Interactions between bacterial and fungal populations in a microbiome would be useful to predict outcomes from alterations in microbial community structures under a given physiological condition.
29 The present study confirms earlier studies that indicated that interactions between bacteria and fungi
19,30 in the gut microbiome of healthy individuals were either positive or negative, and in most cases the interaction appeared to be functionally relevant. For instance, in the present study, in HC microbiome
Dialister, an SCFA producer, negatively interacted (i.e., inhibited) with pathogenic
Escherichia,
Shigella,
Sutterella,
Coprinopsis,
48 and
Chlorophyllum, a mushroom.
Dialister, also inhibited
Mortierella, which has anti-inflammatory properties. It was also observed that
Gibberella, a plant pathogen that was the biggest hub, also interacted negatively with many pathogenic fungi (like
Marasmius,
Malassezia,
Lasiodiplodia,
Coprinopsis,
Volvariella, etc.) and bacteria (
Desulfovibrio,
Streptococcus,
Slackia, and
Collinsella).
Oscillospira, the other major hub in HC network, is a probiotic organism that showed negative interaction with pathogens like
Slackia,
Penicillium,
Gemella, and
Fusobacterium.
49 Another major hub was
Prevotella, which interacted negatively with microbes that functionally could be characterized as pathogens (
Treponema,
Rothia,
Clostridium,
Atopobium), anti-inflammatory (
Bifidobacterium,
Clostridium,
Bacteroides,
Butyricimonas,
Anaerostipes), and probiotic (
Bifidobacterium,
Veillonella, and
Bacteroides). It would appear that the majority of the interactions were directed toward controlling the dominance of pathogenic microbes in the HC gut microbiome and this is anticipated. In HC microbiome, we also observed that certain bacteria like
Oscillospira, a probiotic organism, negatively interacted with butyrate, producing
Butyricicoccus and
Anaerostipes;
Dialister, an SCFA producer, inhibited
Mortierella, which has anti-inflammatory properties; and
Prevotella interacted negatively with anti-inflammatory and probiotic microorganisms. Such interactions are not on anticipatory lines and are difficult to interpret.