Heilongjiang - Sichuan	Bacteroides fragilis group	0.0249

Remark: Pairwise Mann-Whitney test was performed to evaluate the sample difference.