Exploration of the gut microbiome in Thai patients with major depressive disorder uncovered a specific bacterial profile with depletion of theRuminococcusgenus as a putative biomarker

Abstract

Maes et al. (2008) published the first paper demonstrating that major depressive disorder (MDD) is accompanied by abnormalities in the microbiota-gut-brain axis, as evidenced by elevated serum IgM/IgA to lipopolysaccharides (LPS) of Gram-negative bacteria, such as Morganella morganii and Klebsiella Pneumoniae. The latter aberrations, which point to increased gut permeability (leaky gut), are linked to activated neuro-immune and oxidative pathways in MDD. To delineate the profile and composition of the gut microbiome in Thai patients with MDD, we examined fecal samples of 32 MDD patients and 37 controls using 16S rDNA sequencing and analyzed α- (Chao and Shannon indices) and β-diversity (Bray-Curtis dissimilarity) and conducted Linear discriminant analysis (LDA) Effect Size (LEfSe) analysis. Neither α- nor β-diversity differed significantly between MDD and controls. Rhodospirillaceae, Hungatella, Clostridium bolteae, Hungatella hathewayi, and Clostridium propionicum were significantly enriched in MDD, while Gracillibacteraceae family, Lutispora, and Ruminococcus genus, Ruminococcus callidus, Desulfovibrio piger, Coprococcus comes, and Gemmiger, were enriched in controls. Contradictory results have been reported for all these taxa, with the exception of Ruminococcus which is depleted in 6 different MDD studies (one study showed increased abundance), many medical disorders that show comorbidities with MDD, and animal MDD models. Our results may suggest a specific profile of compositional gut dysbiosis in Thai MDD patients with increases in some pathobionts and depletion of some beneficial microbiota. The results suggest that depletion of Ruminococcus may be a more universal biomarker of MDD that maybe contributes to increased enteral LPS load, LPS translocation, and gut-brain axis abnormalities.

Adverse childhood trauma and reoccurrence of illness impact the gut microbiome, which affects suicidal behaviors and the phenome of major depression: towards enterotypic-phenotypes

“…Two microbiota genera in enterotype 1 may have pathophysiological effects, in contrast. First, the Hungatella genera and H. hathewayi (as identified in our LefSe study, Maes et al, 2022c) are potential pathogens related to cardiovascular illness, Chrohn’s disease, and colorectal cancer (Kaur et al, 2014; Human Gut Microbiome Atlas, 2023). In addition, Hungatella is one of the genera that creates trimethylamine (TMA), a uremic toxin and precursor of trimethyl-N-oxide (TMAO), from choline, carnitine, and betaine present in meat, eggs, and shellfish (Genoni et al, 2020; Macpherson et al, 2020).…”

“…Two microbiota genera in enterotype 1 may have pathophysiological effects, in contrast. First, the Hungatella genera and H. hathewayi (as identified in our LefSe study, Maes et al, 2022c) are potential pathogens related to cardiovascular illness, Chrohn's disease, and colorectal cancer (Kaur et al, 2014;Human Gut Microbiome Atlas, 2023). In addition,…”

“…Stool sample collection, DNA extraction, 16S rDNA amplification and 16S rDNA amplicon sequencing based on Oxford Nanopore Technology (ONT) were performed as published previously (Maes et al, 2022c). Approximately 20 mg of stool was collected in sterile test tubes containing 2 mL of DNA/RNA ShieldTM reagent (ZYMO Research, USA) and stored at -20 degrees Celsius until analysis.…”

Exploring Microbial Signatures in Individuals with Prolactin-Secreting Pituitary Adenoma: Unraveling Microbiome Variations and Underlying Markers

“…In the NFPA group, the pathogen Morganella, a gram-negative bacterium belonging to Enterobacteriaceae, exhibited a disproportionately high abundance. This may lead to the suppression of the growth of SCFA-producing bacteria, contributing to immune and intestinal dysbiosis [33] . Moreover, the genus Blautia, known to in uence the development of CNS diseases by modulating in ammasome signaling pathways, thereby altering brain function, was highlighted [34] .…”