Features of gut microbiota and short-chain fatty acids in patients with first-episode depression and their relationship with the clinical symptoms

Abstract

ObjectiveTo compare the differences in gut microbiota and short-chain fatty acids (SCFAs; metabolites of gut microbiota) in the serum of patients with first-episode depression and the healthy population and to analyze the relationship between gut microbiota and metabolite SCFAs and the clinical symptoms of major depressive disorder (MDD).MethodsA total of 45 patients with first-episode depression and 22 healthy volunteers were chosen to complete relevant scale evaluations, and feces samples and venous blood samples were collected. The 16S RNA method was used to analyze the intestinal microflora and the characteristics of serum SCFAs detection by ELISA kit, as well as the intestinal flora, SCFAs content and their correlation with MDD clinical indicators.ResultsThe abundance of Akkermansia, Megamonas, Prevotellaceae NK3B31 group, and butyrate-producing bacteria, Lachnospira, Subdoligranulum, Blautia, and Dialister, and acetate-producing bacteria, Streptococcus, in the gut microbiota of the MDD group was lower than that in the control (C) group. The abundance of Parasutterella in the MDD group was higher than that in the C group. Dialister negatively correlated with all measured clinical symptoms (r < 0, P < 0.05). The serum SCFA content in the MDD group was higher than that in the C group, and the content positively correlated with the Hamilton anxiety scale scores (r = 0.584, P < 0.05).ConclusionThe results demonstrated that the MDD group differed from the C group in terms of gut microbiota and SCFAs in the serum and that the change in certain intestinal bacteria might participate in the pathogenic mechanism of MDD.

Alteration in gut microbiota is associated with immune imbalance in Graves’ disease

“…Such discrepancies can be attributed mainly to regional variations and clustering algorithm methodologies. Nonetheless, these genera are universally acknowledged as SCFA-producing microbes, and their decreased prevalence is observable in disorders like depression and atherosclerosis ( Yoshida et al., 2018 ; Yu et al., 2023 ). Moreover, these genera exhibited negative correlations with thyroid autoantibodies.…”

Mind, Mood and Microbiota—Gut–Brain Axis in Psychiatric Disorders

“…It was found that the MDD group had lower levels of certain gut microbiota, including Akkermansia , Megamonas , the Prevotellaceae NK3B31 group, butyrate-producing bacteria like Lachnospira , Subdoligranulum , Blautia , Dialister , and acetate-producing Streptococcus . This suggests that changes in these intestinal bacteria may be involved in the pathogenesis of MDD [ 61 ]. Additionally, SCFAs, particularly butyrate, acetate, and propionate, are known to possess histone deacetylase (HDAC) inhibitory activity, which leads to transcriptional activation by promoting euchromatin configuration, highlighting their role in epigenetic regulation [ 21 ].…”

Alterations in gut microbiota caused by major depressive disorder or a low FODMAP diet and where they overlap

“…The gut brain, along with the nervous system, HPA axis and immune system, can influence other organs to regulate both the brain and behavior ( 24 ). The proposed mechanism is through production of metabolites, particularly short chain fatty acids (SCFA) which are used to send signals to the brain via the blood stream ( 27 ). Studies of SCFA production in MDD patients reveal a reduction in butyrate and acetate producers ( 25 , 27 ).…”

“…The proposed mechanism is through production of metabolites, particularly short chain fatty acids (SCFA) which are used to send signals to the brain via the blood stream ( 27 ). Studies of SCFA production in MDD patients reveal a reduction in butyrate and acetate producers ( 25 , 27 ). Moreover, SCFAs can cross the blood brain barrier (BBB) and have a role in maintaining its integrity ( 28 ).…”

“…For example, immune dysregulation with chronic inflammation is thought to induce neuroinflammation ( 29 ). A reduction in butyrate producers may further compound this with butyrate having anti-inflammatory properties ( 27 ). Regulating gut microbiota can improve brain dysfunction and abnormalities of the immune system and HPA axis ( 24 ).…”