2. The diversity and intra-group heterogeneity of the VMB was
higher in PCOS patients
At
the genus level, the proportion of Lactobacillus reduced
(FDR<0.2) and the proportion of Gardnerella andUreaplasma increased in the PCOS group (FDR<0.2) (Figure 1a),
compared with the control
group.
At the species level, we found that U. parvum , G.
vaginalis , A. baumannii , P. buccalis ,P. timonensis , and P. acnes were more abundant in
the PCOS group, while the abundance of L. Jesenia ,L. iners, B. breve, and L. pontis were significantly
depleted (FDR<0.2) (Figure 1b).
The increase of the Shannon index
and decrease of the Simpson index indicated that the VMB in the PCOS
group had higher diversity than that of the control group
(P<0.05) (Figure 2a,2b). The Chao 1 index and Shannon index of
the PD subgroup was also higher than that of the control group
(P<0.05)(Figure 2c,2d). However, there was no significant
difference in diversity between the PA subgroup and the control group
(P>0.05). The PCoA analysis indicated that there was no
significant difference in the VMB structure between groups(Figure 3a,3b)
(P>0.05). PCOS group had higher intragroup variation
compared with control group (P<0.05) (Figure 3c)
We constructed a random forest model for PCOS. The feature confirmed by
the Boruta algorithm23 was selected as an important species for
classification accuracy. We could accurately distinguish PCOS patients
from healthy controls, as indicated by the area under the receiver
operating curve (AUC), which had a maximum value to 0.8 (Figure 4)
3. Correlations between VMB
and clinical indicators
A total of 35 bacterial species from an overlap set of differential
species between PCOS and controls and significant species in model of
random forest model were used to analyze the correlation with clinical
indicators. G. vaginalis was positively correlated with serum
level of AMH, E2, and P (p<0.05). AMH, LH and
T showed the highest positive correlation strength withU.parvum and A. baumannii , but a negative correlation
with Prevotella . In addition, HDL and TG levels were associated
with the abundance of L. acidophilus , P.buccali and U. parvum (Figure 5).
4. Lactobacillus crispatus and Prevotella
timonensis drove changes in PCOS vaginal microbiota co-occurrence
network
Two
networks were separately constructed for the PCOS and control groups.
The topology of the two networks were similar. In both groups module 1
and 2 mostly contained L. crispatus , and L.iners, which showed a negative correlation with each other
(Figure 6a,6b). The largest was module 3 in the two groups and was
mainly composed of potential vaginal pathogens, including G.
vaginalis, P. bivia, P. timonensis, P. amnii, P. buccalis,P. disiens, A. vaginae, D. micraerophilus, S. sanguinegens, and