2 results
The effectiveness of a Lactobacillus probiotic on measures of psychosocial health in adults diagnosed with subthreshold depression: a double-blind, randomised, placebo-controlled trial
- G. Moschonis, K. Sarapis, S. Resciniti, R. Hall, K. Yim, M. Tonkovic, C. Fitzgerald, F. Anixiadis, Q. Nhu Dinh, M. Hale, B. Wright, M. Pane, C.J. Tuck, J.R. Biesiekierski
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- Journal:
- Proceedings of the Nutrition Society / Volume 83 / Issue OCE1 / April 2024
- Published online by Cambridge University Press:
- 07 May 2024, E58
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Depression is the leading cause of disability worldwide(1). The microbiota-gut-brain axis may play a role in the aetiology of depression, and probiotics show promise for improving mood and depressive state(2). Further evidence is required to support mechanisms and in high-risk populations, such as those with sub-threshold depression (which may be 2-3 times more prevalent than diagnosed depression)(3). The aims were to assess the efficacy of a probiotic compared with placebo in reducing the severity of depressive symptoms in participants with subthreshold depression, and to investigate potential mechanistic markers of inflammatory, antioxidant status and stress response. A double-blind, randomised, placebo-controlled trial was conducted in participants meeting diagnosis of subthreshold depression (DSM-5); aged 18-65 years; ≥18.5 kg/m2 body mass index; not taking antidepressants, centrally acting medications, probiotics nor antibiotics for at least 6 weeks. The probiotic (4 × 109 AFU/CFU, 2.5 g freeze-dried powder containing Lactobacillus fermentum LF16 (DSM26956), L. rhamnosus LR06 (DSM21981), L. plantarum LP01 (LMG P-21021), Bifidobacterium longum BL04 (DSM 23233)) or placebo was taken daily for 3-months. Data was collected at 3 study visits (pre-, mid- (6 weeks), post-intervention). Self-reported questionnaires measured psychological symptoms (Beck Depression Inventory, BDI; Hospital Anxiety Depression Scale, HADS) and quality of life. Blood and salivary samples were collected for biomarkers including cortisol awakening response (CAR). General linear models examined within-group and between-group differences across all time points. Thirty-nine participants completed the study (n = 19 probiotic; n = 20 placebo) using intention-to-treat analysis. The probiotic group decreased in BDI score by −6.5 (95% CI −12.3; −0.7) and −7.6 (95% CI −13.4; −1.8) at 6 and 12 weeks, respectively. The HADS-A score decreased in the probiotic group by −2.8 (95% CI −5.2; −0.4) and −2.7 (95% CI −5.1; −0.3) at 6 and 12, respectively. The HADS-D score decreased in the probiotic group by −3.0 (95% CI −5.4; −0.7) and −2.5 (−4.9; −0.2) at 6 and 12 weeks of intervention, respectively. No between group differences were found. There were no changes in perceived stress or quality of life scores. The probiotic group had reduced hs-CRP levels (7286.2 ± 1205.8 ng/dL vs. 5976.4 ± 1408.3; P = 0.003) and increased total glutathione (14.2 ± 8.9 ng/dL vs. 9.3 ± 4.7; P = 0.049) compared to placebo, post intervention. Lower levels of CAR were found in the probiotic compared to placebo (−0.04 ± 0.17 μg/dL vs. 0.16 ± 0.25; P = 0.009). A significant reduction in depressive symptoms and anxiety was observed within the probiotic group only. These results were supported by improvements observed in biomarkers, suggesting probiotics may improve psychological wellbeing in adults experiencing sub-threshold depression, by potential pathways involved in central nervous system homeostasis and inflammation. Future analyses are required to understand changes within the intestinal microbiota and to clarify how their metabolites facilitate emotional processing.
Predicting symptom response and quality of life to the low FODMAP diet in irritable bowel syndrome: a 6-month longitudinal study
- L.P. Manning, C.J. Tuck, M. Van den Houte, L. Van Oudenhove, J.R. Biesiekierski
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- Journal:
- Proceedings of the Nutrition Society / Volume 83 / Issue OCE1 / April 2024
- Published online by Cambridge University Press:
- 07 May 2024, E65
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- Article
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The low fermentable oligosaccharide, disaccharide, monosaccharide and polyol (FODMAP) diet is recommended as a first line therapeutic management strategy for irritable bowel syndrome (IBS)(1). The low FODMAP diet is supported by meta-analytical evidence(2), and demonstrates acceptability and effectiveness for improving symptoms and quality of life (QoL) in 50-75% of individuals with IBS. However, a subset of individuals (25-50%) do not respond to the diet(3). The identification of individual-level predictors of treatment response across all three phases of the low FODMAP diet is currently lacking. The study aims were to assess psychological predictors of symptom and QoL response to the low FODMAP diet in patients with IBS. Adults with IBS underwent a three-phase low FODMAP diet, guided by individualised dietetic education. Predictor variables included levels of depressive, anxiety, and extraintestinal somatic symptoms, stress, treatment beliefs and expectations, behavioural avoidance, and illness perceptions. Symptom severity and QoL were the main outcomes. Questionnaires assessing psychological predictors, symptoms and QoL were administered at five points: pre-dietitian (week 0), post-dietitian, end of elimination (week 5), end of reintroduction (week 13), and end of personalisation (week 25) phases. Latent class growth analysis was used to identify classes of response trajectories for symptoms. Linear mixed models were used to test the effect of baseline psychological scores on symptoms and QoL over time. Cross lagged panel models determined the directional predictive relationship between psychological predictors and symptom severity. 112 participants (89% F) median age 30 ± 17 years were included. There were three classes of symptom response trajectories, including ‘non-improvers’ (21.3% of participants) with high initial symptom severity and minimal improvement, ‘improvers’ (22.5% of participants) with low initial symptom severity and significant improvement, and an ‘intermediate’ group (56.2% of participants) with moderate initial symptom severity and significant improvement. Higher treatment beliefs predicted a stronger initial symptom response (effect on linear slope p = 0.036). Lower gut-specific anxiety, as well as higher levels of personal and treatment control at baseline predicted a stronger reduction in IBS symptom severity and improved QoL from week 0 to week 25. Participants with higher levels of baseline psychological symptoms and negative illness perceptions (i.e., lower emotional representations) predicted a stronger initial and later QoL response (effect on linear (p = 0.006) and quadratic (p = 0.049) slopes). Increased cyclical time beliefs predicted poorer initial and later QoL response (effect on linear (p = 0.015) and quadratic (p = 0.029) slopes). Individuals experiencing lower to mid-range symptom severity at baseline had greater improvement with the low FODMAP diet. Lower anxiety, positive illness views and higher treatment beliefs predict better QoL and symptom response. Personalised strategies are crucial for optimising low FODMAP diet effectiveness in IBS.