A randomized controlled trial to test the effect of multispecies probiotics on cognitive reactivity to sad mood

“The Beck Anxiety Inventory (BAI) (Beck et al., 1988) is a 21-item self-report questionnaire with high internal consistency (a = .90; Beck and Steer, 1993), which assesses the existence and severity of anxiety symptoms.”

“The probabilities range from with 0 (i.e., no evidence) to 1 (i.e., very strong evidence; see Raftery, 1995).”

“The Beck Depression Inventory II (BDI-II) (Beck et al., 1996) is a widely used 21-item multiple-choice self-report questionnaire with high internal consistency (a = .91; Beck et al., 1996), which assesses the existence and severity of current (past 2 weeks) depressive symptoms.”

“On the basis of these and other results it has been suggested that probiotics may serve as adjuvant or preventive therapy for depression (for reviews see Logan and Katzman, 2005; Cryan and Dinan, 2012; Foster and McVey Neufeld, 2013; Tillisch, 2014).”

“On 100 the basis of these and other results it has been suggested that pro101 biotics may serve as adjuvant or preventive therapy for depression 102 (for reviews see Logan and Katzman, 2005; Cryan and Dinan, 2012; 103 Foster and McVey Neufeld, 2013; Tillisch, 2014). 104 These novel discoveries come at an opportune tim…”

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“…that individuals who typically respond to low mood by ruminating about possible causes and consequences of their state have more difficulties in recovering from depression (Nolen-Hoeksema et al., 1993; Kuehner and Weber, 1999; Nolen-Hoeksema, 2000; Spasojevic and Alloy, 2001; Moulds et al., 2008).”

“To calculate Bayesian probabilities we used the method proposed by Wagenmakers (2007) and Masson (2011).”

“This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). q This work was supported by a research grant from The Netherlands Organization for Scientific Research (NWO) awarded to Lorenza S. Colzato (Vidi Grant: #452- 12-001).”

“release immune activating and other signaling molecules that may play an important role in regulating the brain and subsequent behavior (Mayer, 2011; Cryan and Dinan, 2012; Foster and McVey Neufeld, 2013).”

“The BDI–II has been found to be a valid indicator of depression and show good diagnostic discrimination (Dozois et al., 1998).”

“…sources of serotonin released in the brain), the anterior cingulate cortex (ACC) and the prefrontal cortex (PFC; Thayer and Lane, 2007), in particular the mPFC (Mayer et al., 2006) – i.e., one of the brain regions associated with the processing of affective and social information (Adolphs, 2001).”

“|D) and p(H1|D), assuming a ‘‘unit information prior’’ (for further details, see Kass and Wasserman (1995); see also Jarosz and Wiley (2014)).”

“…that individuals who typically respond to low mood by ruminating about possible causes and consequences of their state have more difficulties in recovering from depression (Nolen-Hoeksema et al., 1993; Kuehner and Weber, 1999; Nolen-Hoeksema, 2000; Spasojevic and Alloy, 2001; Moulds et al., 2008).”

“Thus, our results show that the intake of multispecies probiotics for a 4-week period significantly reduced overall cognitive reactivity to depression and in particular aggressive and ruminative thoughts.”

“|D) and p(H1|D), assuming a ‘‘unit information prior’’ (for further details, see Kass and Wasserman (1995); see also Jarosz and Wiley (2014)).”

“…and the raphe nuclei (the principal sources of serotonin released in the brain), the anterior cingulate cortex (ACC) and the prefrontal cortex (PFC; Thayer and Lane, 2007), in particular the mPFC (Mayer et al., 2006) – i.e., one of the brain regions associated with the processing of affective and…”

“These genera have been found to be effective in ameliorating anxious and depressive symptoms (Benton et al., 2006; Rao et al., 2009; Yamamura et al., 2009; Desbonnet et al., 2010; Bravo et al., 2011; Messaoudi et al., 2011).”

“For example, it has been proposed that intestinal microbiota increase plasma tryptophan levels, and hereby potentially facilitate serotonin turnover in the brain (Desbonnet et al., 2008, 2010).”

“To calculate Bayesian probabilities we used the method proposed by Wagenmakers (2007) and Masson (2011).”

“…that individuals who typically respond to low mood by ruminating about possible causes and consequences of their state have more difficulties in recovering from depression (Nolen-Hoeksema et al., 1993; Kuehner and Weber, 1999; Nolen-Hoeksema, 2000; Spasojevic and Alloy, 2001; Moulds et al., 2008).”

“These genera have been found to be effective in ameliorating anxious and depressive symptoms (Benton et al., 2006; Rao et al., 2009; Yamamura et al., 2009; Desbonnet et al., 2010; Bravo et al., 2011; Messaoudi et al., 2011).”

“These genera have been found to be effective in ameliorating anxious and depressive symptoms (Benton et al., 2006; Rao et al., 2009; Yamamura et al., 2009; Desbonnet et al., 2010; Bravo et al., 2011; Messaoudi et al., 2011).”

“These genera have been found to be effective in ameliorating anxious and depressive symptoms (Benton et al., 2006; Rao et al., 2009; Yamamura et al., 2009; Desbonnet et al., 2010; Bravo et al., 2011; Messaoudi et al., 2011).”

“…that are activated when an individual experiences sad mood predicts whether the sad mood will be transient or will persist, and predicts the development of clinical depression (Abramson et al., 1989; Beck, 1967; Kovacs and Beck, 1978; Haaga et al., 1991; Scher et al., 2005; Ingram et al., 2006).”

“…of specific genera) can have increased effectiveness through an additive effect of specific strain properties such as colonization of different niches, enhanced adhesion and induction of an optimal pH range, as compared to monospecies supplements (Timmerman et al., 2004; Chapman et al., 2011).”

