Impact of humic acids on the colonic microbiome in healthy volunteers

Table 1 Mean microbial concentrations (± SD) as detected with applied fluorescence in situ hybridization probes (10⁹ bacteria/mL)

	Day 0	Day 10	Day 31	Day 45	Change in % from day 0 to day 45	P value
Mean sum concentrations of all detected bacteria	85.4 ± 25.6	107.4 ± 15.6	123.7 ± 34.1	126.1 ± 50.1	↑ 32%	< 0.001
Essential all (n = 3)	36.2 ± 14.7	44.0 ± 5.1	42.7 ± 7.7	42.8 ± 9.0	↑ 14%	< 0.01
Erec (Eubacterium rectale, Clostridium coccoides group)	11.7 ± 6.9	17.1 ± 2.5	19 ± 4	17.7 ± 4.8	↑ 30%	< 0.001
Bac303 (Bacteroides)	12.9 ± 5.3	12.2 ± 5.7	9.5 ± 4.4	9.9 ± 5.0	↓ 30%	ns
Fprau (Faecalibacterium prausnitzii)	11.6 ± 5.9	14.7 ± 3.8	14 ± 3.6	14.7 ± 6.9	↑ 21%	ns
Individual pioneer
All (n = 4)	7.8 ± 5.0	11.5 ± 9.3	9.9 ± 6.8	10.9 ± 8.5	↑ 28%	ns
Ebac1790 Enterobacteriaceae	0.25 ± 0.8	0.6 ± 2.1	1.2 ± 2.3	1.1 ± 2.0	↑ 72%	ns
Cdif198 Clostridium difficile	0.04 ± 0.09	0.01 ± 0.03	0.3 ± 0.93	0.10 ± 0.03	↑ 96%	ns
Bif153 Genus Bifidobacterium	7.1 ± 5.5	9.1 ± 8.6	7.7 ± 5.3	9.7 ± 7.2	↑ 27%	ns
Clit135 Clostridium lituseburense group including C. difficile	0.5 ± 0.86	0.7 ± 1.05	0.4 ± 1.08	0.4 ± 0.8	↔	ns
Individual substantial mean > 0.1 × 109/mL
All (n = 28)	41.7 ± 17.3	51.4 ± 14.0	70.4 ± 28.8	71.6 ± 36.8	↑ 41%	< 0.002
ACI623 Acidaminococcaceae sp. (not the Selenomonas species)	1.4 ± 1.9	0.7 ± 0.8	1.6 ± 2.2	1.2 ± 1.6	↔	ns
AKK406 Akkermansia	2.3 ± 3.7	2.8 ± 4.6	1.9 ± 2.9	2.6 ± 4.1	↔	ns
Ato291 Atopobium cluster	3.8 ± 2.9	4.9 ± 3.5	6.1 ± 4.5	6.4 ± 3.6	↑ 41%	0.01
Bbif186 B. bifidum	0.3 ± 0.9	0.3 ± 0.6	0.2 ± 0.5	0.3 ± 0.5	↔	ns
Blon1004 B. longum	0.7 ± 1.2	0.9 ± 1.5	1.0 ± 1.5	0.6 ± 0.9	↔	ns
Bputre698 Bacteroides putredinis	0.8 ± 1.6	0.8 ± 1.3	1.8 ± 2.1	1.6 ± 1.8	↑ 50%	ns
Burkho Burkholderia spp.	0.7 ± 0.7	1.4 ± 1.0	1.3 ± 1.4	1.3 ± 1.2	↑ 46%	0.01
Ceut705 C. eutactus, Coprococcus sp.	3.0 ± 4.4	4.5 ± 5.1	5.6 ± 6.7	4.1 ± 5.2	↑ 32%	ns
Chis150 Clostridium histolyticum	0.6 ± 1.2	1.4 ± 3.6	2.5 ± 4.5	1.5 ± 2.1	↑ 60%	ns
Cor653 Coriobacterium group	0.5 ± 0.8	0.8 ± 1.0	1.2 ± 2.2	1.2 ± 1.5	↑ 42%	ns
