Table 3 Microbial functional genes related to the metabolism of cholesterol and BA assigned (ratio 1/10,000 reads) through MetaCyc metabolic pathway database in three metagenomes from human bile and five fecal metagenomes from healthy subjects from a previous study [20]

Cholesterol biosynthesis I

0.13

0.02

0.29

0.00

0.00

0.00

0.08

0.00

0.15 ± 0.11

0.02 ± 0.03

Cholesterol biosynthesis II (via 24,25-dihydrolanosterol)

0.13

0.02

0.29

0.00

0.00

0.00

0.08

0.00

0.15 ± 0.11

0.02 ± 0.03

Cholesterol biosynthesis III (via desmosterol)

0.13

0.02

0.29

0.00

0.00

0.00

0.08

0.00

0.15 ± 0.11

0.02 ± 0.03

Superpathway of cholesterol biosynthesis

0.37

3.29

15.31

0.12

0.21

0.25

1.06

0.25

6.32 ± 6.47

0.38 ± 0.34

Superpathway of cholesterol degradation I (cholesterol oxidase)

1.06

0.17

0.21

0.41

0.46

0.39

0.48

0.71

0.48 ± 0.41

0.49 ± 0.11

Superpathway of cholesterol degradation II (cholesterol dehydrogenase)

1.52

0.34

0.36

0.54

0.5

0.47

0.62

0.81

0.74 ± 0.55

0.59 ± 0.12

Cholesterol degradation to androstenedione I (cholesterol oxidase)

0.35

0.02

0.07

0.00

0

0.00

0.01

0.02

0.15 ± 0.15

0.01 ± 0.01

Cholesterol degradation to androstenedione II (cholesterol dehydrogenase)

0.74

0.05

0.21

0.00

0.00

0.00

0.06

0.02

0.33 ± 0.29

0.02 ± 0.02

Bile acid biosynthesis, neutral pathway

0.61

0.07

0.29

0.06

0.06

0.02

0.11

0.05

0.32 ± 0.22

0.06 ± 0.03

Glycocholate metabolism (bacteria)

1.58

2.71

0.72

10.58

15.03

12.4

15.53

12.35

1.67 ± 0.81

13.18 ± 1.84

Cholate degradation (bacteria, anaerobic)

0.35

0.46

0.14

0.97

0.77

0.41

0.62

0.38

0.32 ± 0.13

0.63 ± 0.22