“Stimulation of the vagus nerve has already been described as a successful method to treat patients suffering from depression (Nemeroff et al., 2006).”

“…that are activated when an individual experiences sad mood predicts whether the sad mood will be transient or will persist, and predicts the development of clinical depression (Abramson et al., 1989; Beck, 1967; Kovacs and Beck, 1978; Haaga et al., 1991; Scher et al., 2005; Ingram et al., 2006).”

“…that are activated when an individual experiences sad mood predicts whether the sad mood will be transient or will persist, and predicts the development of clinical depression (Abramson et al., 1989; Beck, 1967; Kovacs and Beck, 1978; Haaga et al., 1991; Scher et al., 2005; Ingram et al., 2006).”

“While most of this research is relatively recent, and predominantly involves animal and pre-clinical human studies, the results appear in support of this hypothesis (Logan and Katzman, 2005; Cryan and Dinan, 2012; Foster and McVey Neufeld, 2013; Tillisch, 2014; Savignac et al., 2015).”

“Indeed, cognitive reactivity is considered one of the most predictive vulnerability markers of depression (Beck, 1967; Segal et al., 1999, 2006; Moulds et al., 2008).”

“Notably, studies have shown 436 that the tendency to engage in ruminative thoughts is sufficient 437 to turn mood fluctuations into depressive episodes, and that 438 individuals who typically respond to low mood by ruminating 439 about possible causes and consequences of their state have more 440 difficulties in recov…”

“Further, the activation of aggressive thoughts has been associated with suicidal ideation and attempts (Oquendo et al., 2006; Mann et al., 2008).”

“E-mail addresses: L.Steenbergen@fsw.leidenuniv.nl (L. Steenbergen), R.Sellaro@ fsw.leidenuniv.nl (R. Sellaro), S.vanHemert@winclove.nl (S. van Hemert), J.A.Bosch@ uva.nl (J.A. Bosch), Colzato@fsw.leidenuniv.nl (L.S. Colzato).”

“The total score is calculated by adding-up all items, hence scores range between 0 and 63 (0–13: minimal depression, 14–19: mild depression, 20–28: moderate depression and 29–63: severe depression; van der Does, 2002a).”

“⇑ Corresponding author at: Leiden University, Institute for Psychological Research, Cognitive Psychology, Wassenaarseweg 52, 2333 AK Leiden, The Netherlands.”

“Internal consistency (Cronbach’s alpha; a) is 0.89 for the LEIDS total score, and ranges between 0.62 (Acceptance/Coping) and 0.84 for the subscales (Hopelessness/Suicidality; Antypa and van der Does, 2010; Williams et al., 2008).”

“On the basis of these and other results it has been suggested that probiotics may serve as adjuvant or preventive therapy for depression (for reviews see Logan and Katzman, 2005; Cryan and Dinan, 2012; Foster and McVey Neufeld, 2013; Tillisch, 2014).”

“Animal studies have further suggested that gut-to-brain signals are transmitted via the vagus nerve (Ter Horst and Postema, 1997; Tillisch et al., 2013).”

“These genera have been found to be effective in ameliorating anxious and depressive symptoms (Benton et al., 2006; Rao et al., 2009; Yamamura et al., 2009; Desbonnet et al., 2010; Bravo et al., 2011; Messaoudi et al., 2011).”

“…reactivity to transient changes in sad mood was measured by means of the revised Leiden Index of Depression Sensitivity (LEIDS-r; van der Does and Williams, 2003), which has been shown to be predictive of depression in multiple longitudinal studies (van der Does, 2005; Kruijt et al., 2013).”

“Interestingly, cognitive reactivity to sad mood has been associated with serotonin concentrations, with higher scores correlating with lower serotonin levels (Booij and Van der Does, 2007; Wells et al., 2010; see also Firk and Markus, 2009).”

“The batch used for the present experiments contained >2.5 109 CFU/g, whereas the placebo contained 1 104 CFU/g. Rehydration of freeze-dried lactic acid bacteria in milk, water and physiological salt solution has been shown to result in equal survival rates (de Valdez et al., 1985).”

“Internal consistency (Cronbach’s alpha; a) is 0.89 for the LEIDS total score, and ranges between 0.62 (Acceptance/Coping) and 0.84 for the subscales (Hopelessness/Suicidality; Antypa and van der Does, 2010; Williams et al., 2008).”

“The intestine and the brain are intimately connected via the brain-gut axis, which involves bidirectional communication via neural, endocrine and immune pathways (Grossman, 1979; Grenham et al., 2011; Mayer, 2011; Mayer et al., 2014).”

“…found to predict depression incidence in multiple longitudinal studies and to correlate with depression risk factors, such as depression history (Moulds et al., 2008), genetic markers of depression (Antypa and van der Does, 2010), and reaction to tryptophan depletion (Booij and van der Does, 2007).”

“The M.I.N.I. is a short structured interview, taking about 15 min, which screens for several psychiatric disorders (Sheehan et al., 1998; Colzato et al., 2008, 2010).”

“Thus, our results show that the intake of multispecies probiotics for a 4-week period significantly reduced overall cognitive reactivity to depression and in particular aggressive and ruminative thoughts.”

“Each bacterial strain of the multispecies probiotics used in this study has been found to improve epithelial barrier function both when tested separately and in combination (Van Hemert and Ormel, 2014).”

“…of small studies in healthy individuals suggest pre- and probiotic consumption can positively affect aspects of mood and anxiety (Messaoudi et al., 2011; Steenbergen et al., 2015), modulate HPA function (Messaoudi et al., 2011; Schmidt et al., 2015) and alter brain activity (Tillisch et al., 2013).”