Cvir1414 Clostridium viride group	1.9 ± 2.1	3.4 ± 2.2	4.2 ± 2.5	4.0 ± 2.1	↑ 53%	< 0.001
Ecyl387 Eubacterium cylindroides	0.7 ± 0.5	0.7 ± 0.4	1.4 ± 1.1	1.2 ± 0.7	↑ 42%	0.01
Ehal1469 Eubacterium hallii	0.6 ± 0.9	0.6 ± 1.1	0.7 ± 0.8	0.7 ± 0.8	↔	ns
Eram997 Eubacterium ramulus	0.3 ± 1.3	0.03 ± 0.04	0.7 ± 1.4	1.0 ± 1.5	↑ 70%	ns
Lab158 Lactobacillus sp., Enterococcus sp.	0.1 ± 0.2	0.8 ± 1.1	1.7 ± 3.0	0.5 ± 0.9	↑ 80%	0.02
Muc1437 Akkermansia muciniphila	2.8 ± 3.9	1.8 ± 3.2	6.5 ± 7.4	7.8 ± 8.9	↑ 64%	0.015
Myc657 Mycobacterium subdivision (mycolic acid-containing Actinomycetes)	3.1 ± 1.5	2.5 ± 1.3	1.6 ± 1.1	1.9 ± 1.9	↓ 39%	ns
Phasco741 Phascolarctobacterium faecium	0.6 ± 0.9	0.9 ± 0.8	0.8 ± 0.8	1.1 ± 1.1	↑ 45%	ns
Pnig657 Prevotella nigrescens	2.2 ± 3.7	0.7 ± 1.3	2.6 ± 3.1	1.7 ± 2.3	↔	ns
ProCo1264 Ruminococcus productus	0.7 ± 2.0	1.5 ± 2.6	1.4 ± 2.3	1.9 ± 3.7	↑ 63%	ns
Rfla729 Ruminococcus albus	2.2 ± 3.2	5.5 ± 5.0	4.7 ± 5.0	3.9 ± 4.6	↑ 44%	0.02
SFB1 Segmented filame(14%ntous bacteria	2.3 ± 3.3	1.6 ± 2.7	2.3 ± 1.6	2.9 ± 1.9	↔	ns
SNA Sphaerotilus natans	4.3 ± 3.7	6.1 ± 5.4	6.8 ± 5.9	5.9 ± 5.8	↑ 27%	ns
Strc493 most Streptococcus spp.	1.3 ± 3.3	0.5 ± 1.1	1.9 ± 3.9	3.7 ± 4.9	↑ 65%	ns
SUBU1237 Burkholderia spp., Sutterella spp.	1.7 ± 2.6	3.4 ± 2.6	5.6 ± 4.4	5.6 ± 4.2	↑ 69%	0.001
Urobe63a Ruminococcus obeum-like	1.6 ± 2.3	2.2 ± 2.3	2.5 ± 2.9	3.2 ± 2.4	↑ 50%	0.05
Veil223 Veilonella	0.1 ± 0.3	0.1 ± 0.4	0.6 ± 1.4	0.9 ± 2.1	↑ 88%	ns
Ver620 Verrucomicrobium	1.7 ± 3.9	0.5 ± 1.6	1.1 ± 3.2	1.9 ± 5.3	↔	ns
Individual marginal or accidental mean 150 (n = 6)
Cperf191 Clostridium perfringens	0.001	0	0	0.001	↔	ns
Efaec Enterococcus faecalis	0.01 ± 0.02	0.01 ± 0.03	0.01 ± 0.02	0.01 ± 0.03	↔	ns
MIB724 mouse intestinal bacteria	0.01 ± 0.06	0.001 ± 0.002	0.01 ± 0.03	0.07 ± 0.1	↔	ns
Pce Burkholderia spp.	0.09 ± 0.30	0.03 ± 0.10	0.3 ± 0.7	0.07 ± 0.20	↔	ns
Rbro730 Clostridium sporosphaeroides, Ruminococcus bromii, Clostridium leptum	0.04 ± 0.20	0.08 ± 0.30	0.8 ± 3.0	0.1 ± 0.5	↑	ns
Urobe63b Ruminococcus obeum-like	0.01 ± 0.04	0.0001	0.001	0.6 ± 1.1	↔	ns