Changes in the rodent gut microbiome following chronic restraint stress and low-intensity rTMS

Abstract

Gut microbiome composition is associated with mood-relating behaviours, including those reflecting depression-like phenotypes. Repetitive transcranial magnetic stimulation (rTMS), a non-invasive neuromodulation technique, is an effective treatment for depression, but its effects on the gut microbiome remain largely unknown. This study assessed microbial changes from rat faecal samples longitudinally following chronic restraint stress (CRS) and 10 Hz low-intensity rTMS treatment. CRS increased abundance within the Proteobacteria (Deltaproteobacteria, Desulfovibrionales) and Firmicutes ( Anaerostipes, Frinsingococcus ) , with decreases in Firmicutes family (Acidaminococcaceae) and genera ( Roseburia , Phascolarctobacterium and Fusicatenibacter ) persisting for up to 4 weeks post CRS. The decrease in Firmicutes was not observed in the handling control and LI-rTMS groups, suggesting that handling alone may have sustained changes in gut microbiome associated with CRS. Nonetheless, LI-rTMS was specifically associated with an increase in Roseburia genus that developed 2 weeks after treatment, and the abundance of both Roseburia and Fusicatenibacter genera was significantly correlated with rTMS behavioural and MRI outcomes. In addition, LI-rTMS treated rats had a reduction in apoptosis pathways and several indicators of reduced inflammatory processes. These findings provide evidence that the brain can influence the gut microbiome in a “top-down” manner, presumably via stimulation of descending pathways, and/or indirectly via behavioural modification.

The gut-microbiota-brain axis in a Spanish population in the aftermath of the COVID-19 pandemic: microbiota composition linked to anxiety, trauma, and depression profiles

“…Higher levels of childhood trauma were associated with an increased relative abundance of Anaerostipes . This finding correlates with data from rodent models; one model of early-life stress (ELS) 66 also detected higher levels of Anaerostipes following ELS exposure 67 and another detected higher levels of Anaerostipes in response to chronic restrained stress, 68 suggesting a causal effect of trauma on the abundance of Anaerostipes . Furthermore, a higher abundance of Anaerostipes has been observed in MDD patients 69 and individuals with low mood.…”

Are neuromodulation interventions associated with changes in the gut microbiota? A systematic review

“…The included studies were performed among both humans and animals, assessing different types of neuromodulation interventions (i.e., ECT (Kanayama et al, 2019), tDCS (Artifon et al, 2020), dTMS (Ferrulli et al, 2021), rTMS (Seewoo et al, 2022), DBS (Lubomski et al, 2022), VNS (Phillips Campbell et al, 2016;Haney et al, 2018) in a variety of diseases (i.e., schizophrenia (Kanayama et al, 2019), overweight and sugary food cravings (Artifon et al, 2020), obesity (Ferrulli et al, 2021), PD (Lubomski et al, 2022) and disease models (i.e., amyotrophic lateral sclerosis (Haney et al, 2018), heart failure (Phillips Campbell et al, 2016), depression (Seewoo et al, 2022) (see Table 1). Neuromodulation protocols generally consisted of multiple sessions of stimulation, ranging from 14 to 30 sessions over a period of 2-10 weeks, or chronic stimulation provided for 4 to 6 several weeks, except for Haney et al (2018) which administered VNS in a single session of 1 h (Haney et al, 2018).…”

“…Two studies reported that no antibiotics and/or probiotics were used prior to fecal sample collection and/or during the study (Ferrulli et al, 2021;Lubomski et al, 2022). Five studies reported about dietary habits and food intake (Kanayama et al, 2019;Ferrulli et al, 2021;Seewoo et al, 2022;Lubomski et al, 2022;Phillips Campbell et al, 2016).…”

“…The case study by Artifon et al (2020) was judged with a high risk of bias on six items and a low risk of bias on two items. Regarding the three animal studies, two (Seewoo et al, 2022;Haney et al, 2018) were judged with a low risk of bias in eight out of ten domains and with an unclear risk of bias on the remaining domains. The other (Phillips Campbell et al, 2016) was judged with a low risk of bias in all ten domains.…”

Probiotics (Bacillus clausii and Lactobacillus fermentum NMCC-14) Ameliorate Stress Behavior in Mice by Increasing Monoamine Levels and mRNA Expression of Dopamine Receptors (D1 and D2) and Synaptophysin

“…Restraint or immobilization is a widely used and accepted model to study stress and depression in animals ( Paré and Glavin, 1986 ; Liang et al, 2015 ; Seewoo et al, 2022 ). Restrainers (polyvinyl chloride, 50 ml syringe ventilated from the front by producing small vents) were used to induce stress in mice through previously reported protocols ( Paré and Glavin, 1986 ; Zafir and Banu, 2009 ).…”