IgA/IgM responses to gram-negative bacteria are not associated with perinatal depression, but with physio-somatic symptoms and activation of the tryptophan catabolite pathway at the end of term and postnatal anxiety

Background: Evidence has implicated the translocation of commensal Gram-negative bacteria (Gram-B) due to leaky gut in the pathophysiology of depression and physio-somatic symptoms (e.g. fatigue, pain, irritable bowel syndrome, malaise, etc.). In addition, the leaky gut may contribute to immune-inflammatory activation and oxidative stress. This study investigated whether bacterial translocation is associated with perinatal depression and anxiety scores and with prenatal physio-somatic symptoms and immune-inflammatory biomarkers, including the tryptophan catabolite (TRYCAT) pathway. Method: Data were collected in pregnant women at the end of term (T1) and 4-6 weeks after delivery (T2) as well as in non-pregnant controls. We examined the associations between serum IgM/IgA responses to Gram-B at the end of term and depression (Edinburgh Postnatal Depression Scale -EPDS) and anxiety (Spielberger’s State Anxiety Inventory -STAI) symptoms. Results: Levels of C-reactive protein, zinc, haptoglobin, hematocrit and IgA/IgM responses to 9 TRY-CATs were also measured. No significant associations of the IgA/IgM responses to Gram-B with prenatal depression and anxiety were observed. Increased IgA/IgM responses to Gram-B predict higher levels of haptoglobin, hematocrit and TRYCATs, in particular quinolinic acid and the quinolinic acid/kynurenic acid ratio. IgA responses to Gram-B were significantly lowered in pregnant women compared to age-matched non-pregnant women, while IgM responses were significantly elevated in participants with alcohol consumption. Physio-somatic symptoms at the end of term were significantly associated with IgM responses to Klebsiella pneumonia. Postnatal anxiety was significantly predicted by IgA responses to Pseudomonas aeruginosa. Conclusions: Our findings suggest that pregnancy may protect against bacterial translocation, while alcohol use may increase bacterial translocation. The results suggest that end of term mucosa-derived immune responses to Gram-B contribute to immune activation, physio-somatic symptoms at the end of term and postnatal anxiety. Highlights: • Immune responses to Gram - Bacteria associate with physio-somatic symptoms in pregnancy. • IgA responses to Pseudomonas aeruginosa predict anxiety symptoms after delivery. • Pregnancy may have a protective effect against bacterial translocation. • Alcohol use increases leaky gut and bacterial translocation

IgA/IgM responses to tryptophan and tryptophan catabolites (TRYCATs) are differently associated with prenatal depression, physio-somatic symptoms at the end of term and premenstrual syndrome

There is some evidence that lowered tryptophan and an activated tryptophan catabolite (TRYCAT) pathway play a role in depression, somatoform disorder, and postpartum blues. The aim of this study is to delineate the associations between the TRYCAT pathway and premenstrual syndrome (PMS) and perinatal depressive and physio-somatic symptoms. We examine the associations between end of term serum IgM and IgA responses to tryptophan and 9 TRYCATs in relation to zinc, C-reactive protein (CRP), and haptoglobin and prenatal physio-somatic (previously known as psychosomatic) symptoms (fatigue, back pain, muscle pain, dyspepsia, obstipation) and prenatal and postnatal depression and anxiety symptoms as measured using the Edinburgh Postnatal Depression Scale (EPDS), Hamilton Depression Rating Scale (HAMD), and Spielberger’s State Anxiety Inventory (STAI). We included pregnant females with (n = 24) and without depression (n = 25) and 24 non-pregnant females. There were no significant associations between the IgA/IgM responses to tryptophan and TRYCATs and prenatal and postnatal depression/anxiety symptoms, except for lowered IgA responses to anthranilic acid in prenatal depression. A large part of the variance in IgA responses to most TRYCATs was explained by PMS and haptoglobin (positively) and CRP (inversely) levels. The IgA responses to TRYCATs were significantly increased in PMS, in particular picolinic, anthranilic, xanthurenic and kynurenic acid, and 3OH-kynurenine. Variance (62.5%) in physio-somatic symptoms at the end of term was explained by PMS, previous depressions, zinc (inversely), CRP and haptoglobin (both positively), and the IgM responses to quinolinic acid (positively), anthranilic acid, and tryptophan (both negatively). The results suggest that mucosa-derived TRYCAT pathway activation is significantly associated with PMS, but not with perinatal depression/anxiety symptoms. Physio-somatic symptoms in pregnancy have an immune-inflammatory pathophysiology. Induction of the TRYCAT pathway appears to be more related to physio-somatic than to depression symptoms